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In this paper we describe the process used to create the interference waveform used in radiated interference testing and demonstrate two examples of how such a signal may be used in testing the performance of wireless devices. Our goal is to simulate, in a laboratory environment, typical to worst-case conditions for wireless electronic safety devices used by emergency responders. The methods discussed were developed with repeatability in mind and are general enough to be applicable to a wide variety of interference tests.

Objective This study assessed neurovascular complications in the surgical management of carotid body tumors (CBTs), with emphasis on those treated with and without preoperative embolization. Methods We reviewed the clinical data of all consecutive patients with CBTs treated by surgical resection at our institution from 1985 to 2010. Outcomes were compared between Shamblin class II and III CBTs treated with preoperative embolization (EMB group) and with no preoperative embolization (NEMB group). Results A total of 131 patients (80 women, 51 men), who were aged 48 years (range, 16-84 years), had resection of 144 CBTs and 12 concurrent cervical paragangliomas. This included 18 patients who had bilateral resections and 29 with familial CBTs. Succinate dehydrogenase ( SDHx ) mutations were confirmed in 17 patients. Mean tumor volume was 20.5 cm 3 (range, 0.8-101.3 cm 3 ), and there were two biochemically active CBTs (1%). There were 71 Shamblin II and 33 Shamblin III. The EMB group underwent 33 CBT resections, and the NEMB group underwent 71. There were more patients in the EMB group with bilateral (48% vs 22%; P = .01) and familial (34% vs 14%; P = .01) CBT; otherwise, patient demographics, Shamblin class, and tumor diameter and volumes were similar. No strokes or other major complications occurred after preoperative embolization with polyvinyl alcohol particles 1 day before surgery. The EMB group required less extensive procedures (simple excision in 97% vs 82%, P = .03; internal carotid artery clamping in 15% vs 37%, P = .04) and had less blood loss (mean estimated blood loss, 263 vs 599 mL; P = .002) than the NEMB group. However, there were no significant differences in operative time (250 vs 265 minutes; P = .49), temporary cranial nerve injury (52% vs 38%; P = .21), clinically apparent cranial nerve deficits after 1 year (12% vs 7%; P = .46), deaths (0% vs 0%; P > .99), stroke (0% vs 1%; P > .99), or postoperative length of stay (4.1 vs 4.2 days; P = .91). Conclusions Large CBTs can be resected safely with or without preoperative embolization. Preoperative embolization may simplify the conduct of the operation and reduce blood loss but does not decrease rates of cranial nerve injury, although most are temporary.

Many serologic and radiographic modalities are used for monitoring multiple endocrine neoplasia type 1 (MEN 1) patients for pancreaticoduodenal neuroendocrine tumors (PNETs). We compared serum markers and imaging studies obtained preoperatively with the gross pathology and immunohistochemical findings and correlated preoperative testing with postoperative outcome.From 2000 to 2008, 52 MEN 1 patients [32 (62%) female; median age = 43 years, range 19-74 years] underwent 56 pancreatic operations [49 (88%) distal pancreatectomies] for suspected PNETs. Preoperative serum markers [human pancreatic polypeptide (HPP), gastrin, and glucagon] and imaging [CT, (111)In pentetreotide scintigraphy, and endoscopic ultrasound (EUS)] were compared to the pathologic findings. Postoperative serum markers and survival were followed.Human pancreatic polypeptide had the highest agreement between an elevated serum level and positive tumor immunostaining (83% vs. 50% agreement for gastrin vs. 67% agreement for glucagon). Preoperative CT had 81% sensitivity and positive predictive value (PPV) of 97% for PNETs. (111)In pentetreotide scintigraphy had 84% sensitivity and PPV of 96%. Preoperative endoscopic ultrasonography (EUS) had 100% sensitivity and PPV, with close correlation (r (s) = 0.93) between the largest lesion seen on EUS and pathology. Median follow-up was 4.3 years (range = 0.1-10.9 years). Overall survival was 89% at 5-year follow-up.Our study substantiates EUS as providing the highest preoperative sensitivity and PPV in assessing the presence of PNETs in MEN 1 patients. CT and octreotide scintigraphy can yield both false-positive and false-negative results. HPP, gastrin, and glucagon were the most commonly measured tumor markers in our series but did not always correlate with immunostaining. With an aggressive surgical approach, satisfactory rates of biochemical improvement and long-term survival were observed.

In this paper, we discuss a three-antenna reverberation-chamber method that allows for the determination of the antenna efficiency. While reverberation chambers have been used in the past for determining antenna efficiency, the previous approaches required knowledge of the efficiency of a reference antenna. The approach discussed in this paper allows one to determine the efficiency of one or all three antennas, and does not require one to know the efficiency of any of the antennas under test beforehand. The technique combines both time-domain and frequency-domain processed data, collected in reverberation-chamber experiments. Combining data in these two domains for three sets of experiments (a set for each two-antenna combination of the three antennas under test) allows for the determination of the efficiencies of the three unknown antennas. In this paper, we discuss the technique and present experimental data in order to illustrate its validity.

Pheochromocytoma in pregnancy is a rare condition with an estimated incidence of one in 54,000 pregnancies. Pheochromocytoma in the setting of multiple endocrine neoplasia (MEN) type 2A develops in approximately 40% of the patients with this germline mutation. MEN 2A patients with pheochromocytoma are often asymptomatic compared to those with nonsyndromic pheochromocytoma. We present a 28-year-old pregnant woman with a known MEN 2A mutation who was incidentally found to have a pheochromocytoma. She underwent an uncomplicated laparoscopic right adrenalectomy after proper α- and α-adrenergic blockade. Her serum fractionated metanephrines normalized prior to discharge from the hospital. The remainder of her pregnancy was uneventful and she delivered a health baby at term. Pheochromocytoma in pregnancy requires careful management to assure the well being of both the mother and the fetus. In pregnancy, laparoscopic surgical removal of the pheochromocytoma is feasible with excellent results when performed in the second trimester. In late pregnancy, medical management with close monitoring of the mother and fetus is recommended until fetal maturity is achieved. In the third trimester, cesarean section followed by open adrenalectomy is the preferred operation. An integrated and multidisciplinary approach with close communication among the endocrinologist, surgeon and perinatal services is paramount to achieve excellent outcomes for both patients. Women with MEN 2 should be advised to refrain from pregnancy until updated biochemical and imaging studies have ruled out pheochromocytoma. How to cite this article Dy BM, Podgaetz E, Young WF, Thompson GB. Pheochromocytomas, MEN 2A and Pregnancy: A Case Report with Review of the Literature. World J Endocr Surg 2012;4(1):29-32.

We describe the development of free-field test methods for wireless electronic safety equipment that replicate field-test conditions in a laboratory environment. The test methods can be used to verify the performance of wireless devices, such as those used by emergency responders, in the presence of known attenuation and under RF interference conditions. The test methods presented here were developed to support the National Fire Protection Association (NFPA) in the revision of NFPA 1982: Standard on Personal Alert Safety Systems (PASS), but would be applicable to other types of RF-based equipment as well. In Part 1, we illustrate methods for extracting performance metrics from a series of field tests conducted by NIST researchers. In Part 2, we replicate the key field-test conditions in the laboratory and verify device performance under those conditions.

