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Metastatic lesions occur in up to 36% of patients with pheochromocytoma. Currently there is no way to reliably detect or predict which patients are at risk for metastatic pheochromocytoma. Thus, the discovery of biomarkers that could distinguish patients with benign disease from those with metastatic disease would be of great clinical value. Using surface-enhanced laser desorption ionization protein chips combined with high-resolution mass spectrometry, we tested the hypothesis that pheochromocytoma pathologic states can be reflected as biomarker information within the low molecular weight (LMW) region of the serum proteome. LMW protein profiles were generated from the serum of 67 pheochromocytoma patients from four institutions and analyzed by two different bioinformatics approaches employing pattern recognition algorithms to determine if the LMW component of the circulatory proteome contains potentially useful discriminatory information. Both approaches were able to identify combinations of LMW molecules which could distinguish all metastatic from all benign pheochromocytomas in a separate blinded validation set. In conclusion, for this study set low molecular mass biomarker information correlated with pheochromocytoma pathologic state using blinded validation. If confirmed in larger validation studies, efforts to identify the underlying diagnostic molecules by sequencing would be warranted. In the future, measurement of these biomarkers could be potentially used to improve the ability to identify patients with metastatic disease.

Pheochromocytomas in von Hippel-Lindau (VHL) syndrome produce exclusively norepinephrine, whereas those in multiple endocrine neoplasia type 2 (MEN 2) produce epinephrine. This study examined the pathways activated in VHL-associated pheochromocytomas by comparing gene expression profiles in VHL and MEN 2 tumors in relationship to profiles in sporadic norepinephrine- and epinephrine-producing tumors. Larger and more distinct differences in gene expression among hereditary than sporadic tumors indicated the importance of the underlying mutation to gene expression profiles. Many of the genes over-expressed in VHL compared with MEN 2 tumors were clearly linked to the hypoxia-driven angiogenic pathways that are activated in VHL-associated tumorigenesis. Such genes included those for the glucose transporter, vascular endothelial growth factor (VEGF), placental growth factor, angiopoietin 2, tie-1, VEGF receptor 2 and its coreceptor, neuropilin-1. Other up-regulated genes, such as connective tissue growth factor, cysteine-rich 61, matrix metalloproteinase 1, vascular endothelial cadherin, tenascin C, stanniocalcin 1, and cyclooxygenases 1 and 2 are known to be involved in VEGF-regulated angiogenesis. Shared differences in expression of subsets of genes in norepinephrine- versus epinephrine-producing hereditary and sporadic pheochromocytomas indicated other differences in gene expression that may underlie the biochemical phenotype. Over-expression of the hypoxia-inducible transcription factor, HIF-2alpha, in norepinephrine-predominant sporadic and VHL tumors compared with epinephrine-producing tumors indicates that expression of this gene depends on the noradrenergic biochemical phenotype. The findings fit with the known expression of HIF-2alpha in norepinephrine-producing cells of the sympathetic nervous system and might explain both the development and noradrenergic biochemical phenotype of pheochromocytomas in VHL syndrome.

Objective: Minimally invasive approaches to the management of renal tumors are being studied intensively in urology. Herein, we describe the use of multiple organ-sparing techniques for the management of tumors in a patient with von Hippel Lindau disease (VHL)., Materials and Methods: A 42 year-old woman with VHL underwent a right partial adrenalectomy and a left renal radiofrequency ablation (RFA) of two renal tumors., Results: A 2.2 cm solitary right adrenal pheochromocytoma was resected using a transperitoneal approach. A retroperitoneal approach to the left kidney was performed and RFA of the two renal tumors completed using sonographic guidance. On the 5-month follow-up CT scan, there was no evidence of residual adrenal tumors and both renal lesions lacked contrast enhancement. No complications occurred during the post-operative recovery., Conclusions: Multiple organ-ablative laparoscopic procedures may be performed in a single sitting. Laparoscopic partial adrenalectomy is an effective technique in patients with bilateral tumors or a familial syndrome predisposing to multiple adrenal tumors. Further study of renal RFA is required to assess the long-term durability of the procedure.

