Abstract
This study was designed to consider the cytomorphological spectrum, differential diagnosis, and the role of ancillary studies in small-cell tumors of the liver. Three independent pathologists reviewed cytological slides from 91 cases of small-cell tumors of the liver. The results were compared with the findings of three recently published studies (Cytopathology 11 (2000) 262-267; Diagn Cytopathol 19 (1998) 29-32; and Acta Cytol 40 (1996) 937-947). The role of immunohistochemistry in reaching timely and specific diagnoses was also examined. The diagnostic categories included 44 cases of metastatic small-cell undifferentiated carcinoma, 15 cases of metastatic neuroendocrine carcinoma, 10 cases of metastatic adenocarcinoma, 7 cases of malignant lymphoma, 4 cases of hepatocellular carcinoma with small-cell features, 2 cases of cholangiocarcinoma, 1 case of poorly differentiated carcinoma, and 8 cases of rare tumors including granulosa cell tumor (2 cases), sarcoma (4 cases), malignant melanoma with small-cell features (1 case), and meningioma with small-cell features (1 case). Metastatic granulosa cell-tumor, metastatic melanoma, and metastatic meningioma should be included in the differential diagnoses of small-cell malignancies found in the liver.