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Biomedical subjects

N W Thompson

Publications and source records attributed to N W Thompson.

At least 145 records · Page 8Linked to original sources

Recurrent medullary carcinoma of the thyroid demonstrated by thallium-201 scintigraphy.

Thallium-201 scintigraphy has been used in the evaluation of thyroid neoplasms, but uptake in recurrent or persistent medullary thyroid cancer has not been reported. We present two cases where focal 201TI activity localized superior mediastinal recurrences which were subsequently resected. Postoperative 201TI scans in both cases showed elimination of the focal uptake seen before surgery, as well as return of previously elevated serum calcitonin levels to normal. Scanning with 201TI may be useful in the preoperative localization of recurrent medullary thyroid cancer.

Adult↗

Hyperparathyroidism and gastroenteropancreatic hormone levels.

The diagnosis of multiple endocrine neoplasia (MEN) in patients with presumed hyperparathyroidism has important ramifications for patient management especially since as many as 20% of patients with hyperparathyroidism may have associated MEN. Gut hormone levels were measured before and after surgery in 28 patients who underwent resection of a single parathyroid adenoma for biochemical or clinical evidence of hyperparathyroidism. The mean serum calcium level was 11.9 +/- 0.2 mg/dl before surgery and 9.3 +/- 0.3 mg/dl after surgery (p less than 0.001). Two or more hormone levels were elevated in 32% of patients before surgery and 21% after surgery. The same hormone abnormalities (pancreatic polypeptide [PP] and gastrin) occurred 56% of the time. Of elevated preoperative levels of PP, 91% were in the normal range after surgery. In patients with elevated preoperative PP levels, the postoperative level of PP decreased by an average of 64% of the preoperative level. In 27% of patients the level increased more than double the preoperative value. In two of four patients with high levels of PP after surgery the serum calcium level failed to fall. Of 18 patients whose PP levels fell, 17 had a fall in serum calcium levels. Of six patients whose PP levels rose, four had a significant fall in calcium levels. There was no correlation between the absolute levels or the decremental change of calcium and the change in PP. Several abnormalities in gut hormone secretion occur in patients with primary hyperparathyroidism and a parathyroid adenoma. An elevated serum level of PP does not signify MEN syndrome and must be reevaluated after resection of the parathyroid adenoma. Failure of adequate tumor resection is attended by persistent elevation of serum calcium and PP levels.

Adult↗

Limitations of 131I-MIBG scintigraphy in locating pheochromocytomas.

131I-metaiodobenzylguanidine (131I-MIBG) scintigraphy for the location of pheochromocytomas has proved to be a major advance in patient management. In combination with computerized tomographic scanning, nearly all pheochromocytomas can be located before surgery and invasive investigations are now indicated only in exceptional cases. However, there are still lessons to be learned concerning the optimal administration and interpretation of 131I-MIBG scintigraphy. With careful attention to detail and an awareness of isotope distribution, false positive studies should be extremely rare. While the incidence of false negative studies is uncommon, these certainly occur. A patient with sporadic bilateral adrenal medullary hyperplasia, bilateral pheochromocytomas, and additional benign pheochromocytomas arising in paraganglia tissue anterior to the abdominal aorta is presented. The right adrenal pheochromocytoma was not identified on 131I-MIBG imaging. We conclude that even with current locating techniques, the traditional surgical approach to pheochromocytoma should not be abandoned. This involves transabdominal exploration of both adrenal glands and careful examination of all possible sites of extra-adrenal pheochromocytomas.

3-Iodobenzylguanidine↗

Hemorrhage into a hepatic adenoma and type Ia glycogen storage disease: a case report and review of the literature.

Older patients with type I glycogen storage disease (GSD) develop hepatic adenomas that may undergo malignant transformation. Despite their similarity to oral contraceptive-related hepatic tumors, only one previous report has even mentioned hemorrhage in GSD-related hepatic tumors. We recently followed a 20-year-old patient with type Ia GSD and a 10 cm focal defect in the left lobe of the liver; angiography suggested that this was a benign adenoma. At 22 years of age, after an acute symptomatic episode, repeat studies (ultrasonography and angiography) revealed a 2 cm increase in diameter of the hepatic mass. Imminent tumor rupture was of grave concern; thus the patient was admitted to the hospital and given 2 weeks of constant glucose administration by central venous line in the hope of improving her metabolic abnormalities. After resolution of the coagulopathy and metabolic disorders, the patient safely underwent surgical enucleation of the tumor. Pathologic examination of the tumor revealed that the patient had indeed hemorrhaged into a typical hepatic adenoma that had focuses of hepatocellular dysplasia. She has done well without evidence of tumor recurrence for 3 years since the operation. We conclude that hemorrhage and malignant transformation are potential complications of GSD-related hepatic adenomas. This conclusion underscores the importance of following these patients closely as they age. Nocturnal nasogastric feeding should be considered in the hope of preventing a tumor or inducing regression. Acute symptomatic attacks should be evaluated promptly for possible tumor hemorrhage.

