Recombinant interferon alpha-2b in patients with metastatic apudomas: effect on tumours and tumour markers. (1/17)

Malignant carcinoid tumours, islet cell tumours and medullary carcinomas of the thyroid are tumours with similar clinical features. In patients with unresectable or metastatic tumours leukocyte interferon (IFN) and recombinant human (rh) IFN have demonstrated efficacy. Twenty-four evaluable patients with progressive tumours were treated with 2.5 megaunits rh IFN alpha-2b, administered once daily subcutaneously, for a median duration of 7 months (range 0.5-37+). Two carcinoid patients demonstrated a response in tumour size, 80% showed stable disease (SD). Sixty percent of the carcinoid patients with elevated urinary 5-hydroxyindoleacetic (5-HIAA) levels reached a biochemical partial response of the urinary 5-HIAA levels (median duration 13.5 months). In the patients with an islet cell or medullary tumour and an elevated tumour marker, the marker did not further increase. Of the 12 carcinoid patients evaluable for a symptomatic response, ten (83%) experienced a relieve of symptoms. IFN alpha-2b dose reduction or discontinuation due to toxicity was necessary in three and ten patients, respectively. No neutralising IFN alpha-2b antibodies developed despite prolonged treatment. In conclusion, IFN alpha-2b had a beneficial effect in patients with progressive tumours, while long-term IFN alpha-2b treatment did not augment neutralising antibodies. In view of the IFN alpha-2b-related toxicity, administration of IFN alpha-2b on alternating days may be preferable.  (+info)

Relative usefulness of electron microscopy and immunocytochemistry in tumour diagnosis: 10 years of retrospective analysis. (2/17)

AIMS: To determine retrospectively the relative usefulness of electron microscopy and immunocytochemistry for tumour diagnosis; to monitor the influence of new antibodies and antisera on the use of these techniques in one laboratory. METHODS: During 1980 to 1989 inclusive, 726 tumours were examined by electron microscopy, 862 by immunocytochemistry, and 286 by both techniques. The choice of techniques and, for immunocytochemistry, the range of antibodies used were compared between each category of final diagnosis. RESULTS: During the study period there was a sharp fall in the use of electron microscopy and a corresponding rise in immunocytochemistry. These trends applied to all categories of final tumour diagnosis, but the use of electron microscopy was sustained longer for lesions suspected or eventually confirmed to be melanomas or amine precursor uptake decarboxylation cell carcinoma (APUDomas)--for example, carcinoid tumours. The immunocytochemistry:electron microscopy use ratios ranged from 2.07:1 to 0.44:1 for the categories in which lymphoma and APUDoma, respectively, were the final diagnoses. The abandonment of electron microscopy for suspected or confirmed lymphomas and carcinomas corresponded to the increasing availability of relevant antisera and antibodies. CONCLUSIONS: The wider application of immunocytochemistry for tumour diagnosis is endorsed, but electron microscopy should be retained for selected cases in which the results of immunocytochemistry might be predictably ambiguous or otherwise unhelpful.  (+info)

Production of calcitonin, adrenocorticotropic hormone, and beta-melanocyte-stimulating hormone in tumors derived from amine precursor uptake and decarboxylation cells. (3/17)

The tumor production of human calcitonin (CT) was examined by radioimmunoassay, and it was found that 50 of 85 (59%) tumor tissues collected at random contained immunoreactive CT. These tumors were grouped as to whether they were derived from the amine precursor uptake and decarboxylation (APUD) series. The group that was derived from APUD cells showed appreciable amounts of CT in 30 of 31 (97%) of these tumors or in 20 of 21 (95%) when the medullary carcinomas of the thyroid were excluded. However, of the non-APUD group of tumors only 20 of 54 (37%) were found to contain CT, so that the difference between these two groups was highly significant (p less than 0.001). Of the tumors with ectopic adrenocorticotropic hormone-melanocyte-stimulating hormone production, 12 of 14 were shown to contain CT. These data indicate that CT is a common product of the APUD tumors and that tumor production of CT is often associated with that of adrenocorticotropic hormone and beta-melanocyte-stimulating hormone.  (+info)

Cyclical release of vasoactive intestinal polypeptide (VIP) from a pancreatic islet cell apudoma. (4/17)

