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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatoblastoma exhibits a wide range of epithelial and mesenchymal lines of differentiation. Neuroendocrine differentiation in this tumor has not previously been reported. We investigated seven hepatoblastomas of different subtypes (five pure epithelial hepatoblastomas, including one small-cell hepatoblastoma, and two mixed hepatoblastomas) using a broad panel of antibodies against epithelial, mesenchymal, neural, and neuroendocrine markers, alpha-1-antitrypsin (alpha 1-AT), alpha-1-antichymotrypsin (alpha 1-ACT), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), serotonin, and 14 regulatory peptides. Chromogranin A-immunoreactive neuroendocrine tumor cells, some of which also exhibited immunoreactivity for serotonin and somatostatin, were found in the fetal and embryonal parts of the mixed hepatoblastomas. The osteoid-like material in the mixed hepatoblastomas contained cells with immunoreactivity for chromogranin A, neuron-specific enolase, keratin, and alpha 1-AT, alpha 1-ACT, AFP, and CEA, in addition to S-100 protein and vimentin. Parallels to the neuroendocrine differentiation in hepatoblastomas are found in tumors of the gastrointestinal tract and bronchopulmonary tree. These tumors may also exhibit a neuroendocrine component; that is, multidirectional differentiation may occur, as in hepatoblastoma. The immunoreactivity of some of the cells of the osteoid-like material for keratin, alpha 1-AT, alpha 1-ACT, AFP, CEA, and chromogranin A suggests that these cells--and probably the surrounding material--are of epithelial origin.
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PMID:Neuroendocrine differentiation in hepatoblastoma. An immunohistochemical investigation. 216 15

Analysis of the results of chemotherapy in patients with carcinoma of unknown primary site is complicated by the small sizes of most treatment series and patient heterogeneity. Careful evaluation of clinical and pathologic information may identify patients with a relatively high likelihood of response to systemic therapy. This includes patients in whom immunohistochemical studies or electron microscopy, or both, suggest a likely tumor type responsive to systemic therapy, such as prostate cancer, lymphoma, or a neuroendocrine tumor. Clinical evaluation can also identify potentially responsive patients, particularly those with clinical features in common with the extragonadal germ cell tumor syndrome. For patients who do not fit into these more treatable categories, most combination chemotherapy programs have response rates of less than 30% and median survivals of less than one year. Randomized trials have not established any clearly superior chemotherapy program. Regimens containing both Adriamycin (doxorubicin) and mitomycin-C produce response rates of approximately 25% but are associated with the possibility of severe hematologic toxicity, and rarely a syndrome resembling the hemolytic-uremic syndrome. The choice between chemotherapy and supportive care only must be individualized, and the latter option is appropriate for many patients. More detailed clinical and pathologic analyses in conjunction with clinical trials, particularly employing newer diagnostic techniques, are vital to provide better prospective data from which to identify relevant clinical subsets that allow an estimate of an individual patient's likelihood of response and the suitability of systemic chemotherapy.
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PMID:Empiric chemotherapy in patients with carcinoma of unknown primary site. 240 56

Cytologic specimens of neuroendocrine tumors metastatic to the liver were examined with regard to their silver staining properties after the application of argentaffin and argyrophil staining techniques (Masson, Grimelius and Sevier-Munger). In tumors with a content of serotonin (small intestine carcinoids), the presence of this substance was demonstrated cytologically as an argentaffin reaction in individual tumor cells; however, formalin fixation was a prerequisite for positive staining. Melanin in malignant melanoma cells displayed a positive argentaffin reaction, irrespective of the fixation used (air drying, formalin, Bouin's fluid or acetone-alcohol). Thus, serotonin and melanin can be distinguished in cytologic samples of neuroendocrine tumors by the use of the Masson argentaffin reaction with different fixatives. The nonargentaffin-positive neuroendocrine tumor cells were weakly stained or unreactive with the Grimelius argyrophil technique. The Sevier-Munger argyrophil technique was negative or gave a disturbing nonspecific background staining reaction that was difficult to interpret in the cytologic samples. Thus, the Grimelius method appears to be the most useful silver stain for identifying neuroendocrine tumor cells in cytologic material, irrespective of their hormone content, since both argentaffin-positive and argentaffin-negative cell samples were stained at least to some degree.
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PMID:Application of silver stains to cytologic specimens of neuroendocrine tumors metastatic to the liver. 241 33

