Immunohistochemical analysis of the proliferative activity of neuroendocrine tumors from various organs. Are there indications for a neuroendocrine tumor-carcinoma sequence?
Small-cell neuroendocrine carcinomas (NECs) of the prostate are believed not to derive from benign orthotopic NE epithelial cells. Instead, an origin from a putative stem cell is actually the most favored concept. Whether this concept can also be applied to neuroendocrine tumors (NETs) of other organs, especially whether there are indications for well-differentiated NET-NEC sequence, is subject of the present study. A double-labeling technique for the proliferation marker MIB-1 and the NE markers chromogranin A (ChrA) and synaptophysin (SNP) was used for the immunohistochemical analysis of 45 well-differentiated NETs, 16 well-differentiated (low-grade) NECs, and 63 high-grade NECs of the esophagus, stomach, small intestine, appendix, colon, lung, prostate, and urinary bladder. The lowest proliferative activity was found in NETs (0.85% of tumor cells), and the highest activity was found in high-grade NECs (72.5%). The expression of ChrA was highest in NETs and lowest in high-grade NECs. None of the NETs and only sporadic cells in low-grade NECs showed double labeling (up to 0.05%). Up to 50% of the tumor cells in high-grade NECs were positive for MIB-1 and SNP. The percentage of double-labeled cells ranged between 0.9 and 39.6 (mean 9.7). No double-labeled cells were found in the normal epithelium adjacent to the tumors. Transitions from NET to NEC could not be observed. NETs and low-grade NECs differ in their proliferative activity from high-grade NECs, suggesting that they may arise from different precursor cell populations.
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Department of Pathology, Hegau Klinikum GmbH, Academic Teaching Hospital of the University of Freiburg, Singen, Germany. pathologie@hegau-klinikum.de
Köllermann
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D034961:Antigens, Nuclear; D001063:Appendiceal Neoplasms / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000032:analysis*; D002455:Cell Division; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis; D003110:Colonic Neoplasms / Q000737:chemistry; D004249:DNA Damage; D004938:Esophageal Neoplasms / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000737:chemistry; D019394:Ki-67 Antigen; D008175:Lung Neoplasms / Q000737:chemistry; D008207:Lymphatic Metastasis; D008297:Male; D018358:Neuroendocrine Tumors / Q000737:chemistry* / Q000473:pathology*; D009687:Nuclear Proteins / Q000032:analysis; D011471:Prostatic Neoplasms / Q000737:chemistry; D013234:Stem Cells / Q000473:pathology*; D013274:Stomach Neoplasms / Q000737:chemistry; D016708:Synaptophysin / Q000032:analysis; D001749:Urinary Bladder Neoplasms / Q000737:chemistry
D034961:Antigens, Nuclear; D014408:Biomarkers, Tumor; D053379:Chromogranin A; D002864:Chromogranins; D019394:Ki-67 Antigen; D009687:Nuclear Proteins; D016708:Synaptophysin