This study examined the mechanisms linking different biochemical and clinical phenotypes of pheochromocytoma in multiple endocrine neoplasia type 2 (MEN 2) and von Hippel-Lindau (VHL) syndrome to underlying differences in the expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis, and of phenylethanolamine N-methyltransferase (PNMT), the enzyme that converts norepinephrine to epinephrine. Signs and symptoms of pheochromocytoma, plasma catecholamines and metanephrines, and tumor cell neurochemistry and expression of TH and PNMT were examined in 19 MEN 2 patients and 30 VHL patients with adrenal pheochromocytomas. MEN 2 patients were more symptomatic and had a higher incidence of hypertension (mainly paroxysmal) and higher plasma concentrations of metanephrines, but paradoxically lower total plasma concentrations of catecholamines, than VHL patients. MEN 2 patients all had elevated plasma concentrations of the epinephrine metabolite, metanephrine, whereas VHL patients showed specific increases in the norepinephrine metabolite, normetanephrine. The above differences in clinical presentation were largely explained by lower total tissue contents of catecholamines and expression of TH and negligible stores of epinephrine and expression of PNMT in pheochromocytomas from VHL than from MEN 2 patients. Thus, mutation-dependent differences in the expression of genes controlling catecholamine synthesis represent molecular mechanisms linking the underlying mutation to differences in clinical presentation of pheochromocytoma in patients with MEN 2 and the VHL syndrome.

Pheochromocytoma is a rare but important tumor of chromaffin cells that is frequently considered in the evaluation of hypertension, arrhythmias, or panic disorder and in the follow-up of patients with particular genetic diseases. This report provides an update about the genetics, neurochemical diagnosis, localization by imaging, and surgical management of pheochromocytoma. Specific mutations of the RET proto-oncogene cause familial predisposition to pheochromocytoma in multiple endocrine neoplasia type II, and mutations in the von Hippel-Lindau tumor suppressor gene cause familial disposition to pheochromocytoma in von Hippel-Lindau disease. Recent findings demonstrating extraordinarily high sensitivity of plasma levels of metanephrines for detecting pheochromocytoma have led to an algorithm for clinical diagnostic steps. Nuclear imaging approaches, such as(123) I-metaiodobenzylguanidine scintigraphy and 6-[(18) F]fluorodopamine positron emission tomography, enhance both diagnosis and localization of the tumor, as described in an algorithm for patients with positive biochemical test results. Since pheochromocytoma is often benign, surgical resection by laparoscopic adrenalectomy can be curative. Areas requiring further work include determining appropriate follow-up of patients with familial pheochromocytoma, elucidating the bases for phenotypic differences, improving both specificity and sensitivity of biochemical tests, optimizing cost-effectiveness of diagnostic imaging, and testing the risk for tumor recurrence after partial adrenalectomy.

Most adrenal tumors are found incidentally and appear as small solitary nodules on abdominal imaging. Occasionally, work-up demonstrates multifocal or bilateral adrenal tumors. Certain patients are predisposed to multiple lesions, such as those with hereditary forms of pheochromocytoma as seen in von Hippel-Lindau disease, multiple endocrine neoplasia type II, and von Recklinghausen's disease. Partial rather than total adrenalectomy should be considered for these patients in an attempt to preserve endogenous adrenocortical function. Partial adrenalectomy has also been used to resect other types of adrenal tumors, especially in patients with a solitary adrenal gland. A discussion of the indications for partial adrenalectomy and of the surgical technique follows.

von Hippel-Lindau disease (VHL) is an autosomal dominant familial syndrome that predisposes to the formation of tumors in multiple organ systems, including adrenal and extra-adrenal pheochromocytomas. However, fewer than 30% of VHL families develop pheochromocytomas. In recent years, this clinical heterogeneity has been correlated with missense mutations. The VHL patient requires vigilant, lifelong biochemical and radiographic screening for pheochromocytoma. Half of VHL pheochromocytomas present bilaterally, and there is a high incidence of recurrence after surgery. Because of the morbidity of bilateral total adrenalectomy with subsequent steroid replacement therapy, the recent therapeutic trend has been toward observation and minimally invasive adrenal-sparing procedures.