McCune-Albright syndrome (polyostotic fibrous dysplasia, café-au-lait skin spots, and precocious puberty) is a genetically mosaic disorder with populations of mutant and normal cells in affected organs. Cushing syndrome, a rare feature of the condition, usually affects infants and is the result of corticotropin-independent primary bilateral adrenal disease, usually interpreted as nodular adrenocortical hyperplasia. In this study of 9 patients with Cushing syndrome and McCune-Albright syndrome, light microscopy revealed a characteristic bimorphic pattern of diffuse and nodular hyperplasia and a distinctive form of cortical atrophy with apparent zona glomerulosa hyperplasia in 8 patients, all very young. The pattern could be explained by the presence of a mosaic distribution of mutant and normal cells in the adrenal glands. The findings are different from those in inherited or other forms of genetically caused Cushing syndrome. The ninth patient, aged 17 years, had an adrenal adenoma and diffuse cortical hyperplasia in each adrenal gland.

Background Historically, treatment of confirmed primary aldosteronism has been adrenalectomy for unilateral adenoma; bilateral hypersecretion is treated medically. Increasingly, we use adrenal venous sampling (AVS) to define unilateral hypersecretion. Histology of glands resected based on AVS often reveals multiple nodules or hyperplasia. The aim of this study was to compare patients with multiple nodules or hyperplasia with those with single adenoma with regard to cure, preoperative imaging, AVS ratio, and biochemical evaluation to determine if a nonsingle adenoma (NSA) process could be predicted to impact extent of adrenalectomy. Study Design This was a retrospective study reviewing a single-institutional surgical experience at a tertiary academic center from 1993 to 2008, during which 215 patients with primary aldosteronism underwent unilateral adrenalectomy based on imaging of a single adenoma (normal contralateral gland) or AVS ratios. Histology included single adenoma versus NSA; cure was defined as normal immediate postoperative plasma or urine aldosterone level, normal aldosterone:renin ratio, or normotension without antihypertensive medications. Results Follow-up (mean 13 months, range 0 to 185 months) was available for 167 patients: 132 (79%) single adenoma and 35 (21%) NSA. All 35 patients with NSA and 128 patients (97%) with single adenoma were cured. Imaging studies correctly predicted NSA in 29% and 57% when combined with AVS. Identifying patients with NSA preoperatively was impossible biochemically: mean serum and urinary aldosterone levels and AVS ratios were not different than those of the single adenoma group. Conclusions Twenty-one percent of patients had NSA, all cured by unilateral adrenalectomy. No preoperative evaluation reliably predicted NSA. Therefore, total unilateral adrenalectomy was safest given the potential for incomplete resection with partial adrenalectomy. Accurate AVS is highly predictive of cure irrespective of the unilateral adrenal histology.

Eplerenone is claimed to be a more selective blocker of the mineralocorticoid receptor than spironolactone being associated with fewer antiandrogenic side-effects. We compared the efficacy, safety and tolerability of eplerenone versus spironolactone in patients with hypertension associated with primary aldosteronism.The study was multicentre, randomized, double-blind, active-controlled, and parallel group design. Following a single-blind, placebo run-in period, patients were randomized 1: 1 to a 16-week double-blind, treatment period of spironolactone (75-225 mg once daily) or eplerenone (100-300 mg once daily) using a titration-to-effect design. To be randomized, patients had to meet biochemical criteria for primary aldosteronism and have a seated DBP at least 90 mmHg and less than 120 mmHg and SBP less than 200 mmHg. The primary efficacy endpoint was the antihypertensive effect of eplerenone versus spironolactone to establish noninferiority of eplerenone in the mean change from baseline in seated DBP.Changes from baseline in DBP were less on eplerenone (-5.6 ± 1.3 SE mmHg) than spironolactone (-12.5 ± 1.3 SE mmHg) [difference, -6.9 mmHg (-10.6, -3.3); P0.001]. Although there were no significant differences between eplerenone and spironolactone in the overall incidence of adverse events, more patients randomized to spironolactone developed male gynaecomastia (21.2 versus 4.5%; P=0.033) and female mastodynia (21.1 versus 0.0%; P=0.026).The antihypertensive effect of spironolactone was significantly greater than that of eplerenone in hypertension associated with primary aldosteronism.

To describe the unique association of corticotropin-independent Cushing syndrome caused by cortisol- and androgen-secreting black adrenal cortical adenomas with myelolipomatous change.We report the clinical, laboratory, radiologic, and pathologic findings from 2 patients who presented with androgen excess and typical signs and symptoms of Cushing syndrome.Endocrine investigations showed high serum cortisol concentrations that lacked diurnal rhythm, undetectable plasma corticotropin concentrations, and absence of serum cortisol suppression after overnight dexamethasone suppression tests. Serum levels of adrenal androgens were elevated. Computed tomography of the abdomen revealed unilateral adrenal masses (largest lesional diameters 4.0 and 3.1 cm). On the basis of the plurihormonal hypersecretion and the imaging characteristics, adrenocortical carcinoma was considered as a possible diagnosis. However, histopathologic analysis in both patients revealed black adrenal cortical adenomas with myelolipomatous change. After surgery, adrenal androgens normalized, and the signs and symptoms of Cushing syndrome and androgen excess resolved. There was no evidence of recurrent disease at last follow-up.A unique form of corticotropin-independent Cushing syndrome is described: cortisol- and androgen-secreting black adrenal cortical adenomas with myelolipomatous change. Although most patients with corticotropin-independent Cushing syndrome associated with androgen excess prove to have adrenocortical carcinoma, the clinician should be aware of the possibility of benign, black adrenal adenomas in this clinical setting.

Objective To review the first reported cases of successfully treated pheochromocytoma and primary aldosteronism and to document the diagnostic and therapeutic advances that have occurred since the initial descriptions. Methods The original case descriptions and the subsequent pertinent literature were reviewed. Results The successful management of the initial cases of pheochromocytoma in 1926 and primary aldosteronism in 1954 was highlighted by keen clinical observation, clinical intuition, and application of scientific principles. Since those prismatic case descriptions, the technological advances in laboratory-based diagnosis, radiology-based tumor localization, and surgical approaches to the adrenal glands have been truly remarkable. Conclusions The evolution in the diagnosis and treatment of pheochromocytoma will continue to progress as we identify more genetic causes, develop biochemical markers for “preclinical” pheochromocytoma, identify better markers for malignant disease, and develop more effective treatment options for malignant pheochromocytoma. Over the next decade, we hope to determine the pathophysiology for bilateral idiopathic hyperaldosteronism, develop less invasive and less technically demanding tests to distinguish between unilateral aldosterone-producing adenoma and bilateral idiopathic hyperaldosteronism, determine where low renin hypertension stops and primary aldosteronism starts, and determine the impact of genetic and environmental factors on aldosterone secretion in patients with and without primary aldosteronism. (Endocr Pract. 2010:16:888-902)

