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I whole-body bone scan was performed for an adult male patient after postradioactive iodine ablation of thyroid carcinoma. Besides the small thyroid remnants in the neck region, an incidental detection of left inguinal hernia was made in the scan, which was later confirmed by clinical examination. Despite the large size of the hernia, the patient was unaware of the condition. It can be concluded that, similar to other imaging procedures, incidental detection of unrelated clinical problems is possible in I scan also, and such early diagnosis prevents further complications that the patient may develop in the future.

Osteosarcoma metastases frequently occur in the lungs or the skeleton. Bone scans play an important role in disease staging by identifying other skip areas of skeletal involvement as well as extraosseous metastases. We report a case of aggressive osteosarcoma, with bone metastases and extraosseous areas of involvement in the lungs, distant lymph nodes, and peritoneal and subcutaneous metastasis seen in a preoperative Tc-99m methylene diphosphonate bone scan. These findings were confirmed with histology and correlative cross-sectional imaging.

Pancreatic involvement by metastasis from other primaries is rare and accounts for approximately 2% to 4% of pancreatic tumors. In this article, we describe FDG-avid pancreatic involvement in a patient with diagnosis of breast cancer. We conclude that FDG PET can be a convenient noninvasive method of early detection of recurrence and in monitoring metastatic disease during follow-up in such patients. A positive FDG PET warrants histopathologic correlation for appropriate treatment.

Erdheim-Chester disease is a rare non-Langerhans cell histiocytosis characterized by progressive histiocytic proliferation with multiorgan involvement, typically of the kidney, skin, brain, and lung, and less frequently, the heart and retro-orbital tissue. Fluorine-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) plays an important role in the management of this disease. It has been reported that FDG PET imaging allows accurate evaluation of the extent of the disease at baseline, as well as assessment of response to any specific therapy. In this case, a 57-year-old Chinese man presented with functional decline and a urinary tract infection. He had a prior history of xanthogranulomas of bilateral canthal masses. On imaging, he was found to have left hydronephrosis, diffuse urothelial thickening, increased density of the perinephric fat, mural thickening of the descending aorta and soft tissue masses along the posterior wall of the right atrium extending into the region of the interatrial septum and involving the right atrioventricular groove. Histopathology revealed retroperitoneal fibrosis. An IV contrast-enhanced FDG PET scan showed increased activity in a previously unidentified brain stem mass and the shafts of bilateral femora. Varying levels of FDG uptake were seen in the other lesions.

A 2-month-old infant had jaundice that began 3 days after birth. The clinical features were suggestive of biliary obstruction. Tc-99m mebrofenin hepatobiliary imaging confirmed the diagnosis of spontaneous perforation of the common bile duct, and surgical intervention resulted in progressive recovery.

A 30-year-old man had severe left anterior knee pain after a trivial injury. A three-phase bone scan diagnosed this condition to be reflex sympathetic dystrophy, which was subsequently confirmed by sympathetic blockade.

Insular carcinoma of the thyroid appears to represent an entity situated morphologically and biologically in an intermediate position between the well-differentiated and undifferentiated (anaplastic) tumors. The retention of I-131 concentrating ability by this variant, unlike anaplastic, is very encouraging and amenable to detection and therapy by radioiodine after initial aggressive surgery. A 46-year-old man with a histologic label of anaplastic thyroid carcinoma has had an unusually prolonged disease-free survival and histopathologic review confirmed insular carcinoma. Postoperative radioiodine evaluation revealed avid concentration of tracer in the thyroid bed. Thus, it is possible to ablate with radioiodine. The insular carcinoma should be considered as a distinct clinicopathologic entity and widespread awareness of this variant of tumor may help pathologists, surgeons, and nuclear medicine practitioners to aggressively treat the condition after initial diagnosis.

A nine-year-old child was referred for a routine renal dynamic study to detect a renal and/or renovascular cause for hypertension. Tc-99m DTPA renography accidentally discovered and correctly localized a pheochromocytoma.

Six preoperative and five postoperative hepatobiliary scans in children having cystic dilatation of the biliary tract were analyzed. The preoperative hepatobiliary scans revealed three distinct patterns. The type 1 pattern showed, in early scans, good hepatic uptake of radioactivity, and photon deficient area(s) around the porta hepatis or in the subhepatic region. These area(s) showed progressive accumulation of radio activity in the delayed scans. The type 2 pattern revealed poor hepatic uptake, nonvisualization of major biliary channels, and photon deficient area(s) in the porta hepatis or subhepatic region which persisted throughout the study. Preoperatively, it was possible to diagnose cystic dilatation of biliary tract in cases that showed type 1 and type 2 patterns. No preoperative diagnosis was possible when the scans showed a type 3 pattern. Analysis of results revealed a correct pre-operative diagnostic rate of 83.3% for the cystic dilatation of biliary tract. It was also possible to provide correct functional information regarding the patency of the bile outflow tract in all 11 cases, both pre- and postoperatively, with a diagnostic rate of 100%. On the basis of the overall accuracy of results obtained in this series, hepatobiliary scintigraphy is strongly advocated in suspected cases of cystic dilatation of the biliary tract for the initial diagnosis and for the assessment of the status of the bilioenteric bypass postoperatively.