1/30. Overview of chronic diarrhea caused by functional neuroendocrine neoplasms.Eight different neoplastic disorders can cause chronic diarrhea attributable to humoral-mediated diarrhea. These include pancreatic endocrine tumor (PET) syndromes (gastrinomas, VIPomas, glucagonomas, somatostatinomas, PET's releasing calcitonin), carcinoid syndrome, medullary thyroid cancer, and systemic mastocytosis. Because these disorders are an uncommon cause of all chronic diarrheas (<1%), they are not often considered in the differential diagnosis, leading to a delay in diagnosis. This is problematic not only because all are treatable, but also because the neoplasm is frequently malignant. In this article, the characteristics and pathogenesis of the diarrhea, important clinical and diagnostic laboratory features, and treatment of each disorder are briefly reviewed, with an emphasis on recent insights.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
2/30. pheochromocytoma associated with neuroendocrine carcinoma. A new type of composite pheochromocytoma.The coexistence of pheochromocytoma and other tumor types in a single adrenal gland has been rarely documented. This type of pheochromocytoma is designated "composite" or "mixed," depending on whether the pheochromocytoma and the nonpheochromocytoma components show the same embryologic origin. The nonpheochromocytoma components reported in the composite pheochromocytoma include ganglioneuroma, ganglioneuroblastoma, neuroblastoma, and malignant schwannoma. The components found in the mixed pheochromocytoma include adrenal cortical neoplasms and spindle cell sarcoma. We report a unique case of composite pheochromocytoma in which the nonpheochromocytoma element is a neuroendocrine carcinoma. The histologic and the immunohistochemical profiles of the 2 distinct components of this tumor were typical for those of pheochromocytoma and neuroendocrine carcinoma. This dual differentiation was also supported by ultrastructural findings. This case not only broadens the morphologic spectrum of composite pheochromocytoma but also provides some additional insight into the histogenesis of this rare but fascinating type of tumor.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
3/30. Primary neuroendocrine carcinoma of the liver: difficult diagnosis of a rare neoplasm.Primary neuroendocrine neoplasms of the liver are extremely rare: about 30 cases only have been described in the literature. We report the case of a 42-year-old woman with a ten-year evolution. According to the previously reported cases, primary neuroendocrine carcinoma of the liver is usually multicentric, often mimicking liver metastases. The demonstration of the hepatic origin of a neuroendocrine carcinoma is often arduous. A careful surgical exploration and a prolonged follow-up are mandatory. The treatment of choice is surgical resection when possible. For progressive and unresectable disease, hepatic arterial chemoembolization may be considered. However, the prognosis of liver neuroendocrine tumours is much more favorable than that of hepatocellular carcinoma and progression has to be demonstrated before instauration of potentially harmful therapies.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
4/30. Imaging of nonlaryngeal neuroendocrine carcinoma.The imaging and pathologic features of three cases of nonlaryngeal neuroendocrine carcinoma of the head and neck are described. Neuroendocrine carcinomas represent malignant epithelial neuroendocrine neoplasms and are classified as three types: typical carcinoid (well differentiated), atypical carcinoid (moderately differentiated), and small cell neuroendocrine (poorly differentiated) carcinomas. The CT and MR imaging features of these tumors are nonspecific. Paranasal sinus neuroendocrine carcinomas showed expansion and destruction of the sinus, whereas metastatic neuroendocrine carcinomas to an intraparotid lymph node presented as a circumscribed parotid mass on CT scans.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
5/30. Hyalinizing spindle cell tumor with giant rosettes--a soft tissue tumor with mesenchymal and neuroendocrine features. An immunohistochemical, ultrastructural, and cytogenetic analysis.CONTEXT: Hyalinizing spindle cell tumor with giant rosettes is a recently described biphasic neoplasm of soft tissues that shares mesenchymal and neuroendocrine features. Its morphologic structure is distinctive, with the presence of hyalinized paucicellular foci that are termed rosettes. The cells around the latter display positive immunoreactivity for neuroendocrine markers. The small number of cases described to date indicates that they tend to be localized in the extremities. OBJECTIVE: To describe the clinicopathologic features of 2 unusual cases of hyalinizing spindle cell tumor with giant rosettes. methods AND RESULTS: One tumor was located in the prestyloid parapharyngeal space and the second in the left thigh. Both tumors were well circumscribed and surrounded by a thin capsule-like fibrous band without infiltrating projections. The rosettes were embedded in a spindle cell proliferation. Immunohistochemical stains showed positive results for S100 protein, synaptophysin, CD57, protein gene product 9.5, and neuron-specific enolase exclusively in the cells palisading the rosettes. These markers were negative in the spindle cell portions of the tumor. The latter were immunoreactive for factor xiiia, vimentin, HAM56, collagen IV, and CD68. vimentin was the only marker shared by the rosette-forming cells and the spindle cells. Ultrastructurally, the rosette-forming cells contained neurosecretory granules. This study describes the first cytogenetic analysis in this type of tumor revealing 2 cell lines, both containing a balanced translocation between chromosomes 7 and 16. Follow-up of the patients at 16 and 8 months did not disclose evidence of recurrence. CONCLUSIONS: These 2 new cases increase the awareness of hyalinizing spindle cell tumor with giant rosettes and demonstrate that it is a spindle cell neoplasm of unique cytogenetic rearrangements composed of dendritic, histiocytic, and fibroblastic cells admixed with cells that have neuroendocrine differentiation.- - - - - - - - - - ranking = 0.4keywords = neoplasm (Clic here for more details about this article) |