OBJECTIVE: To analyze the factors associated with anterior pituitary deficits after pituitary adenoma stereotactic radiosurgery (SRS). METHODS: The tumor, pituitary stalk, and pituitary gland were segmented on the dose plans of 82 patients (secreting tumors, n = 53; nonsecreting tumors, n = 29) for dose-volume analysis. No patient had undergone prior radiation therapy and all patients had at least 12 months of endocrinological follow-up (median, 63 months; mean, 69 months; range, 13-134). RESULTS: Thirty-four patients (41 %) developed new anterior pituitary deficits at a median of 32 months (range, 2-118) after SRS.The risk of developing new anterior pituitary deficits was 16% and 45% at 2 and 5 years, respectively. Multivariate analysis of the entire group showed that poor visualization of the pituitary gland (hazard ratio [HR] = 2.63, 95% confidence interval [CI] = 1.10-6.25, P = .03) was associated with a higher rate of new anterior pituitary deficits. Dosimetric analysis of 60 patients whose pituitary gland could be clearly identified showed that increasing mean pituitary gland radiation dose correlated with new anterior pituitary deficits (HR = 1.11, 95% CI = 1.02-1.20, P = .02). New anterior pituitary deficits stratified by mean pituitary gland radiation dose: ≤7.5 Gy, 0% (0/7); 7.6 to 13.2 Gy, 29% (7/24); 13.3 to 19.1 Gy, 39% (9/23); > 19.1 Gy, 83% (5/6). CONCLUSION: New endocrine deficits after pituitary adenoma radiosurgery were correlated with increasing radiation dose to the pituitary gland. Methods that limit the radiation dose to the pituitary gland during SRS may increase the probability of preserving pituitary function.

We report on our investigation into radio communications problems faced by emergency responders in disaster situations. A fundamental challenge to communications into and out of large buildings is the strong attenuation of radio signals caused by losses and scattering in the building materials and structure. Another challenge is the large signal variability that occurs throughout these large structures. We designed experiments in various large building structures in an effort to quantify continuous wave (CW) radio-signal attenuation and variability throughout twelve large structures. We carried radio frequency transmitters throughout these structures and placed receiving systems outside the structures. The transmitters were tuned to frequencies near public safety, cell phone bands, as well as ISM and wireless LAN bands. This report summarizes the experiments, performed in twelve large building structures. We describe the experiments, detail the measurement system, show primary results of the data we collected, and discuss some of the interesting propagation effects we observed.

We report on measurements that characterize multipath conditions that affect broadband wireless communications in building penetration scenarios. Measurements carried out in various large structures quantify both radio-signal attenuation and distortion (multipath) in the radio propagation channel. Our study includes measurements of the complex, wideband channel transfer function and bandpass measurements of a 20 MHz-wide, digitally modulated signal. From these, we derive the more compact metrics of time delay spread, total received power and error vector magnitude that summarize channel characteristics with a single number. We describe the experimental set-up and the measurement results for data collected in representative structures. Finally, we discuss how the combination of propagation metrics may be used to classify different propagation channel types appropriate for public-safety applications.

Pheochromocytomas are rare, but potentially fatal, neoplasms. The diagnosis and localization of pheochromocytoma can be challenging, and recently there has been some debate regarding the role for adrenal venous sampling (AVS). The utility of AVS in this setting is hampered by a lack of normative value data for adrenal vein catecholamine concentrations and the reliability of lateralization ratios. We sought to address these concerns by analyzing AVS catecholamine concentrations from patients who did not have pheochromocytoma.Eighteen patients underwent successful AVS for evaluation of cortisol-producing adrenal masses. All had normal 24-h urinary excretion of fractionated catecholamines and metanephrines.There was a wide range of catecholamine concentrations in both the right (epinephrine 389-118326 pg/ml; norepinephrine 156-11193 pg/ml) and left (epinephrine 113-9327 pg/ml; norepinephrine 229-2216 pg/ml) adrenal veins. The right adrenal vein-to-left adrenal vein epinephrine gradient was as high as 83:1 (median 2.1:1; P0.02). Although less striking, similar findings were also seen for norepinephrine.This report provides a reference range for adrenal vein catecholamine concentrations in nonpheochromocytoma patients and illustrates the wide variation in epinephrine and norepinephrine concentrations. Epinephrine and norepinephrine concentrations are statistically significantly higher in the right vs. the left adrenal vein; in the case of epinephrine, up to an 83-fold difference was found between the right and left adrenal veins. These data highlight why AVS should not be used in the investigation of adrenal pheochromocytoma.

Carney triad, as originally described in 1977, was the association of 3 tumors: gastric epithelioid leiomyosarcoma [later renamed gastrointestinal stromal tumor (GIST)], extra-adrenal paraganglioma, and pulmonary chondroma. The disorder affected mostly young women and was not familial. We studied the clinical and pathologic features of the gastric neoplasm in 104 patients with the syndrome. Most (88%) were young women (mean age, 22 y), and the usual presentation was gastric bleeding. The tumors, commonly antral-based (61%), were multifocal, and ranged from 0.2 to 18.0 cm in dimension. Most (86%) featured round and polygonal (epithelioid) cells. Metastasis occurred in 49 patients (47%): to gastric lymph nodes (29%), liver (25%), and peritoneum (13%). Immunopositivity was detected in the tumors tested as follows: KIT, 100%; CD34, 75%; PKCtheta, 21%; PDGFRA, 90%; and smooth muscle actin, 6%. Fourteen patients (13%) died of metastatic GIST at a mean age of 45 years (range, 30 to 69 y). Estimated 10 and 40-year survivals were 100% and 73%, respectively. Median survival time was 26.5 years (range, 16 to 60 y). There was no correlation between the National Institutes of Health tumor risk classification and the tumor behavior. Compared with sporadic gastric GISTs, the gastric stromal tumor in Carney triad showed distinctive features: female predilection, young patient age, epithelioid cell predominance, multifocality, frequent lymph node metastasis, serial tumor occurrence, and unpredictable behavior. Thus, the Carney triad gastric stromal tumor is different clinically, pathologically, and behaviorally from sporadic gastric GIST.

Study Background Patients who experience a recurrent laryngeal nerve injury (RLI) after undergoing an Anterior Cervical Discectomy and Fusion (ACDF) procedure may eventually become asymptomatic. If patients with an asymptomatic vocal cord abnormality undergo a subsequent ACDF they may be at risk for developing bilateral vocal cord paralysis (VCP). Bilateral VCP is a potentially life threatening problem, requiring emergent tracheotomy in some cases. A program of referring patients for preoperative laryngoscopic examinations (PLE) who were being considered for a revision ACDF was instituted. This study reviews the results of these examinations and determines if the information gained impacted management. Methods Patients who were referred for PLE prior to revision ACDF were identified from a prospectively maintained database during the period 2004 – 2010. All patients underwent examinations by an Otorhinolaryngologist specialist (ENT) using a nasopharyngoscope in combination with video stroboscopic examination. Results 23 patients were identified as having a PLE and subsequent revision ACDF. 18 patients underwent a single level ACDF and 5 patients underwent a previous 2 level surgery. Significant findings were found in 4 patients. 2 patients presented with asymptomatic VCP and 2 patients with chronic hoarseness. One was found with VCP and the other with a vocal cord mass. The revision procedures were performed on the same side as the previous ACDF. Conclusions 17.3% of patients undergoing PLE exhibited abnormalities, affecting decision-making regarding side of approach for revision ACDF. PLE is a simple and effective way of screening patients for abnormalities prior to revision ACDF surgery.

