Physiologic versus neoplastic C-cell hyperplasia of the thyroid: Separation of distinct histologic and biologic entities

摘要: BACKGROUND Although hyperplasia of C-cells has been described in association with various pathologic and physiologic conditions, criteria for its diagnosis are poorly defined. Both neoplastic C-cell proliferations have lumped together under the umbrella designation (CCH), creating considerable confusion among clinicians pathologists. METHODS In order to compare morphologic immunohistochemical characteristics two major types CCH, we examined thyroid sections 17 patients familial forms and/or neoplasia tissue 19 glands known reactive or CCH (at least 50 per one low power field, 100×). Hematoxylin eosin (H & E) stained stains calcitonin were assessed each case. RESULTS Physiologic was not recognized certainty on H E any cases due similarities between adjacent follicular cells. Detection this form hyperplasia, which predominantly diffuse, required immunostains quantitative analysis. Conversely, nodular diffuse easily identified conventional at periphery 11/12 (92%) medullary carcinomas (MTC). In other five cases, only finding thyroidectomy performed elevated serum levels detected via provocative biochemical screening identification mutated RET proto-oncogene by genetic The large, mildly moderately atypical, confined within basement membrane follicles. Moreover, these cells cytologically indistinguishable from those invasive MTC cells. CONCLUSIONS Physiologic biologically morphologically distinct entities. former cannot be requires immunohistochemistry analysis diagnosis. latter consists atypical that can sections. Consequently, number is no importance considered precursor (medullary carcinoma situ) carcinoma. Cancer 1996;77:750-6.