Somatostatin is a peptide synthesized in many tissues that can act as a neurotransmitter, a systemic hormone, or a local hormone, and inhibits the secretion of hormones or other cell products. A long-acting synthetic analogue of somatostatin (SMS 201-995) has been developed which when administered subcutaneously has a biologic half-life of 90 to 120 minutes and can be administered 2 or 3 times per day. SMS 201-995 can lower plasma concentrations of growth hormone and somatomedin-C in patients with pituitary acromegaly, but no controlled trials to assess symptomatic response or change in tumor size have been done. In patients with pituitary thyrotropin-producing pituitary tumors, SMS 201-995 has been remarkably effective in producing biochemical and clinical responses and is the drug of first choice in this syndrome when tumor resection is not possible. In patients with the carcinoid syndrome, SMS 201-995 effectively reduces diarrhea, is the best available drug for treatment of carcinoid flush (effective in approximately 90% of cases), and is useful in treating carcinoid crisis. Eighty-five percent of patients with pancreatic islet cell tumors that produce vasoactive intestinal peptide will respond to SMS 201-995 with a reduction in diarrhea that often has been resistant to all other therapy. SMS 201-995 may also be useful in treating the symptoms in some patients with glucagonomas, growth hormone releasing hormone-producing tumors and insulinomas. Whether SMS 201-995 has a significant effect on gut neuroendocrine tumor growth remains uncertain. Certain nonmalignant diseases of the gut respond to somatostatin, including secretory diarrhea and fistulas of unknown cause. In general, SMS 201-995 has proved safe with few significant side effects, but whether the long-term use of the drug will result in an iatrogenic form of the somatostatinoma syndrome is uncertain.
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PMID:NIH conference. Somatostatin and somatostatin analogue (SMS 201-995) in treatment of hormone-secreting tumors of the pituitary and gastrointestinal tract and non-neoplastic diseases of the gut. 253 88

Anaplastic small cell carcinoma of the larynx is an uncommon neuroendocrine tumor. We report a case of this neoplasm of a 53-year-old male. The patient showed persistent hyponatremia accompanied with continuous loss of sodium in the urine, which resulted from inappropriate secretion of antidiuretic hormone (ADH). It is postulated that hyponatremia in this case was due to production of ADH by the tumor cells.
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PMID:Anaplastic small cell carcinoma of the larynx. 255 73

We report a case of a neuroendocrine tumor of the jejunum metastatic to the liver in a 26-year-old woman. Light and electron microscopy of this tumor revealed a poorly differentiated neoplasm composed of clusters of round to polygonal cells compatible with a diagnosis of neuroendocrine tumor. In the absence of identifiable silver-staining granules or immunocytochemical demonstration of a specific hormone product in tumor cells, this tumor cannot be further classified among the various neuroendocrine tumors that may arise in this location. However, interspersed among tumor cells was a distinct population of multinucleate giant cells having an appearance similar to benign osteoclasts. Enzyme histochemistry for 5'-nucleotidase, acid phosphatase, and nonspecific esterase each showed a dichotomous staining pattern for the small tumor cells and giant cells and suggest that the giant cells are not tumor derived, but represent a second, presumably reactive, cell population.
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PMID:Malignant neuroendocrine tumor of the jejunum with osteoclast-like giant cells. Enzyme histochemistry distinguishes tumor cells from giant cells. 257 48

We report on a 59-year-old female patient with a bladder tumor that was initially classified as anaplastic (undifferentiated) tumor. Posteriorly, electron microscopic and immunohistochemical analyses of the specimen revealed a neuroendocrine tumor distinct from a paraganglioma. The origin and prognosis of bladder carcinoids and small cell undifferentiated carcinomas are discussed. The authors indicate that the level of bladder wall infiltration is the most important prognostic parameter in these type of tumors.
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PMID:[Anaplastic tumor of the bladder with neurosecretory granules and benign courses]. 281 72