Background Pheochromocytomas and paragangliomas are highly vascular neuroendocrine neoplasms that often secrete catecholamines. Percutaneous biopsy has been associated with life-threatening hemorrhage, hypertensive crisis, capsular disruption with tumor implantation, and death. We sought to determine the outcomes of biopsy in 20 consecutive patients. Methods We reviewed retrospectively the medical records of patients with biopsied pheochromocytomas and paragangliomas referred to our Endocrine Division for subsequent management between 1995 and 2005. Biopsy complications, operative findings, and outcomes were reviewed. Results Twenty patients (14 pheochromocytomas and 6 paragangliomas) were biopsied percutaneously prior to referral. Mean tumor diameter was 6.4 cm (range, 1–15). Pre-biopsy biochemical testing was not performed in 90% of patients, and was negative in the remainder. Fourteen patients (70%) developed a biopsy-related complication, including: increased difficulty of the definitive operation in 7 of 17 (41%) operative cases with 1 patient requiring conversion to an open procedure; severe hypertension (15%); hematoma (30%); incorrect or inadequate biopsy (25%); severe pain (25%); and delay in surgical treatment (15%). Mean follow-up was 58 months, with 4 tumor-related deaths and 2 recurrences. Conclusion Biochemical testing prior to biopsy of adrenal or suspicious retroperitoneal masses is critical to exclude a catecholamine-secreting neoplasm because serious complications and increased operative difficulty can result.

Objective To report 3 cases of primary neuroendocrine tumors (PNT) of the extrahepatic biliary tree (EHBT) in patients with Zollinger-Ellison syndrome (ZES), 2 of whom had multiple endocrine neoplasia type 1 (MEN 1). Methods Three new cases of gastrin-producing tumors of the EHBT are presented, and the pertinent literature relating to PNT of the EHBT is reviewed. Results Eighty-one previous cases of PNT of the EHBT have been reported in the world literature, 7 of which were hormonally active and associated with peptic ulcer disease, diarrhea, or ZES. Three additional patients presented to us with ZES due to PNT of the EHBT. One patient with MEN 1 was treated with a Whipple procedure for a common bile duct gastrinoma. A second patient underwent left hepatectomy with resection of the confluence of the right and left hepatic ducts for a primary left hepatic duct gastrinoma. The second patient with MEN 1 underwent resection of a gastrinoma at the junction of the cystic duct and the common bile duct. Conclusion Although PNT of the EHBT are uncommon, the association with ZES is even more so. Often, nonfunctioning tumors are diagnosed late in the course of the disease from symptoms related to biliary obstruction. Patients with ZES may be diagnosed earlier because of symptoms resulting from gastrin excess. Surgical resection is the only chance for cure and is often helpful in the palliation of symptoms. (Endocr Pract. 2009;15:737-749)

Summary Background Macroadenomas represent 50% of pituitary tumours and are often (30%) nonfunctioning. Their immunophenotype suggests differentiation toward a specific pituitary cell line. A substantial proportion of tumours with particularly aggressive behaviour are so called ‘silent subtype 3 adenoma’. Its diagnosis requires ultrastructural confirmation. Although once included among silent corticotroph adenomas, this aggressive, morphologically distinctive tumour is now recognized as a major form of plurihormonal adenoma and, in fact, some patients might present with clinical hormonal excess. The cytogenesis and pathobiology of silent subtype 3 adenomas is unsettled. Objective We undertook a systematic clinicopathologic examination of the Mayo Clinic experience with this poorly understood tumour. Design This retrospective, single institution study found 27 confirmed examples of silent subtype 3 adenoma, a frequency of 0·9% of adenomas. Despite histologic and immunophenotypic variation, their ultrastructural features were diagnostic and the sole basis for case inclusion. Results The study group was comprised of 16 men (59%) and 11 women (41%); two patients (7%) had definitive diagnosis of multiple endocrine neoplasia type 1 (MEN1). Three tumours (11%) were discovered incidentally. Nine patients each (38%) presented with headaches or visual field loss. Endocrine hyperfunction was noted in eight cases (30%), including GH excess in five (19%) and clinically significant PRL elevation in three (11%). Hypogonadism was noted in 17 cases (63%) and growth arrest in one (4%). All tumours were macroadenomas; 16 (60%) showed radiographic evidence of invasion. Most tumours were plurihormonal, featuring immunoreactivity for PRL (17), GH (15), TSH (16) or ACTH (3); only one lesion was immunonegative. Although a gross total resection was achieved in 19 cases (70%), re-operation for recurrence(s) was required in seven of these (37%). Follow-up (mean, 69 months) showed a high (59%) rate of persistent or recurrent of tumour. Overall, 14 patients (54%) underwent radiotherapy after surgical treatment: three patients (12%) for substantial residual tumour, eight (31%) as adjuvant therapy and three (12%) for tumour regrowth. Conclusion Silent subtype 3 adenoma, a plurihormonal tumour, is rare and aggressive in nature. This adenoma must be considered in the differential of often clinically nonfunctioning but plurihormonal adenomas featuring variable cytologic atypia. Electron microscopy is required for confirmation of the diagnosis. The cytogenesis of silent subtype 3 adenoma remains unsettled.

Emergency responders often experience poor quality wireless communications due to the complex radio-frequency propagation environment encountered at a typical emergency response location, such as an apartment complex, office building, or other large building structure. Our previous theoretical analysis in conjunction with simulation studies suggests that optimizing arrays of randomly located wireless transmitters can provide a significant increase in the received signal level for a receiver located in the array volume. Here we present experimental results from the application of our initial algorithm in representative complex propagation environments. Several different scenarios are included in the experiments to demonstrate the effectiveness of the optimization approach in an environment that contains a variety of scattering objects. For the various scenarios, we observed at least a 7 dB median gain over a single transmitter when the array consists of four transmitters.

Background Extra-adrenal catecholamine-secreting tumors are referred to as paragangliomas. We reviewed our experience with mediastinal paragangliomas treated at Mayo Clinic over the last 30 years. Methods Fourteen patients were identified who had resection of a mediastinal paraganglioma between 1973 and 2007. Perioperative data obtained from the medical record and follow-up information were reviewed. Results The median age of patients at operation was 39 years (range, 27 to 68 years), 71% were female, and all had a history of hypertension. Preoperative diagnosis of a catecholamine-secreting tumor was confirmed through elevated 24-hour urinary norepinephrine in 12 patients and tumor location was determined with metaiodobenzylguanidine scintigraphy, computed tomography or magnetic resonance imaging scans in the majority. The tumor was adjacent to the heart or great vessels in all patients and was resected through a median sternotomy (n = 10), or with posterolateral thoracotomy (n = 4). In 6 patients, cardiopulmonary bypass was used to facilitate dissection of the paraganglioma from the heart or great vessels. There was one intraoperative death in this series due to blood loss. Ten of the 11 patients were alive at follow-up (median follow-up: 2.3 years; range, 0 to 19.4 years). Symptoms of catecholamine excess were eliminated or greatly improved in all patients who had a functioning tumor preoperatively, but 6 of these patients were still being treated with antihypertensive medications. Conclusions Functional paragangliomas can be diagnosed with measurement of fractionated catecholamines and metanephrines; mediastinal localization is determined with appropriate scanning techniques. These tumors can be treated successfully by surgical resection with modest surgical risk, often necessitating cardiopulmonary bypass, with good long-term survival. Hypertension may persist even after complete resection of the tumor.