Adenoma↗

Cardiac paragangliomas. A clinicopathologic and immunohistochemical study of four cases.

Cardiac paragangliomas are extremely rare neoplasms. Four surgically resected tumors were examined by immunohistochemistry and electron microscopy. The patients ranged in age from 18 to 36 years. All patients had hypertension and elevated urine catecholamine levels. Three tumors were located on the posterior left atrium, and one tumor was located in the interventricular groove at the aortic root. The tumors ranged in size from 5 to 7 cm, and they displayed a prominent Zellballen pattern without significant necrosis or mitosis. The tumors were mostly unencapsulated and infiltrated adjacent cardiac tissue in two cases. Immunoperoxidase staining showed that all tumors were positive for chromogranin and neuron-specific enolase. Three tumors were positive for methionine enkephalin. Positive staining for S-100 protein was seen in the sustentacular cells of all tumors but was negative in chromaffin cells. All tumors were negative for insulin, glucagon, gastrin, vasoactive intestinal polypeptide, somatostatin, adrenocorticotropic hormone, calcitonin, serotonin, pancreatic polypeptide, and rat atrial peptide. Ultrastructural studies of all four tumors showed moderate numbers of predominantly norepinephrine-type granules and a few epinephrine-type granules. These results show that cardiac paragangliomas are commonly found in close proximity to the left atrium and have immunohistochemical and ultrastructural features similar to other paragangliomas.

Adolescent↗

Familial extra-adrenal pheochromocytoma. A new syndrome.

Pheochromocytomas in the same anatomic site, the right renal hilum, occurred in a family over three successive generations. For two patients in the latter two generations, scintigraphy with iodine 131-tagged metaiodobenzylguanidine (MIBG) showed tumors only in the region of the right renal hilum, thus indicating that they were primary lesions. At surgery, except for lymph node metastases noted microscopically in one patient, tumors were found only near the right renal hilum. The adrenal glands seemed normal on inspection, palpation, and computed tomography. In another family, a mother and son had primary pheochromocytomas arising from the urinary bladder. We suggest that primary extra-adrenal pheochromocytoma is a syndrome in which specific genetic abnormalities determine sites of tumor development.

Adolescent↗

Surgical treatment of cardiac pheochromocytomas.

The development at our institution of the radiopharmaceutical 131-I-metaiodobenzylguanidine has permitted for the first time scintigraphic localization of pheochromocytomas. By the use of this scan in combination with contrast-enhanced computed tomography, intrapericardial pheochromocytomas have been demonstrated in eight patients at our hospital during the past 2 years. Four of these patients have been operated upon by us, and each was found to have a pheochromocytoma arising from the heart (left atrium in three and interventricular groove at the aortic root in one). While in one patient it was possible to "shell" the tumor away from the left atrial wall without cardiopulmonary bypass, in the remaining patients, bypass and cardioplegia were required to resect the pheochromocytomas without inducing life-threatening intraoperative hypertension and cardiac arrhythmias. One patient required coronary artery reconstruction and two, excision of the posterior left atrial wall with pericardial replacement. One of these latter two patients died intraoperatively of uncontrollable hemorrhage. The three remaining patients are well and normotensive after more than 1 year of follow-up. Cardiac pheochromocytomas should not be approached as typical posterior mediastinal tumors, or as they are in the abdomen, with the expectation that they will "shell away" from contiguous structures. Cardiopulmonary bypass should be available, and resection of involved myocardium may be necessary for complete removal.

3-Iodobenzylguanidine↗

Extrapancreatic gastrinomas.

From 1978 to 1984, six patients (four men and two women) with functioning extrapancreatic gastrinomas were treated at the University of Michigan Medical Center. In all but one patient, who was known to have a liver metastasis, selective portal and peripheral venous sampling was performed to localize the site(s) of increased gastrin levels. Serum levels of carboxy (C) and amino (N) terminal gastrin moieties were measured before surgery with region-specific antisera and N/C ratios were calculated. All patients underwent operative exploration and successful resection of all gastrinomas present including a single large liver metastasis in one case. The C-terminal gastrin level was elevated in all cases and the N/C ratios were well below 1.0 (greater than 1 is consistent with malignancy and metastases) in all but the one patient with a liver metastasis. All patients have remained clinically free of tumor and have had normal basal and secretin-stimulated gastrin levels for as long as 5 years after operation. Three of the patients had undergone previous total gastrectomies and had done well apart from persistent hypergastrinemia before resection of the tumor. Two patients have not undergone any type of gastric operation. Appropriately selected patients with Zollinger-Ellison syndrome, particularly those with extrapancreatic primary lesions, may be candidates for a curative resection.

Adult↗

Pancreatic polypeptide-producing tumors. Silent lesions of the pancreas?