6/30. neuroendocrine tumors of the gastroenteric canal. Anatomopathological and diagnostic-therapeutic definition. Description of a case with a rare cecal localisation.The authors take the case of a neuroendocrine tumour of the cecum as the starting point for an analysis of the anatomopathological and diagnostic-therapeutic aspects of these neoplasms. Furthermore, the authors underline that neuroendocrine tumours (NET) of the colon represent an extremely rare nosological entity and that they are heterogeneous from a clinical and biochemical point of view, thus making a reliable preoperative diagnosis a problem that is still difficult to resolve today.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
7/30. Neuroendocrine pancreatic carcinoma causing sinistral portal hypertension.BACKGROUND: Non-functioning neuroendocrine pancreatic tumors are usually connected with non-specific syndromes. CASE REPORT: This case history presents the diagnosis and treatment of a non-functioning neuroendocrine pancreatic tumor causing sinistral portal hypertension and gastrointestinal bleeding in a 36-year-old man. RESULTS: A peripheral resection of the pancreas with splenectomy was performed. Intraoperative examination of the specimen revealed a malignant neoplasm, probably neuroendocrinal carcinoma. CONCLUSIONS: Peripheral resection of the pancreas with splenectomy treats not only the symptoms of segmental portal hypertension caused by pathology of this organ, but also allows the etiology of the disease to be determined.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
8/30. CT findings of non-functioning neuroendocrine pancreatic tumors.neuroendocrine tumors are rare neoplasms of the pancreas, representing 0.5% of all pancreatic tumors. Approximately, one-third of neuroendocrine tumors are hormonally inactive and called non-functioning neuroendocrine tumors. As these tumors remain clinically silent in their course of growth, they may attain great sizes without causing apparent clinical findings and commonly present in advanced stage. We report three cases of non-functioning neuroendocrine tumors with large sizes and discuss the radiological findings.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
9/30. The pigmented "black" neuroendocrine tumor of the pancreas: a question of origin.BACKGROUND: Pigmented neoplasms are extremely rare in the pancreas, and, when black pigment is identified, it often suggests the diagnosis of metastatic melanoma. The authors describe two patients with pigmented "black" neuroendocrine tumors of the pancreas. One patient had an incidental (0.5 cm) finding, and the second patient had a well-demarcated, 4.5-cm mass identified by computerized tomography that was consistent with an islet cell tumor. methods: The two neoplasms were resected surgically and studied by light microscopy using hematoxylin and eosin (H&E), Fontana-Masson, and iron stains. The neoplasms were examined immunohistochemically, and ultrastructural analysis was performed. RESULTS: H&E stains revealed nests of well-differentiated cells with small, round, centrally placed nuclei. The cytoplasm of the neoplastic cells was pink and granular and contained abundant brown-black pigment. Angiolymphatic and perineural invasion were identified in the larger neoplasm. Both neoplasms demonstrated a positive reaction with a Fontana-Masson stain, which was susceptible to bleaching, and a negative reaction to an iron stain. Immunohistochemical stains showed that neoplastic cells expressed chromogranin and synaptophysin but did not express HMB-45, S-100 protein, glucagon, or insulin. Ultrastructural examination revealed regular neurosecretory granules (100-150 nm) and large, irregularly shaped, electron-dense granules with small lipid inclusions consistent with lipofuscin. CONCLUSIONS: These pigmented pancreatic neoplasms are similar histologically and radiographically to the "black adenoma" of the adrenal gland. It is important to recognize these tumors, because they may mimic metastatic melanoma.- - - - - - - - - - ranking = 1.2keywords = neoplasm (Clic here for more details about this article) |
10/30. Cystic pancreatic neuroendocrine tumors: is preoperative diagnosis possible?Pancreatic neuroendocrine tumors rarely undergo cystic degeneration leading to a radiologic appearance, which is often interpreted as a pancreatic mucinous cystadenoma or pseudocyst. We reviewed our experience with 38 neuroendocrine tumors, four of which were cystic, and 24 other cystic pancreatic tumors (mucinous cystadenoma [n = 5], cystadenocarcinoma [n = 6], serous cystadenoma [n = 3], solid/cystic papillary neoplasm [n = 3], intraductal papillary mucinous tumor [n = 6], and mucinous adenocarcinoma [n = 1]) managed operatively between 1990 and 2000. This review was undertaken to identify clinical and pathologic features useful for preoperative diagnosis of cystic neuroendocrine tumors. Two of the four patients with cystic neuroendocrine tumors presented with abdominal pain, one patient was asymptomatic, and one patient had hypoglycemia. Three of the four cystic neuroendocrine tumors were identified by CT scan, and none were biopsied preoperatively. Preoperative diagnoses included mucinous cystadenoma in two patients (n = 2), pancreatic cystic neoplasm in one patient, (n = 1) and insulinoma in one patient (n = 1). All four cystic neuroendocrine tumors were benign and were completely resected (distal pancreatectomy [n = 2], enucleation [n = 2]). Cystic neuroendocrine tumors are difficult to diagnose preoperatively because the majority of these tumors are nonfunctional, and CT does not differentiate these tumors from other cystic neoplasms. Cystic neuroendocrine tumors represent a subgroup of pancreatic cystic and neuroendocrine tumors with malignant potential. Their high resectability rate further supports the role of surgical exploration and resection in the treatment of pancreatic cystic neoplasms.- - - - - - - - - - ranking = 0.8keywords = neoplasm (Clic here for more details about this article) |
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