Reported biochemical remission rates have ranged widely after stereotactic radiosurgery for patients with hormone-secreting pituitary adenomas. Confounding variables include histology, radiation dose, use of pituitary-suppressive medications, and length of follow-up.A retrospective review of 46 patients with pituitary adenomas (growth hormone-secreting, n = 27; prolactin-secreting, n = 11; adrenocorticotropin-secreting, n = 8) undergoing radiosurgery between January 1990 and December 2003 was conducted. All received a tumor margin dose of 18 Gy or more and were off pituitary-suppressive medications for at least 1 month before radiosurgery. The groups were similar with regard to irradiated volume, radiation dose, and follow-up. The median endocrinological follow-up after radiosurgery was 54 months.The 4-year remission rates were 87% for patients with Cushing's disease, 67% for patients with acromegaly, and 18% for patients with prolactinomas. Patients with oversecretion of adrenocorticotropin or growth hormone were more likely to achieve remission after radiosurgery than patients with prolactinomas (hazard ratio, 4.4; 95% confidence interval, 1.1-18.2; P = 0.04). Of 44 patients with normal or partial anterior pituitary function before radiosurgery, 16 (36%) developed one or more new anterior pituitary deficits. The incidence of new anterior pituitary deficits was 26% at 4 years. No differences were noted in the incidence of new anterior deficits among the groups.There seems to be a differential sensitivity after radiosurgery for hormone-secreting pituitary adenomas. Remission rates are greater for patients with Cushing's disease and acromegaly, whereas radiosurgery is less effective in achieving biochemical remission for patients with prolactinomas.

Germline mutations in the genes encoding the B (SDHB) and D (SDHD) subunits of the heterotetrameric protein succinate dehydrogenase (mitochondrial complex II) are important causes of inherited and apparently sporadic paragangliomas. In an effort to further investigate the role of these genes in malignant sympathetic paragangliomas and adrenal pheochromocytomas, we screened a series of tumors for mutations in SDHB and SDHD. Mutation testing was performed on DNA extracted from formalin-fixed, paraffin-embedded tumors and associated normal tissues by polymerase chain reaction amplification and direct sequencing of the coding regions and intron-exon junctions of the SDHB and SDHD genes. Among 16 malignant paragangliomas with proven metastases, 6 (38%) had mutations in SDHB (2 nonsense, 1 splice site, 1 insertion causing a frameshift, and 2 presumably deleterious missense mutations). Probable deleterious SDHB variants were also detected in 5 (45%) of 11 paragangliomas without known metastatic disease (1 splice site, 1 deletion causing a frameshift, and 3 missense changes). In 12 malignant pheochromocytomas, 1 SDHD and no SDHB mutations were identified. The identical SDHB mutation was detected in DNA extracted from accompanying normal tissue for each of the 10 cases on which this analysis was performed. An excess of SDHB mutations in paragangliomas versus pheochromocytomas was found, with no difference in the frequency of mutations in malignant versus benign paragangliomas. The disparate mutational spectra in malignant paragangliomas and pheochromocytomas may reflect differences in underlying tumor biology.

To assess whether the type of surgical approach to the sella (sublabial transseptal vs transnasal) affects surgical outcome among patients with Cushing disease.Both procedures were performed at our institution from January 1, 1995, through January 31, 2003. From a total of 106 patients with Cushing disease who had had surgery, we identified 42 adults undergoing an initial surgery, with microadenoma (1 cm) determined by magnetic resonance imaging and a minimal follow-up of 3 months.We identified 21 patients (4 male, 17 female) for sublabial transseptal transsphenoidal microsurgery. Mean+/-SD age was 45.0+/-12.9 years (range, 27.0-69.0 years); median duration of symptoms was 2.5 years (range, 1.5-7.5 years). Median follow-up was 1.0 year (range, 0.3-11.0 years). We identified another 21 patients (5 male, 16 female) for endoscopic transsphenoidal microsurgery whose mean+/-SD age was 43.8+/-14.1 years (range, 19.0-70.0 years); median duration of symptoms was 2.4 years (range, 0.2-6.0 years). Median follow-up was 2.5 years (range, 0.3-8.7 years). Complications (cerebrospinal fluid leak and transient diabetes insipidus) and cure (86% initial cure; 76% relapse-included cure) were equivalent between the 2 procedures. However, the endoscopic approach was associated with shorter anesthesia time, less blood loss, and shorter hospital stays.The endoscopic transnasal surgical approach led to shorter total anesthesia time, less blood loss, and shorter hospital stay when compared with the sublabial transseptal approach. However, we found no difference between the 2 surgical procedures with respect to cure or complications, suggesting that outcome is more closely related to the experience of the operating team.

Cushing’s syndrome (CS), due to multiple etiologies, is a disorder associated with the ravages of cortisol excess. The purpose of this review article is to provide a historical synopsis of surgery for CS, review a recent 10-year period of operative management at a tertiary care facility, and to outline a practical approach to diagnosis and management. From 1996 to 2005, 298 patients underwent 322 operative procedures for CS at Mayo Clinic, Rochester, Minnesota. A retrospective chart review was carried out. Data was gathered regarding demographics, preoperative assessment, procedures performed, and outcomes. Data are presented as counts and percentages. Five-year survival rates were calculated where applicable by the Kaplan-Meier method. Statistical analysis was carried out with SAS, version 9 (SAS Institute, Inc., Cary, NC). Two-hundred thirty-one patients (78%) had ACTH-dependent CS and 67 patients (22%) had ACTH-independent CS. One-hundred ninety-six patients (66%) had pituitary-dependent CS and 35 patients (12%) had ectopic ACTH syndrome. Fifty-four patients (18%) had cortisol-secreting adenomas, 10 patients (3%) had cortisol-producing adrenocortical carcinomas, and 1% had other causes. Cure rates for first time pituitary operations (transsphenoidal, sublabial, and endonasal) were 80% and 55% for reoperations. Most benign adrenal processes could be managed laparoscopically. Five-year survival rates (all causes) were 90%, 51%, and 23% for adrenocortical adenomas, ectopic ACTH syndrome, and adrenocortical carcinomas, respectively. Surgery for CS is highly successful for pituitary-dependent CS and most ACTH-independent adrenal causes. Bilateral total adrenalectomy can also provide effective palliation from the ravages of hypercortisolism in patients with ectopic ACTH syndrome and for those who have failed transsphenoidal surgery. Unfortunately, to date, adrenocortical carcinomas are rarely cured. Future successes with this disease will likely depend on a better understanding of tumor biology, more effective adjuvant therapies and earlier detection. Clearly, IPSS, advances in cross-sectional imaging, along with developments in transsphenoidal and laparoscopic surgery, have had the greatest impact on today’s management of the complex patient with CS.