In primary hyperaldosteronism, discriminating bilateral adrenal hyperplasia (BAH) from an aldosterone-producing adenoma (APA) is important because adrenalectomy, which is usually curative in APA, is seldom effective in BAH. We analyzed the results from our most recent 7-yr series to evaluate the predictive value of preoperative noninvasive tests compared with adrenal vein sampling (AVS). Forty-eight patients with hypertensive hyperaldosteronism underwent bedside testing, computed tomography (CT) imaging, and AVS. Those in whom the results of AVS indicated APA underwent adrenalectomy. Twelve (30%) and 14 (34%) of 41 patients with APA had paradoxical falls with ambulation in plasma aldosterone concentration (PAC) and 18-hydroxycorticosterone (18-OH-B), respectively. Twenty-nine (70%) and 26 (65%) APA patients had a rise in PAC and 18-OH-B, respectively, as did all 8 BAH patients. Significant identifiers of BAH were supine PAC values less than 15 ng/dL (P: = 0.04), an increase greater than 60% (P: = 0.02) in PAC with ambulation, and supine 18-OH-B values less than 60 ng/dL (P: = 0.04). CT imaging alone was not predictive for BAH or APA. In our population, patients with a positive bedside test result (e.g. a fall in PAC and/or 18-OH-B) and a unilateral adrenal nodule on CT (10 of 41 patients) could have proceeded directly to adrenalectomy for APA. However, a positive bedside test result with a negative CT or a negative bedside test result regardless of CT findings required AVS to confirm the diagnosis and site of disease.

Purpose: Patients with von Hippel-Lindau disease are predisposed to multiple bilateral adrenal pheochromocytoma. In these patients partial adrenalectomy may preserve adrenocortical function and avoid the morbidity associated with medical adrenal replacement. We report our experience with such cases., Materials and Methods: Laparoscopic partial adrenalectomy was performed in patients with von Hippel-Lindau disease and pheochromocytoma when there was evidence of normal adrenocortical tissue on preoperative imaging or intraoperative examination. Suture ligature or a harmonic scalpel was used to excise the tumors, leaving a 2 to 3 mm. margin of normal tissue., Results: Two patients underwent laparoscopic partial adrenalectomy and 1 laparoscopic bilateral partial adrenalectomy with preservation of normal adrenocortical tissue. Seven pheochromocytomas were removed. Laparoscopic ultrasound was essential for localizing 2 pheochromocytomas that were not visualized by the camera. Median operative time was 324 minutes, blood loss 100 cc and parenteral narcotic requirement 22 mg. morphine equivalents. No patient required hydrocortisone replacement. There has been no pheochromocytoma recurrence during short-term followup., Conclusions: Laparoscopic partial adrenalectomy is technically feasible in patients with a hereditary form of pheochromocytoma, and may preserve adrenocortical function. Laparoscopic ultrasound was necessary to identify 2 of the 7 pheochromocytomas removed.

