Matsuno Y, Mukai K, Noguchi M, Sato Y, Shimosato Y
Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
Acta Pathol Jpn. 1989 Jul;39(7):433-8. doi: 10.1111/j.1440-1827.1989.tb02458.x.
Eighteen cases of primary thymic carcinoma were reviewed from the viewpoint of glandular differentiation. Squamous differentiation was evident in 14 cases (83%). Immunohistochemical study revealed secretory component (SC)-positive carcinoma cells in 12 cases (67%), most of which were also associated with squamous differentiation. Three of these 12 cases contained areas with a definite glandular or microcystic structure with occasional epithelial mucin, and were diagnosed as adenosquamous carcinoma. Review of patients' medical records revealed that thymic carcinomas with a glandular element were more often resectable at surgery, and had a much better prognosis than those without a glandular element. However, further study on larger number of cases is necessary to confirm this relationship. Because SC-positive epithelial cells do exist in the non-neoplastic thymus, the presence of a glandular component suggests another direction of morphological and/or functional differentiation of thymic carcinoma cells in addition to the well-known squamous differentiation.
