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Biomedical subjects

N W Thompson

Publications and source records attributed to N W Thompson.

At least 19 recordsLinked to original sources

Surgical approach to insulinomas. Assessing the need for preoperative localization.

The purpose of this study was to examine our experience with the diagnosis, surgical approach, and outcomes of surgery for organic hyperinsulinemia in the era of transhepatic venous sampling. During the period from 1978 to 1991, 50 patients were evaluated and treated for hyperinsulinemia at the University of Michigan Medical Center, all of whom underwent preoperative localization. Forty-one patients (82%) had solitary, benign tumors; four (8%) had either multiple tumors or islet cell dysplasia; and five (10%) had metastatic disease. Forty-seven patients underwent laparotomy, and the source of the hyperinsulinemia was found in all patients. In three patients (6%) preoperative localization did not accurately locate the tumor due to technical difficulties with the completion of the studies. Overall, computed tomography localized nine (26%) of 35 tumors. Angiography accurately localized 18 (44%) of 41 tumors. Transhepatic venous sampling localized 34 (94%) of 36 tumors, and was essential to successful surgical treatment in 15 patients. Compared with angiography, transhepatic venous sampling was a more accurate method of localization and should be performed in all patients in whom computed tomography and visceral angiography do not clearly identify the site of disease. Preoperative localization plays a critical role in the surgical treatment of patients with organic hyperinsulinemia and eliminates the need for blind pancreatic resection.

Adult

Fine-needle aspiration biopsy causing peritoneal seeding of a carcinoid tumor.

A rare complication of fine-needle aspiration biopsy (FNA) is needle tract seeding. Peritoneal seeding from FNA in the clinical setting is rarely reported. To our knowledge, this is the first case of peritoneal seeding of a neuroendocrine carcinoid tumor as a result of FNA. Peritoneal contamination and tumor seeding can occur with FNA and they probably do occur more often than is recognized clinically. Therefore, we caution against the use of FNA in the assessment of potentially curable intra-abdominal tumors, and recommend that this technique be used only when a cytological diagnosis is required before initiation of palliative therapy.

Adenoma, Islet Cell

Analysis of gastrinomas by immunohistochemistry and in situ hybridization histochemistry.

Gastrinomas from 25 patients were examined by immunohistochemistry (IHC) and in situ hybridization histochemistry (ISH). Most patients (84%) presented with the Zollinger-Ellison syndrome. Six had multiple endocrine neoplasia type I (MEN-I). Twelve patients (48%) had duodenal primaries and 11 of 12 of these had metastases to regional lymph nodes and/or liver in spite of the small sizes of the primary tumors (mean size of 0.9 cm). Five patients had pancreatic gastrinomas and eight patients had metastatic tumor in regional lymph nodes or liver at surgery but a primary was not found. IHC and ISH analyses showed that all cases were positive for gastrin protein and 24 of 25 (96%) expressed gastrin mRNA that was easily detected in formalin-fixed, paraffin-embedded tissue sections. Both benign and malignant tumors expressed alpha subunit of human chorionic gonadotropin protein (alpha-HCG). However, only malignant gastrinomas (29%) expressed adrenocorticotropic hormone protein or proopiomelanocortin (POMC) mRNA. ISH and Northern hybridization analysis revealed that chromogranin A mRNA was the most common member of the chromogranin/secretogranin (Cg/Sg) family which was expressed in both benign and malignant gastrinomas. These results indicate that duodenal gastrinomas are common in both sporadic and MEN-1-associated cases, and small duodenal primaries may be associated with extensive regional lymph node and liver metastases. Expression of ACTH/POMC protein and mRNA was consistently associated only with malignant gastrinomas while gastrin protein, gastrin mRNA and Cgs/Sgs mRNAs were readily detected in both benign and malignant gastrinomas.

Adrenocorticotropic Hormone

Surgical treatment of the endocrine pancreas and Zollinger-Ellison syndrome in the MEN 1 syndrome.

Islet cell neoplasia is a frequent occurrence in multiple endocrine neoplasia type 1 (MEN 1). Sixteen of 27 patients with MEN 1 developed functioning endocrine pancreatic tumor syndromes. Eleven of the 16 developed Zollinger-Ellison syndrome and each was evaluated by a combination of computed tomography and hepatic angiography to exclude hepatic metastasis and percutaneous transhepatic catheterization to localize the tumor. Seven of the 11 patients were found to have duodenal gastrinomas with multiple duodenal tumors in three patients. Four of the 11 patients had only pancreatic gastrinomas. In addition to the gastrinomas, other types of islet tumors in the pancreatic body or tail were found in nine of the 11 patients. None of the patients had hepatic metastases. Seven of the 11 patients were treated by distal pancreatectomy and since 1986 all patients have had duodenotomies as part of the surgical exploration. Postsurgical evaluation ranging from three months to 14 years indicates that 10 of 11 patients have normal basal gastrin levels. We conclude that duodenal gastrinomas are common in MEN 1 and can be managed successfully by appropriate operative intervention.