Management of patients with bilateral adrenal masses and corticotropin (ACTH)-independent Cushing syndrome (CS) or subclinical CS is problematic. We report our experience with adrenal venous sampling (AVS) in the evaluation of 10 patients with bilateral masses who had ACTH-independent CS or subclinical CS. Ten patients (9 women, 1 man, mean age 56.4 years) with bilateral adrenal masses and ACTH-independent CS (n = 3) or subclinical CS (n = 7) underwent AVS. Autonomous cortisol secretion was documented in all cases with suppressed serum ACTH concentrations and lack of cortisol suppression with dexamethasone administration. Adrenal venous sampling was performed on the second day of dexamethasone administration. Cortisol and epinephrine levels were measured from each adrenal vein (AV) and from a peripheral vein (PV). Mean (± SD) maximal diameter of the adrenal masses on computed tomography was 3.3 ± 1.3 cm (range: 1.2–6.0 cm). Successful catheterization was confirmed with AV:PV epinephrine gradients. A cortisol AV:PV gradient >6.5 was consistent with a cortisol-secreting adenoma in 11 adrenal glands; 5 patients had clinically important bilateral autonomous cortisol hypersecretion, 3 had bilateral cortisol-secreting adenomas, and 2 had ACTH-independent macronodular adrenal hyperplasia. Adrenal venous sampling-guided adrenalectomy was completed in all 10 patients—2 patients had total bilateral adrenalectomy and 2 others had subtotal bilateral adrenalectomy. During a mean follow-up of 36.1 months (range: 0.7–123 months), CS or clinically important cortisol secretory autonomy did not recur. Adrenal venous sampling contributed to the localization of autonomous hypercortisolism in the setting of ACTH-independent CS or subclinical CS in patients with bilateral adrenal masses.

Context: The definitive diagnosis of Cushing’s syndrome (CS) in the setting of mild disease, as well as exclusion of CS in the setting of conditions that might mimic this clinical entity (pseudo-Cushing’s syndrome), continues to present a significant challenge to the clinician. Objective: The aim of the study was to review characteristics of the combined dexamethasone-suppressed CRH stimulation test in patients evaluated at an academic center for the possibility of mild CS. Design, Patients, and Methods: We conducted a retrospective review of 66 patients. A total of 51 patients underwent final statistical analysis: 21 (41%) had Cushing’s disease, and 30 were considered to have pseudo-CS based on the clinical scenario, comorbidities, and follow-up. Sensitivity, specificity, and diagnostic accuracy of cortisol and ACTH levels for the diagnosis of Cushing’s disease were calculated at 1 min before, and 15, 30, 45, and 60 min after CRH administration. Diagnostic cutoffs for each parameter were determined by minimizing the absolute difference between sensitivity and specificity. Diagnostic accuracy was characterized by the area under the receiver operating characteristic curve, determined using the trapezoid rule. Results: The highest diagnostic accuracy was provided by the serum ACTH level at 15 min post-CRH, in which the area under the receiver operating characteristic curve was 99.7%, and a cutoff of more than 27pg/ml(5.9pmol/liter)providedasensitivityof95%andspecificity of 97% for the diagnosis of CS. A 15-min post-CRH cortisol greater than 2.5 g/dl (70 nmol/liter) provided a sensitivity and specificity of 90 and 90%, respectively. Conclusions: Our results differ from previous studies because our data suggest that when using the combined dexamethasone-suppressed CRH stimulation test, a 15-min post-CRH ACTH value greater than 27 pg/ml (5.9 pmol/liter) had the highest diagnostic accuracy for the detection of CS. However, the sensitivity and specificity for this test were not statistically different from the sensitivity and specificity of other tests, such as those measuring post-CRH stimulated ACTH levels or post-CRH cortisol levels at other time points. Therefore, clinicians should be cautious about interpretation of suppression and stimulation tests in the diverse population of patients with hypercortisolism. (J Clin Endocrinol Metab 92: 2972–2976, 2007)

Great strides have been made in our understanding of the pathophysiology of primary aldosteronism syndrome since Conn's description of the clinical presentation of a patient with an aldosterone-producing adenoma (APA) more than 50 years ago. It is now recognized that the APA is just one of the seven subtypes of primary aldosteronism. APA and bilateral idiopathic hyperaldosteronism (IHA) are the most common subtypes of primary aldosteronism. Although most clinicians had thought primary aldosteronism to be a rare form of hypertension for more than three decades, it is now recognized to be the most common form of secondary hypertension. Using the plasma aldosterone to plasma renin activity ratio as a case-finding test, followed by aldosterone suppression confirmatory testing, has resulted in much higher prevalence estimates of 5-13% of all patients with hypertension. In addition, there has been a new recognition of the aldosterone-specific cardiovascular morbidity and mortality associated with aldosterone excess. Although thought to be daunting and complex in the past, the diagnostic approach to primary aldosteronism is straightforward and can be considered in three phases: case-finding tests, confirmatory tests and subtype evaluation tests. Patients with hypertension and hypokalaemia (regardless of presumed cause), treatment-resistant hypertension (three antihypertensive drugs and poor control), severe hypertension (>or= 160 mmHg systolic or >or= 100 mmHg diastolic), hypertension and an incidental adrenal mass, onset of hypertension at a young age or patients being evaluated for other forms of secondary hypertension should undergo screening for primary aldosteronism. In patients with suspected primary aldosteronism, screening can be accomplished by measuring a morning (preferably between 0800 and 1000 h) ambulatory paired random plasma aldosterone concentration (PAC) and plasma renin activity (PRA). An increased PAC:PRA ratio is not diagnostic by itself, and primary aldosteronism must be confirmed by demonstrating inappropriate aldosterone secretion. Aldosterone suppression testing can be performed with orally administered sodium chloride and measurement of urinary aldosterone or with intravenous sodium chloride loading and measurement of PAC. Unilateral adrenalectomy in patients with APA or unilateral adrenal hyperplasia results in normalization of hypokalaemia in all these patients; hypertension is improved in all and is cured in approximately 30-60% of them. In bilateral adrenal forms of primary aldosteronism, unilateral or bilateral adrenalectomy seldom corrects the hypertension and they should be treated medically with a mineralocorticoid receptor antagonist.

We investigate the potential of using arbitrarily placed wireless transceivers to increase the probability of maintaining a communication link in an electrically harsh environment. Specifically, we adapt a well-known matrix-based array optimization technique to the case when the transmitting elements exist in a complex environment and the receiver is not in the far-field of the array. Study of array performance in a non-ideal setting represents an important step in determining the feasibility of using this optimization technique for ad hoc wireless arrays within a building. Measures of array performance consist of median values for the directivity or gain, the total power at the receiver location, and the power per transmitter. The simulation results include array performance in the presence of a lossy dielectric corner to study the effects of building floors and walls. Our results show the median of the optimized directivity or gain for the frequencies of interest with simple boundaries is within 3 dB of that for the optimized configuration in free space

A 68-year-old woman is incidentally found to have a left adrenal mass, 2.8 cm in diameter, on abdominal computed tomography that was ordered to evaluate right lower abdominal discomfort (which has since resolved). Her medical history is notable only for hypertension that has been well controlled with hydrochlorothiazide, at a dose of 25 mg daily. She reports no sweating, palpitations, headache, weight gain, or proximal muscle weakness. Her physical examination is unremarkable. How should she be evaluated?