A patient is described who presented with the classical symptomatology and profound electrolyte disturbance of the Verner-Morrison syndrome due to a pancreatic apudoma secreting vasoactive intestinal polypeptide (VIP). Diagnosis was confirmed by plasma VIP as measured by a radio-immunoassay technique now available. It is suggested that the cyclical nature of the symptoms in this case was due to cyclical release of VIP from the tumour in response to an unknown stimulus. Perfusion studies confirmed the excess secretory state of water, sodium and chloride in the small intestine. Symptoms were completely abolished by surgery and the progress is being monitored by means of serial plasma VIP estimations to detect any early recurrence of metastatic disease.  (+info)

Apudoma of the pancreas: benign or malignant? (5/17)

A middle-aged, obese, black woman complained of abdominal pain and tenderness in the left upper quadrant. An abdominal computerized tomographic (CT) scan revealed an encapsulated cystic mass in the tail region of the pancreas. Selective angiography confirmed mass and hypervascularity, definite encapsulation, and lack of capsular invasion. The diagnostic value of the CT scan, angiography, and special staining in classifying the excised pancreatic mass as an apudoma is discussed. Malignancy was excluded by the lack of capsular-vascular invasion and the absence of metastases. Nonfunctional status was determined by lack of hormone hypersecretion.  (+info)

ACTH-producing apudoma metastatic to the liver. (6/17)

A young man presented with combative psychosis and elevated levels of plasma adrenocorticotropic hormone (ACTH). A solitary vascular pancreatic mass and diffuse vascular hepatic nodules were demonstrated on selective splenic and hepatic arteriograms. These classic angiographic findings are used to emphasize the role of angiography in initial radiographic evaluation and to summarize the angiographic appearance of functioning pancreatic adenomas. Even though this is an aggressive tumor, early diagnosis and intensive treatment may allow prolonged remission, if not cure.  (+info)

Iodine-131 MIBG scintigraphy of neuroendocrine tumors other than pheochromocytoma and neuroblastoma. (7/17)

Metaiodobenzylguanidine (MIBG) locates most pheochromocytomas and neuroblastomas. The tracer is concentrated in intracellular storage vesicles by an active process. Many other neuroendocrine tumors of the amine precursor uptake and decarboxylation (APUD) series have hormonal storage vesicles and, thus, the potential to take up [131I]MIBG. A variety of neuroendocrine tumors in 57 patients were studied 1, 2, and 3 days after 0.5 mCi [131I]MIBG. Views from skull to pelvis were obtained. Results of MIBG scans were compared with all available imaging modalities (including plain radiography, liver scan, ultrasound, computed tomography, and angiography) and surgical exploration. The neuroendocrine nature of the tumor was determined by histology, immunohistochemistry, electron microscopy, and the assay of appropriate biogenic amines and peptide hormones. Results were (positive/total cases): carcinoids (four of ten), nonsecreting paragangliomas (three of three), sporadic medullary carcinomas of the thyroid (MCT) (one of five), familial MCT (one of 26), chemodectomas (two of five), oat cell carcinomas (zero of four), choriocarcinoma (one of one), atypical schwannoma (with storage granules) (one of one), Merkel cell skin cancer (one of one), islet cell carcinoma (zero of one). We conclude that a wide range of neuroendocrine tumors show [131I]MIBG uptake; tumors other than pheochromocytomas and neuroblastomas are less often seen scintigraphically, but in certain cases (e.g., carcinoid and nonsecreting paragangliomas) scintigraphy may be useful in depicting the extent and location of disease and may indicate therapeutic potential. Iodine-131 MIBG shows promise in the diagnosis and staging of tumors of varied types.  (+info)

Neuroendocrine (Merkel cell) carcinoma of the skin. Its natural history, diagnosis, and treatment. (8/17)

Over 400 cases of neuroendocrine (Merkel cell) carcinoma of the skin (NCS) have been reported. This tumor continues to pose problems in diagnosis and effective treatment for physicians unfamiliar with its biological characteristics. Reported here are five additional cases of NCS and the literature for this rare neoplasm is comprehensively reviewed. An early and accurate diagnosis is made possible by combining clinical presentation with results of histologic study, immunoperoxidase staining for neuron-specific enolase (NSE), epithelial membrane antigen (EMA), cytokeratins, and electron microscopy. NCS is an aggressive tumor. Depending on the length of follow-up, up to 40% of tumors locally recur, 55% develop regional nodal metastases, and 36% undergo distant metastasis. Survival is sex, but not age, dependent, with an overall 2-year survival rate of 72% (males 58% vs. females 79%). No standard procedure for initial and/or follow-up treatment for NCS exists. The authors recommend that NCS be treated, whenever possible, using the same rationale as applied for the treatment of squamous cell carcinoma of the skin.  (+info)

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