Adenoma, Islet Cell

Adrenal scintigraphy of well-differentiated (functioning) adrenocortical carcinomas: potential surgical pitfalls.

Adrenal scintigraphy with 131I-6 beta-iodomethylnorcholesterol (NP-59) has been widely used to evaluate adrenal cortical tumors during the past 20 years. Unilateral visualization on the side of an adrenal tumor has been considered diagnostic of a benign adrenocortical adenoma in the patient with Cushing's syndrome. Bilateral nonvisualization of the adrenal glands in the presence of Cushing's syndrome is considered diagnostic of adrenocortical carcinoma (ACC). ACCs characteristically are unable to incorporate enough NP-59 to be visualized on NP-59 adrenal scintigraphy. Two patients with well-differentiated cortisol-secreting ACCs, in which the primary tumor or subsequent metastases demonstrated intense uptake (visualization) on NP-59 scans are reported here. As a result of these findings on NP-59 adrenal scintigraphy, the lesions were initially misinterpreted to represent benign disease. In each patient the operative approach selected, based on the interpretation of the NP-59 scan, was inappropriate for the management of the respective adrenal neoplasm or its metastasis. A review of the literature reveals 16 other cases of either ACC or their metastases that were visualized with adrenal scintigraphy. Ninety percent of these cases were associated with adrenocortical hormone hypersecretion. It is concluded that in the presence of Cushing's syndrome or another adrenocortical hormone excess state, unilateral visualization of an adrenal tumor on NP-59 scintigraphy cannot be interpreted to represent uniformly benign disease.

Adosterol

PET scanning with hydroxyephedrine: an approach to the localization of pheochromocytoma.

Pheochromocytomas are potentially curable causes of hypertension. These tumors are currently located by functional imaging with meta-iodobenzylguanidine (MIBG), usually labeled with 131I, or anatomic imaging (computed tomography, magnetic resonance). Hydroxyephedrine (HED) is a newly developed radiotracer that concentrates in adrenergic nerve terminals. When HED is labeled with 11C, its distribution can be mapped in vivo using PET. The purposes of this investigation were to characterize the uptake of 11C-HED in pheochromocytoma and to determine the feasibility and advantages of utilizing this compound as a tumor imaging agent. Ten patients with known or suspected pheochromocytoma were studied. Each patient underwent PET scanning with 11C-HED and conventional scintigraphy with MIBG. Pheochromocytomas were localized by PET scanning in 9 of the 10 patients. Image quality was excellent and superior to that obtained from planar and tomographic MIBG studies. The uptake of 11C-HED into pheochromocytomas was rapid; tumors were evident within 5 min following intravenous injection. All lesions within the field of view that were identified by MIBG scintigraphy were readily apparent. PET scanning with 11C-HED localizes pheochromocytoma using a specifically designed radiotracer and advanced imaging technology. The method has promise for locating the more elusive tumors.

3-Iodobenzylguanidine

Clinical significance of the large adrenal mass.

Current clinical teaching indicates that large (greater than 5 cm in diameter) adrenal masses are often malignant. In a retrospective analysis of patients studied between 1977 and 1988 with computed tomography (CT), adrenal scintigraphy, and when available, magnetic resonance imaging (MRI) 45 were found to have adrenal masses greater than 5 cm (range 5-19 cm) in diameter. Thirty were benign (16 phaeochromocytomas, six adrenocortical adenomas, four adrenal cysts, two myelolipomas, an adrenal hematoma and a ganglioneuroma). Of 15 malignant masses, there were seven adrenocortical carcinomas, five adrenal metastases and three adrenal lymphomas. With the exception of the adrenal myelolipomas, cysts, and the ganglioneuroma neither CT nor MRI demonstrated sufficient diagnostic specificity to distinguish benign from malignant lesions. Functional scintigraphy with 131I-6-beta-iodomethyl-19-norcholesterol for suspected adrenocortical lesions and 131I-metaiodobenzylguanidine for suspected phaeochromocytomas frequently provided useful information.