Patients with multiple endocrine neoplasia type 1 (MEN1) are commonly evaluated for clinical manifestations of this syndrome with the rationale that early diagnosis and adequate treatment will result in improved survival and quality of life. Thymic and bronchial carcinoid tumours are uncommon but important manifestations of MEN1. Current practice guidelines recommend evaluation with computed tomography or magnetic resonance imaging scan of the chest every 1-2 years to detect these neoplasms. However, the certainty that patients will be better off (increased survival or quality of life) as a result of this case detection strategy is based on evidence at moderate-high risk of bias that yields only imprecise results of indirect relevance to these patients. In order to improve the care that patients with MEN1 receive, co-ordinated efforts from different stakeholders are required so that large, prospective, multicentre studies evaluating patient important outcomes are carried out.

We discuss the use of a metric based on the amplitude variation of a channel in the signal bandwidth to predict whether or not a digital wireless communication test system receiver will be able to demodulate a test signal. This metric is compared to another method consisting of the correlation calculated across the channel. A logistic regression analysis is used to provide a normalized assessment of the effectiveness of each metric as a predictive tool. We show that both metrics provide similar predictive capabilities, with the peak-to-minimum being significantly easier to calculate. Keywords—coherence bandwidth; correlation bandwidth; over-the-air measurement; reverberation chamber; wireless channel; wireless communication test system.

A technique to facilitate blood sampling from the right adrenal vein is described. Between May 2012 and February 2015, 148 adrenal vein sampling (AVS) procedures were attempted. In 72 procedures, a simple 5-F end-hole catheter was employed. In 76, a coaxial guide wire technique was used when blood could not be aspirated, whereby a 0.018-inch guide wire was passed through the catheter and into a branch of the right adrenal vein and the sample was drawn around the wire by using a side-arm adaptor. Successful sampling was achieved in 71 of the 72 catheter-only procedures (98.6%) and in 75 of the 76 coaxial wire-assisted procedures (98.7%). This simple technique may eliminate the need for multiple catheter exchanges during AVS.

The discovery ofSDHDas a pheochromocytoma/paraganglioma susceptibility gene was the prismatic event that led to all of the subsequent work highlighting the key roles played by mitochondria in the pathogenesis of these tumors and other solid cancers. Alterations in the function of tricarboxylic acid cycle enzymes can cause accumulation of intermediate substrates and subsequent changes in cell metabolism, activation of the angiogenic pathway, increased reactive oxygen species production, DNA hypermethylation, and modification of the tumor microenvironment favoring tumor growth and aggressiveness. The elucidation of these tumorigenic mechanisms should lead to novel therapeutic targets for the treatment of the most aggressive forms of pheochromocytoma/paraganglioma.

The clinical features of thymic carcinoid (TC) and bronchial carcinoid (BC) tumors as part of multiple endocrine neoplasia type 1 (MEN1) have been rarely described and their importance in clinical practice is debated. The objective of this study was to describe the clinical presentation and outcome of this uncommon manifestation of MEN1 in a tertiary care center setting. We present the clinical features of patients with MEN1 and either TC or BC evaluated at the Mayo Clinic from 1977 to 2013. A total of 348 patients with MEN1 were evaluated and the prevalence of TC was 2.0% (n = 7) and of BC 4.9% (n = 17). The majority of the patients with BC were men (61%) diagnosed on routine screening (77%) and BC was not the confirmed cause of death in any patient. In contrast, TC patients were all men and during follow-up 43% died due to TC complications. We conclude that TC and BC tumors are uncommon, but important components of MEN1. BC were most commonly diagnosed during routine screening and associated with an indolent course. TC were predominantly seen in men and associated with a more aggressive behavior.

Previous testing has shown that measuring a device's susceptibility to a radiated, broadband signal can present a different set of challenges than those faced when testing with a narrow-band signal. Decisions ranging from choosing a measurement facility to defining the measurement of the radiated electric field to defining when a DUT has failed can all have an impact on the final test results. In previous publications we've outlined these challenges via the use of experiments involving cable communications equipment and its susceptibility (or lack thereof) to radiated LTE signals. Here, we continue with those experiments, but shift the focus to proposing solutions to these questions. We discuss these solutions in a general sense, with hopes that they will encourage discussion in the community.

This paper discusses several wireless coexistence test methods in-practice and proposed for industry standards such as ANSI C63.27 The test methods include conducted and radiated setups, and utilize a range of technologies at various levels of sophistication, including consumer electronics, laboratory grade test equipment, and anechoic test chambers. Some key parameters associated with the testing environments are outlined, and the benefits and limitations of the different test methods are discussed. Finally, some ideas on research needed to reconcile the outputs from the various tests are explored.

OBJECTIVE. The aim of this study was to review our institutional experience managing pheochromocytomas and paragangliomas in children.METHODS. A retrospective chart review of the Mayo Clinic database from 1975 to 2005 identified 30 patients RESULTS. There were 12 patients with pheochromocytomas and 18 with paragangliomas. The most common presenting symptoms were hypertension (64%), palpitation (53%), headache (47%), and mass-related effects (30%). Nine patients (30%) had a genetic mutation or documented family history of pheochromocytoma or paraganglioma. Fourteen patients (47%) had malignant disease, whereas 16 (53%) had benign disease. Logistic analysis showed that statistically significant risk factors for malignancy were (1) paraganglioma, (2) apparently sporadic, as opposed to familial, pheochromocytoma or paraganglioma, and (3) tumor size of >6 cm. Surgical resection was performed for 28 patients (93%), with perioperative mortality and major morbidity rates of 0% and 10%, respectively. Resection achieved symptomatic relief for 25 patients (83%). All patients with benign disease appeared cured after resection. For patients with malignant disease, the 5- and 10-year disease-specific survival rates were 78% and 31%, respectively, and the mean survival time was 157 ± 32 months.CONCLUSIONS. The incidence of malignant pheochromocytoma/paraganglioma was high in children (47%), particularly those with apparently sporadic disease, paraganglioma, and tumor diameters of >6 cm. Patients with a known genetic mutation or familial pheochromocytoma/paraganglioma were more likely to achieve resection with negative microscopic margins and had improved disease-specific mortality rates. Surgical resection remains the treatment of choice for pheochromocytoma and paraganglioma.

Paragangliomas are rare tumors that arise from extra-adrenal paraganglia. The effective diagnosis and management of the paraganglioma patient involves the close collaboration of endocrinologists, endocrine surgeons, anesthesiologists, geneticists, laboratory specialists, radiologists, oncologists, and pathologists. Paragangliomas are diagnosed in the following clinical settings: signs and symptoms related to catecholamine hypersecretion, mass effect symptoms (e.g., with head and neck paragangliomas), incidental finding on imaging, or family screening for hereditary paraganglioma. Paragangliomas that hypersecrete catecholamines may cause signs and symptoms identical to those in patients with hyperfunctioning adrenal pheochromocytoma. When a catecholamine-secreting tumor is suspected in a patient because of paroxysmal symptoms, biochemical documentation of catecholamine and fractionated metanephrine hypersecretion should precede any form of imaging study. Catecholamine-secreting paragangliomas are found where chromaffin tissue is located (e.g., along the para-aortic sympathetic chain, or within the organs of Zuckerkandl at the origin of the inferior mesenteric artery, the wall of the urinary bladder, and the sympathetic chain in the neck or mediastinum). As many as 50% of para-gangliomas are hereditary and may be associated with familial paraganglioma, neurofibromatosis Type 1, von Hippel-Lindau disease, the Carney triad, and, rarely, with multiple endocrine neoplasia Type 2. Genetic testing should be considered in all patients with paraganglioma. The treatment of choice for paraganglioma is surgical resection; most tumors are benign and can be excised totally. Following surgical cure, annual biochemical testing assesses for metastatic disease, tumor recurrence or delayed appearance of multiple primary tumors.