Purpose: Families with von Hippel-Lindau disease have variable risk of pheochromocytoma. Patients with von Hippel-Lindau disease and pheochromocytoma identified by screening can have no characteristic signs or symptoms. Families with von Hippel-Lindau disease were screened and followed to describe the natural history of von Hippel-Lindau pheochromocytoma, and to correlate these findings with von Hippel-Lindau germline mutation., Materials and Methods: Between 1988 and 1997, 246 individuals with von Hippel-Lindau disease were identified (von Hippel-Lindau group). Between August 1990 and June 1997, 26 consecutive patients with sporadic pheochromocytoma were evaluated (sporadic group)., Results: A total of 64 patients with von Hippel-Lindau disease had manifestations of pheochromocytoma, including 33 newly diagnosed during screening at the National Institutes of Health and 31 previously treated (93 adrenal and 13 extra-adrenal pheochromocytomas). Germline von Hippel-Lindau gene missense mutation was associated with extra-adrenal pheochromocytoma, younger age at presentation and the only patient with metastases. Of the 33 newly diagnosed patients with von Hippel-Lindau disease 4 had pheochromocytoma 2 times (37 pheochromocytomas) during followup. Of these pheochromocytomas 35% (13 of 37) were associated with no symptoms, normal blood pressure and normal catecholamine testing. Comparison of urinary catecholamines in the von Hippel-Lindau and sporadic groups demonstrated increased epinephrine, metanephrines and vanillylmandelic acid in the sporadic group. Analysis of urinary catecholamine excretion in the von Hippel-Lindau and sporadic groups together demonstrated a correlation between tumor size, and urinary metanephrines, vanillylmandelic acid, norepinephrine, epinephrine and dopamine. In 12 patients without signs or symptoms of pheochromocytoma 17 newly diagnosed pheochromocytomas were followed for a median of 34.5 months without morbidity. Median tumor doubling time was 17 months., Conclusions: Von Hippel-Lindau gene missense mutation correlated with the risk of pheochromocytoma in patients with von Hippel-Lindau disease. These findings support a von Hippel-Lindau disease clinical classification, wherein some families are at high risk for manifestations of pheochromocytoma. Von Hippel-Lindau disease pheochromocytomas identified by screening were smaller and less functional than sporadic pheochromocytomas.

Pheochromocytoma is a catecholamine-producing tumor of the sympathetic nervous system. Signs and symptoms are generally related to catecholamine excess; these include hypertension, sweating, palpitatione, headaches, and anxiety attacks. Abdominal imaging and 24-h urine collection for catecholamines are usually be sufficient for diagnosis. Catecholamine blockade with phenoxybenzamine and metyrosine generally ameliorates symptoms and is necessary to prevent hypertensive crisis during surgery. Standard treatment is laparoscopic adrenalectomy, although partial adrenalectomy is gaining enthusiastic support in familial forms of pheochromocytoma. Pheochromocytomas have been estimated to be present in approximately 0.3% of patients undergoing evaluation for secondary causes of hypertension [41]. Pheochromocytomas are usually curable if diagnosed and treated properly, but they can be fatal if they are not diagnosed or are managed inappropriately. Autopsy series suggest that many pheochromocytomas are not clinically suspected and that the undiagnosed tumor can be associated with morbid consequences [42].

Purpose: In patients with von Hippel-Lindau disease multiple bilateral adrenal pheochromocytoma can develop, which has traditionally been treated with adrenalectomy. Partial adrenalectomy can preserve normal adrenal function and avoid the morbidity associated with medical adrenal replacement. We demonstrate whether adrenal function could be preserved by partial adrenalectomy in patients with von Hippel-Lindau disease., Materials and Methods: From 1995 to 1998, 13 consecutive von Hippel-Lindau disease patients with pheochromocytoma underwent 14 partial and 6 complete unilateral adrenalectomies. Function of residual normal adrenal and recurrence of adrenal pheochromocytoma were determined at followup., Results: Of the patients 2 had undergone unilateral adrenalectomy and 1 had undergone complete and partial adrenalectomy previously. Following surgery residual normal adrenal tissue consisted of 1 partial adrenal in 3 patients, bilateral partial adrenal in 5, partial and complete adrenal gland in 1, 1 complete adrenal gland in 3 and no adrenal tissue in 1. Three patients with residual adrenal tissue were placed on medical adrenal replacement until adrenocorticotropic hormone stimulation testing demonstrated adrenocortical function. In 2 patients 1 adrenal and 2 extra-adrenal new pheochromocytomas developed 11 and 152 months, respectively, after partial adrenalectomy. No morbidity related to pheochromocytoma was observed during followup., Conclusions: Partial adrenalectomy can preserve adrenal function in patients with a hereditary form of pheochromocytoma.