19-Iodocholesterol

Papillary carcinoma of the thyroid with mucoepidermoid features.

The significance and differential diagnoses of signet-ring cells found in the fine-needle aspirate of metastatic mucoepidermoid carcinoma from the thyroid are reported and discussed. The primary tumor occurred in a 35-year-old man, who had a history of neck irradiation during his childhood. Despite postoperative treatment with 60 Gy external radiation and 1,200 mCi 131I, the patient has at present--12 years after the initial operation--progressive disease with local recurrence in the neck as well as lung metastases.

Adult

Primary hyperparathyroidism due to solitary adenoma. A comparative multicentre study of early and long-term results of different surgical regimens.

Surgical regimens for treatment of solitary parathyroid adenoma were compared in a multicentre study in five departments of surgery in the United States and Europe. Three hundred and twenty-five patients fulfilled the inclusion criteria. Eight years after the operation 272 patients (84%) were available for follow-up investigation. Severe postoperative hypocalcaemia (less than 2.00 mmol) was significantly more common after bilateral than unilateral exploration (p less than 0.001), and in women (p less than 0.01). Neither age nor preoperative serum calcium concentration was related to the severity of postoperative hypocalcaemia. At follow-up, 96% of the patients who had had unilateral, and 89% of those who had had Bilateral exploration had remained normocalcaemic without further treatment. Of the patients who had had incisional biopsies of normal glands 8% had hypercalcaemia and 8% had hypocalcaemia. Of patients operated on without a biopsy being taken or who had had one whole normal gland removed 1% were hypercalcaemic and 4% were hypocalcaemic. Early and late hypocalcaemia are reduced by atraumatic handling of the normal parathyroid gland without increasing the risk of persistent or recurrent hypercalcaemia.

Adenoma

Metastatic parathyroid carcinoma: dilemmas in management.

The incidence of parathyroid carcinoma in patients surgically treated for primary hyperparathyroidism at the University of Michigan Hospital was 0.4% during an 18-year period. The courses of the five patients with metastatic disease are described. Histologic reevaluation and assessment of the DNA ploidy pattern were performed in each case. Localization studies preceded all reexplorations. The number of operative procedures in each patient ranged from two to 10. Two patients are living with recurrent disease and one has been disease free for 42 months. Two patients died after 2 and 12 years, respectively. Three patients had aneuploid tumors; one had a diploid tumor. One patient had both aneuploid and diploid cell populations. Dilemmas in diagnosis, localization, and medical and surgical management were encountered in patients with metastatic carcinoma. The chosen treatment should be evaluated individually in each case because of the variability in aggressiveness of this malignancy. Surgical resection proved most effective in some of these patients for both local and distant recurrences. Bisphosphonates and gallium nitrate have been reported to be effective in controlling hypercalcemia. Only the former had some effect in one of our patients.

Adult

Clinical significance of the solitary functioning adrenal gland.

To assess the compensatory functional and anatomic changes in the remaining adrenal cortex after unilateral adrenalectomy or in the unaffected adrenal in patients with unilateral adrenal destruction by neoplasm, 17 patients with a single, functioning adrenal gland and normal indices of adrenocortical function, nine after adrenalectomy and eight with a unilateral, destructive adrenal lesion were studied with 131I-6 beta-iodomethyl-19-norcholesterol (NP-59) scintigraphy and computed tomography. Adrenal masses with a mean (+/- s.d.) diameter of 2.8 +/- 1.0 cm; (range 1-4 cm; 95% confidence interval (Cl), 2.5-3.1 cm) were identified by computed tomography in seven of nine patients in the remaining adrenal cortex at variable times (6.1 +/- 5.9 y; range 0.5-19 y) after unilateral adrenalectomy. Mean (+/- s.e.m.) NP-59 uptake was elevated (p less than 0.01) in both adrenalectomy and adrenal destruction groups, mean uptake (+/- s.e.m.) was 0.32% +/- 0.04% administered dose (95% Cl, 0.24%-0.4% administered dose) as compared to normal (0.16% +/- 0.05% administered dose, 95% Cl, 0.06%-0.26% administered dose). The remaining adrenal cortex may be anatomically abnormal after unilateral adrenalectomy and demonstrate compensatory, increased NP-59 uptake in the presence of overall, normal adrenocortical function.

Adosterol

Pheochromocytoma of the urinary bladder.

