Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To extend flow cytometry (FC) to the diagnosis of nonhematopoietic neoplasms, we have developed new flow cytometric assays to identify expression of cytokeratin, epithelial cell adhesion molecule (EpCAM)/epithelial glycoprotein-2, myogenin, and CD99. To validate these assays, we correlated the flow cytometric results with the histologic and immunohistochemical results on paraffin-embedded tissue in a series of 21 cases, including 17 carcinomas, 1 atypical carcinoid, 2 rhabdomyosarcomas, and 1 Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET). Six of 7 assayed carcinomas and the carcinoid were positive for cytoplasmic cytokeratin by the flow cytometric assay. EpCAM was expressed by 11 of 12 carcinomas that were assayed by FC. Both rhabdomyosarcomas expressed myogenin by FC, and the ES/PNET case expressed CD99. Interestingly, the blast-associated antigen CD90 was expressed uniformly on the ES/PNET case and on subsets of cells in the rhabdomyosarcoma and carcinoma cases. Potential applications of the flow cytometric assay to nonhematopoietic neoplasms will include evaluating samples with limited material, monitoring disease persistence and recurrence in patients with previous diagnoses, and making rapid diagnoses in urgent cases.
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PMID:Lineage-specific identification of nonhematopoietic neoplasms by flow cytometry. 1276 Feb 82

High-level microsatellite instability (MSI-high) is found in approximately 15% of all colorectal adenocarcinomas (CRCs) and in at least 20% of right-sided cancers. It is most commonly due to somatic hypermethylation of the MLH1 gene promoter region, with familial cases (Lynch syndrome) representing only 2% to 3% of CRCs overall. In contrast to CRC, MSI-high in appendiceal adenocarcinomas is rare. Only 4 MSI-high appendiceal carcinomas and 1 MSI-high appendiceal serrated adenoma have been previously reported, and the prevalence of MSI in the appendix is unknown. We identified 108 appendiceal carcinomas from MD Anderson Cancer Center in which MSI status had been assessed by immunohistochemistry for the DNA mismatch-repair proteins MLH1, MSH2, MSH6, and PMS2 (n=83), polymerase chain reaction (n=7), or both (n=18). Three cases (2.8%) were MSI-high, and 1 was MSI-low. The 3 MSI-high cases included: (1) a poorly differentiated nonmucinous adenocarcinoma with loss of MLH1/PMS2 expression, lack of MLH1 promoter methylation, and lack of BRAF gene mutation, but no detected germline mutation in MLH1 from a 39-year-old man; (2) an undifferentiated carcinoma with loss of MSH2/MSH6, but no detected germline mutation in MSH2 or TACSTD1, from a 59-year-old woman; and (3) a moderately differentiated mucinous adenocarcinoma arising in a villous adenoma with loss of MSH2/MSH6 expression, in a 38-year-old man with a strong family history of CRC who declined germline testing. When the overall group of appendiceal carcinomas was classified according to histologic features and precursor lesions, the frequencies of MSI-high were: 3 of 108 (2.8%) invasive carcinomas, 3 of 96 (3.1%) invasive carcinomas that did not arise from a background of goblet cell carcinoid tumors, and 0 of 12 (0%) signet ring and mucinous carcinomas arising in goblet cell carcinoid tumors. These findings, in conjunction with the previously reported MSI-high appendiceal carcinomas, highlight the low prevalence of MSI in the appendix as compared with the right colon and suggest that MLH1 promoter methylation is not a mechanism for MSI in this location.
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PMID:High-level microsatellite instability in appendiceal carcinomas. 2364 60