Objectives: Adrenalectomy is the mainstay of treatment for adrenal tumors. A variety of surgical approaches to the adrenal gland have been described. We studied the feasibility of laparoscopic adrenalectomy (LA), compared laparoscopic with open adrenalectomy (OA), and studied the hemodynamic changes in patients with pheochromocytoma., Methods: Our early experience with 20 consecutive LAs is compared with a contemporaneous, matched control cohort of 20 patients who underwent OA via a flank or subcostal incision. LA was performed via a transperitoneal approach, following a standardized surgical technique., Results: LA was successfully completed in 18 of 20 cases. Average operating time in the first 5 cases was 261 minutes, but, with further experience, a significant decrease in operative time was seen in the last cohort of 4 patients (155 minutes) (P = 0.0018). There was no significant difference in operative time or degree of blood loss between LA and OA groups. Patients who underwent LA required lower doses of postoperative parenteral narcotics (P = 0.0169), had a shorter hospital stay (mean 3.2 days) (P < 0.0001), and had a shorter convalescent period (mean 3.1 weeks) (P < 0.0001). Complications in the laparoscopic group (chronic port site pain in 1 patient, intra-abdominal fluid collection in another) occurred in the 2 patients who required open conversion. These 2 patients had large adrenal tumors (9 and 7 cm in diameter, respectively). LA resulted in similar hemodynamic changes as OA in patients with pheochromocytoma., Conclusions: LA is a safe and effective approach in most patients with adrenal pathology. Benefits include excellent operative exposure and visualization, less postoperative pain, shorter hospital stay and convalescent period, and improved cosmetic result. Pheochromocytoma is not a contraindication to LA. Patients with large adrenal tumors (larger than 6 cm), evidence of venous involvement, or invasion into surrounding tissue should be approached cautiously.

Extra-adrenal myelolipomas are rare, benign tumors composed of hematopoietic and adipose elements. Although these tumors can cause local symptoms or hemorrhage, they are generally asymptomatic. However, when discovered intraoperatively, they pose a diagnostic dilemma to the urologic surgeon. We present a case of perirenal extra-adrenal myelolipoma discovered intraoperatively in a patient with von Hippel-Lindau disease undergoing partial nephrectomy.

Adrenalectomy can be successfully and safely carried out with a laparoscopic technique, using standard instrumentation via a transperitoneal approach. We describe five tasks to be completed by the surgeon: (a) generation of pneumoperitoneum and port placement, (b) exposure of the adrenal gland, (c) dissection of the adrenal gland, (d) clipping of the adrenal vein, and (e) removal of the adrenal gland and fascial closure of port sites. Each step is described in detail for right and left adrenalectomy. Laparoscopic adrenalectomy is advocated on the same grounds as other laparoscopic procedure, namely, decreased postoperative pain and ileus, a better cosmetic result, decreased hospital stay, and a shorter convalescent period. Some other advantages of the laparoscopic technique are: minimal extent of dissection and excellent visibility and exposure of the adrenal gland.

Despite recommended preoperative preparation with alpha-adrenergic blockers, severe hemodynamic instability may occur during operations to resect pheochromocytoma. We combined the alpha-blocker phenoxybenzamine with the tyrosine hydroxylase inhibitor metyrosine in an attempt to better manage the hypertension of patients with pheochromocytoma undergoing surgical resection. This report reviews the cases of 25 consecutive patients undergoing surgery for known intra-abdominal pheochromocytoma. Each patient had elevated serum or urine levels of catecholamines or their metabolites. Nineteen patients were prepared before operation with phenoxybenzamine and metyrosine and six patients were given phenoxybenzamine alone. There were no significant differences in maximum, minimum, or mean blood pressure before or after tumor resection between patients who received metyrosine and those who did not. However careful review suggested that those who received metyrosine had more severe disease as judged by biochemical criteria. Study of selected patients matched for age and severity of disease suggested that the intraoperative blood pressure management of patients prepared with phenoxybenzamine and metyrosine was facilitated. In addition metyrosine-prepared patients lost less blood and required less volume replacement during surgery than did non-metyrosine-prepared patients. There were no apparent differences in postoperative fluid requirements. Although the study is not a prospective randomized trial, a retrospective review of patients managed with the combination of phenoxybenzamine and metyrosine suggests that surgery to resect pheochromocytoma can be better performed with both drugs than with phenoxybenzamine alone. The combination regimen appears to result in better blood pressure control, less blood loss, and the need for less intraoperative fluid replacement than does the traditional method of single-agent alpha-adrenergic blockade.