Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An intraepidermally developed epithelial cell tumor, forming multiple nests, was examined to identify its cytologic characteristics. Histochemically, the tumor cells contained neither glycogen nor lipid substance. By N-(7-dimethylamino-3-methyl-4-coumarinyl)maleimide staining, the cytoplasm of the tumor cells in the periphery of each nest was rich in SH groups but not in SS linkages, whereas centrally located homogeneous tumor cells contained SS diffusely but no SH. The tumor cells showed no activity of phosphorylase and a weak activity of succinic dehydrogenase. Immunohistochemically, antihair keratin monoclonal antibodies specific for hair cells decorated the tumor cells, but carcinoembryonic antigen staining showed no positivity. Ultrastructurally, the tumor cells underwent a keratinization forming a fingerprint pattern of keratin filaments; however, membrane-coating granules and marginal bands were not formed. These intraepidermal tumor cells may have cytologic natures similar to those of hair cortical cells. The term intraepidermal pilar epithelioma is proposed as a diagnosis for this tumor.
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PMID:Intraepidermal pilar epithelioma: a new dermatopathologic interpretation of a skin tumor. 245 Jan 9

Thyroid paragangliomas are rare tumors that arise from the inferior laryngeal paraganglia. Most patients are female and present with an asymptomatic thyroid nodule. Histologically, the tumor is composed of cells arranged in a well-defined nest (zellballen) pattern surrounded by a thin fibrovascular stroma. It is a diagnostic pitfall and is occasionally misdiagnosed as follicular neoplasm, medullary thyroid carcinoma, intrathyroid parathyroid proliferation, and especially secondary neuroendocrine tumors. Immunohistochemical stains (cytokeratin, parathyroid hormone, thyroid transcription factor 1, tyrosine hydroxylase, chromogranin A, synaptophysin, S100, calcitonin, carcinoembryonic antigen) are essential in establishing the diagnosis. Loss of succinate dehydrogenase complex, subunit B (SDHB), immunoexpression can be used to triage genetic testing because some mutations are associated with a higher risk for developing metastasis. Total thyroidectomy or lobectomy for solitary lesion is the preferred treatment. Elective lymph node dissection is usually not indicated. Postoperatively, patients should receive hormonal evaluation for functional disease and imaging for evaluation of multifocal or metastatic disease.
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PMID:Thyroid Paraganglioma. 2623 Jun 1