Twenty-nine patients with poorly differentiated neuroendocrine tumors of unknown primary site were seen at Vanderbilt Medical Center between May 1977 and February 1987. All patients had pathologic findings typical of neuroendocrine tumors by electron microscopy (22 patients), light microscopy (6 patients), or immunochemical staining (1 patient). Patient age ranged from 18 to 77 years; 21 were men and 8 were women; and 12 had no history of tobacco use. Seventeen patients had metastatic tumor at two or more locations. Common metastatic sites included the retroperitoneum, lymph nodes (particularly cervical), and mediastinum. In most patients, these neoplasms showed an aggressive biology, with rapid onset of symptoms and rapid growth of metastases. Major responses were seen in 18 of 25 patients who received combination chemotherapy; 6 patients achieved a complete response. Three patients remain disease-free more than 24 months after completing therapy. Four patients with single sites of disease received local therapy only; all remain disease-free 1 to 10 years after completion of therapy. In 4 patients, specific tumor types were eventually recognized: small cell lung cancer, 1; gastrointestinal carcinoid tumor, 2; and extragonadal germinal tumor with predominant neuroendocrine differentiation, 1. In the remaining 25 patients, no well-recognized type of neuroendocrine tumor was identified. Recognition of these tumors broadens the spectrum of neuroendocrine neoplasia, and also identifies a distinct subset of patients with poorly differentiated carcinoma of unknown primary site. Although optimal therapy remains undefined, these patients are usually responsive to combination chemotherapy, and long-term survival is attainable in a minority.
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PMID:Poorly differentiated neuroendocrine carcinoma of unknown primary site. A newly recognized clinicopathologic entity. 284 95

Five peptide hormones including calcitonin (CT) and gastrin-releasing peptide (GRP), serotonin (5HT), CEA, nervous tissue specific proteins and monoclonal antibody Leu-7 were immuno-histochemically studied on 60 cases of medullary thyroid carcinoma (MTC). In addition, localization of varied products in the tumor cells and its relations with the clinical features in some cases were evaluated. MTC contains a variety of products in many cases, and CT and CEA were positive in all cases. In 50 of the 57 cases (87.7%), GRP was positive, which suggested that GRP could be a novel tumor marker for this tumor. Furthermore, in tumor cells and C-cell hyperplastic foci, identical cells were sometimes revealed to possess both CT and GRP. Existence of somatostatin (SS), substance-P (SP), beta-MSH, 5 HT, Leu-7 and NSE in the tumor cells were confirmed. NSE was positive in 32 of the 47 cases (61.8%) which could confirm that MTC possesses neuroendocrine nature. In two cases of autopsy in which the tumors were highly malignant in clinical course and undifferentiated in histology, most tumor cells showed poor stainability for peptide hormones, suggesting that specific qualities as neuroendocrine tumor had been lost. In familial cases, the tumor tended to contain multiple substances.
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PMID:[Immuno-histochemical study of medullary thyroid carcinoma]. 289 90

The clinical and pathologic features of a vulvar neuroendocrine (Merkel cell) neoplasm are presented. Cytologic studies of material obtained from needle aspiration suggested that the tumor was a small cell neoplasm possibly of neuroendocrine derivation. The light-microscopic findings of sheets of small, uniform cells were consistent with a diagnosis of neuroendocrine tumor. The electron-microscopic characteristics, including the presence of neurosecretory granules, confirmed the diagnosis of a neuroendocrine (Merkel cell) carcinoma. Regional lymph node metastases were present at the time of initial surgery, and both local and distant metastases developed 8 months later. A comprehensive pretreatment metastatic evaluation is recommended. The role of chemotherapy for primary therapy is considered.
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PMID:Neuroendocrine (Merkel cell) carcinoma of the vulva: a case report and review of the literature. 299 60


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