Although Turner syndrome is not uncommon, studies of the pituitary in this condition are few. We undertook a histochemical and immunohistochemical study of four cases. As expected, "gonadal failure cells" were seen, but without recognizable gonadotroph hyperplasia. No gonadotroph adenomas were encountered. Instead, three silent corticotroph microadenomas were seen; their etiology remains unexplained. The question of whether the simultaneous occurrence of Turner syndrome and silent corticotroph adenoma is causal or incidental cannot be answered on the basis of the study of our material. Because these two diseases are rare, an etiologic association has to be considered. For example, it is possible that (a) protracted stimulation of gonadotrophs leads to transdifferentiation to corticotrophs, a hypothesis supported by the fact that normal and neoplastic gonadotrophs can contain ACTH and that some corticotroph adenomas produce LH and/or alpha subunit, (b) corticotrophs develop gonadotropin-releasing hormone (GnRH) receptors and undergo neoplastic transformation when exposed to continuous elevation of GnRH, FSH, and/or LH levels, and (c) the genetic defect in Turner syndrome promotes the formation of corticotroph adenomas.

Study design This is a retrospective study consisting of medical records review and evaluation of pertinent radiographs. Objectives In this study, complications and outcomes are reviewed in a series of HIV-positive patients undergoing spinal surgery. Surgery was performed for conditions that were unrelated to HIV infection. Methods From the period 1996 to 2000, we identified 10 seropositive patients who underwent spinal procedures for conditions that did not arise as a complication of HIV infection. A retrospective review was done, which included inpatient and out patient records. Results A total of 6 women and 5 men who were HIV-positive underwent spinal surgery during the time period reviewed. Surgery was performed for a variety of conditions, including lumbar disc herniaition, degenerative disc disease, cervical disc herniation, spinal fractures, and Arnold-Chiari malformation. The mean CD4 count was 279 cells/mm3 before surgery. All patients had at least 6 months of conservative management before surgery, except in the case of those who had spinal fractures. Two patients sustained postoperative complications: 1 patient developed a superficial wound infection, which was successfully treated with antibiotics, and 1 patient experienced prolonged fever (7 days) after surgery, which resolved without a clear diagnosis. All patients were improved after surgery (mean follow-up, 29.3 months) Conclusions Many physicians have held a nihilistic approach, when it comes to the treatment of HIV-positive persons. However, our results in this small series of patients suggest that spinal surgery may be appropriate and can be performed with acceptable outcomes in selected patients.

Background The aim of this study was to determine the effect of adrenal venous sampling (AVS) on the management of patients with primary aldosteronism. Methods From September 1990 through October 2003, 203 patients with primary aldosteronism (mean age, 53 years; range, 17-80; 163 men) were selected prospectively for AVS on the basis of degree of aldosterone excess, age, desire for surgical treatment, and computed tomographic (CT) findings. Results Both adrenal veins were catheterized in 194 patients (95.6%). Notable among the 110 patients (56.7%) with unilateral aldosterone hypersecretion were 24 (41.4%) of 58 patients with normal adrenal CT findings, 24 (51.1%) of 47 with unilateral micronodule (≤10 mm) apparent on CT (7 had unilateral aldosterone hypersecretion from the contralateral adrenal), 21 (65.6%) of 32 with unilateral macronodule (>10 mm) apparent on CT (1 had unilateral aldosterone hypersecretion from the contralateral adrenal), 16 (48.5%) of 33 with bilateral micronodules, and 2 (33%) of 6 with bilateral macronodules. Conclusions On the basis of CT findings alone, 42 patients (21.7%) would have been incorrectly excluded as candidates for adrenalectomy, and 48 (24.7%) might have had unnecessary or inappropriate adrenalectomy. AVS is an essential diagnostic step in most patients to distinguish between unilateral and bilateral adrenal aldosterone hypersecretion.

Pheochromocytoma is a rare, life-threatening condition. Using a modeling technique, we studied the economic implications of detection strategies for pheochromocytoma (third-party payer perspective). The diagnostic efficacy of biochemical tests was based on Mayo Clinic Rochester data. In all hypothetical algorithms, positive biochemical tests were followed by abdominal computerized tomography and, if negative, metaiodobenzylguanidine scintigraphy. In each hypothetical algorithm, imaging would be indicated after positive biochemical testing as follows: algorithm A, fractionated plasma metanephrine measurements above the laboratory reference range; or algorithm B, abnormal measurements of 24-h urinary total metanephrines or catecholamines. In algorithm C, subjects with fractions of plasma metanephrine at or above 0.5 nmol/liter or normetanephrine at or above 1.80 nmol/liter would undergo imaging, whereas those with values between the reference range and these cutoffs would undergo 24-h urinary measurements (total metanephrines and fractionated catecholamines) and be imaged if positive. We determined that, if 100,000 hypertensive patients (including 500 patients with pheochromocytoma) were tested, algorithm A (measurement of fractionated plasma metanephrines alone) would detect 489 pheochromocytoma patients at a cost of 56.6 million dollars, whereas B (24-h urinary measurements) would detect 457 pheochromocytoma patients for 39.5 million dollars, and C (combination of measurements of fractionated plasma metanephrines and urines) would detect 478 patients for 28.6 million dollars. None of the screening strategies for pheochromocytoma described are affordable if implemented on a routine basis in extremely low-risk patients. However, algorithm C may be the least costly, and at a reasonable level of sensitivity, for subjects in whom the suspicion of disease is moderate.

Background Adrenal tumors that secrete androgens exclusively are extraordinarily rare. The aim of this study was to characterize patients with pure androgen-secreting adrenal tumors. Methods A retrospective chart review from January 1946 through November 2002 identified 11 female patients with pure androgen-secreting adrenal tumors. Results The mean age was 23.4 years (range, 1-52). The most common presenting symptoms were hirsutism, acne, and clitoral enlargement. Elevated 17-ketosteroids were found in seven of nine tested patients. Computed tomogram, ultrasound, or both localized tumors in six of seven patients. All tumors were surgically resected, one laparoscopically, all without complications. Five of the 11 tumors were malignant. Mean weight and mean maximal diameter for benign and malignant tumors were 44 g and 4.2 cm and 232 g and 9.8 cm, respectively. Mean hospital stay was 8.5 days, with excess androgen production resolved in all patients. Recurrence and disease-related death occurred in only one patient who had pulmonary metastases at diagnosis. The remaining patients had no recurrence of tumor at mean follow-up of 11.7 years (range, 0.5-32 years). Conclusions Pure androgen-producing tumors are extremely rare. Approximately 50% are benign, and surgical resection provides excellent treatment if the tumors are not metastatic at the time of diagnosis.