Eight patients with pancreatic polypeptide (PP)-producing islet cell tumors and one patient with pseudo-PP-producing tumors were examined. Their age range was 20 to 74 years. Clinical features included abdominal pain in four patients, weight loss in four patients, diarrhea in two patients, gastrointestinal bleeding in two patients, and jaundice in one patient. The range of the basal serum level of PP was 394 to 35,100 pg/mL. In two patients the PP-producing tumors were associated with multiple endocrine neoplasia. Two patients had diffuse hepatic metastases at the time of diagnosis and four patients had disease limited to the pancreas. Pancreaticoduodenectomy and 80% pancreatectomy were performed in four and two patients, respectively. Immunohistochemical staining was positive for PP and neuron-specific enolase in all cases and was negative for other peptides except in one specimen with microadenomatosis. Patients who underwent curative resection are asymptomatic with normal serum levels of PP.

Abdomen↗

Efficacy of preoperative biliary tract decompression in patients with obstructive jaundice.

Fifty consecutive matched patients with benign or malignant biliary tract obstruction were compared to determine the efficacy of preoperative percutaneous biliary drainage (PBD). Twenty-five patients underwent PBD for an average of nine days before operation; 25 patients underwent percutaneous transhepatic cholangiography ( PTHC ) followed immediately by operation. Serum bilirubin levels before PTHC were 16.5 +/- 7.6 mg/dL and 14.9 +/- 7.6 mg/dL in PBD and non-PBD groups, respectively. Serum bilirubin levels decreased to 6.5 +/- 6.2 mg/dL preoperatively in patients having PBD. One week after operation, bilirubin levels were 4.2 +/- 4.3 mg/dL and 9.0 +/- 5.2 mg/dL in the PBD and non-PBD groups, respectively. Major morbidity (sepsis, abscess, renal failure, or bleeding) occurred in two patients (8%) having PBD and in 13 patients (52%) without PBD. One patient (4%) with PBD, and five patients (20%) without PBD, died. The mean hospital stay was shorter for the PBD group. Preoperative PBD reduces operative mortality and morbidity and results in a more rapid resolution of hyperbilirubinemia during the postoperative period.

Biliary Tract Surgical Procedures↗

Substance P in the localization of a carcinoid tumor.

A 55-year-old woman with an ovarian carcinoid presented with intermittent facial and cervical flushing for 10 years, watery diarrhea for 4 years, and abdominal pain without hepatomegaly. Markedly elevated systemic venous and arterial serotonin levels (830 ng/ml; nl = 50-200 ng/ml) were found. The highest serotonin levels were observed in the superior vena caval system, but serotonin as a marker for tumor localization was inaccurate and led to an unproductive neck exploration. The histological pattern of this tumor contained purely insular elements. No hepatic or nodal metastases were identified and the lesion was unilateral. Substance P levels were elevated in the venous drainage of the left ovary and in retrospect correctly localized the ovarian tumor. This peptide may prove to be another carcinoid tumor marker in addition to serotonin and 5-hydroxyindoleacetic acid. Substance P may also be an important mediator of symptoms in patients with carcinoid syndrome.

Carcinoid Tumor↗

Scintigraphic localization of adrenal lesions in primary aldosteronism.

Dexamethasone suppression adrenal cortical scintiscanning was performed in 87 patients with primary aldosteronism. Fifty patients had adrenal cortical adenomas and 37 had bilateral adrenal hyperplasia. The diagnosis of adrenal cortical adenoma was confirmed by surgery in 49 of 50, and bilateral adrenal hyperplasia was confirmed by adrenal vein aldosterone sampling in 33 and at operation in four. Dexamethasone suppression adrenal scintigraphy correctly identified the lesion(s) in 82 of the 87 patients. There were three false-negative and two false-positive adrenal cortical scintiscanning results. Computed tomography was performed in 33 patients and correctly identified 14 of 23 patients with adrenal cortical adenomas and two of 10 patients with bilateral adrenal hyperplasia and bilateral enlarged adrenals, whereas the remaining eight were considered to have normal findings. These data indicate that, when properly performed, adrenal cortical scintigraphy is an accurate and efficacious modality for the localization of adrenal cortical adenomas and in the differentiation of adrenal cortical adenoma from bilateral adrenal hyperplasia in primary aldosteronism.

Adenoma↗

Cystic neuroendocrine neoplasms of the pancreas and liver.

Four cases involving cystic endocrine neoplasms of the pancreas and liver are reported. Because of their rich collateral blood supply, islet cell tumors of the pancreas, even if large in size, rarely undergo central or cystic degeneration. However, failure to appreciate that a small percentage of these neoplasms may mimic benign pancreatic pseudocysts by their clinical and radiological appearance can lead to inappropriate surgical therapy. Ultrasound, computerized tomography, and/or angiography are rarely helpful in distinguishing between benign and neoplastic cysts. The definitive diagnosis can be made with assurance only by obtaining a generous biopsy of the cyst wall or any intracystic excrescences for histologic examination. Functional cystic tumors of the pancreas or liver should be excised totally whenever possible, and efforts should be made to remove as much of the tumor mass as possible even when a curative resection cannot be accomplished. Internal drainage may be acceptable as palliation for large, unresectable tumors.

Adenoma, Islet Cell↗