A case of pheochromocytoma of the bladder involving a ureteral orifice is presented, with a review of the literature. We discuss general management principles of bladder pheochromocytoma and factors specific to the management of our case, which allowed complete removal of the benign tumor while preserving bladder and ureteral function. Imaging modalities for localizing extraadrenal pheochromocytomas are reviewed.

Adult

Current diagnosis and treatment of pheochromocytoma in children. Experience with 22 consecutive tumors in 14 patients.

Pheochromocytoma is a rare tumor of childhood. In comparison with adults with pheochromocytomas, children have a higher incidence of bilaterality, familial association, and extra-adrenal location. Fourteen children with 22 tumors were treated during the period 1970 through 1988. Children presented at a mean age of 13 years. Most children (10 of 14) presented with sustained hypertension. The majority of tumors were located with a combination of computed tomography and iodine 131 metaiodobenzylguanidine scanning. Eight adrenal and six extra-adrenal tumors were resected. Four children underwent bilateral adrenalectomy. Follow-up data are available on 9 of the 14 children. All of these patients remain normotensive without medication. Preoperative examination of children with pheochromocytoma using the iodine 131 metaiodobenzylguanidine scan provides an accurate diagnosis of adrenal and extra-adrenal tumors, thus making feasible resection of this rare tumor with complete cure.

3-Iodobenzylguanidine

Sub-clinical Cushing's syndrome in patients with adrenal gland incidentalomas. Pitfalls in diagnosis and management.

Widespread use of contemporary imaging techniques (ultrasound, computerized axial tomography, and magnetic resonance imaging scans) have led to the incidental discovery of asymptomatic adrenal neoplasms with increasing frequency. Patients with such adrenal "incidentalomas" typically have no clinical manifestations of adrenal cortical hyperfunction at the time of discovery. We have studied 122 patients with asymptomatic adrenal masses ranging in size from 2 to 7 cm in diameter from 1978 to 1988. Selected patients, after adrenal metastases, pheochromocytoma, myelolipomas, and cysts were ruled out, were further evaluated for adrenal cortical hyperfunction by measuring urinary 17-hydroxysteroids, 17-ketosteroids, and free cortisol, serum A.M., P.M. cortisol, and plasma ACTH levels. These values were also measured before and after dexamethasone suppression. NP-59 adrenal scintiscans were performed on all patients. Six patients were identified with sub-clinical Cushing's syndrome. Baseline cortisol levels were normal in each of these patients. Loss of diurnal rhythm appeared to be the most sensitive indicator of abnormal adrenal cortical function. When adrenalectomy is performed in such patients, especially when contralateral adrenal gland suppression is evidenced by NP-59 scanning or other biochemical assessment, perioperative steroids should be administered in a manner similar to that used for patients with symptomatic Cushing's syndrome. Unilateral adrenalectomy in a patient with an asymptomatic adrenal adenoma, insufficiently studied, may result in Addisonian crisis.

Adenoma

Hürthle cell neoplasms of the thyroid.

The approach to Hürthle cell neoplasms of the thyroid gland remains controversial because there is no consensus on the criteria used to establish malignancy. Invasion into the thyroid capsule, blood vessels, and contiguous structures in the neck and lymph nodes, or distant metastases establishes malignancy. Benign Hürthle cell lesions should be treated with total lobectomy and isthmusectomy. Total thyroidectomy is the recommended treatment for malignant Hürthle cell lesions.

Age Factors

The role of adrenalectomy in Cushing's syndrome.

Forty-four patients with Cushing's syndrome were treated by adrenalectomy between 1975 and 1989. Twenty patients had adrenal adenomas: 13 with obvious Cushing's syndrome and 7 whose disease was subclinical, detected after evaluation of an incidentally discovered adrenal mass (es). Twelve patients underwent bilateral adrenalectomies for Cushing's disease after failed transsphenoidal explorations and pituitary irradiation. Six patients had primary adrenal hyperplasia, five as manifestations of Carney's complex. Two others underwent bilateral adrenalectomies for ectopic adrenocorticotropic hormone from carcinoid tumors. Four patients had adrenocortical carcinoma treated with transabdominal adrenalectomy. Three are alive from 8 years to 5 months. There was one postoperative death (2.3%) caused by coagulopathy and multiple organ failure and three (7%) minor postoperative complications. Follow-up showed good to excellent results in 95% of patients. It is concluded that adrenalectomy provides prompt relief from the severe morbidity of Cushing's syndrome regardless of the cause. It is the treatment of choice for adrenal adenomas, carcinomas, primary hyperplasia, and selected patients with Cushing's disease.

Adenoma