Fine needle aspiration biopsy of small/intermediate cell tumors in the liver.  Considerations in a southeast Asian population. 
To assess the diagnostic problems and accuracy involved in rendering an exact cytologic diagnosis, including reference to a primary site of origin, on fine needle aspiration biopsies (FNABs) of small/intermediate cell tumors of the liver.  Thirty-five hepatic FNABs of small/ intermediate tumors, neuroendocrine tumors (NETs) and poorly differentiated or undifferentiated cancers occurring in adults were analyzed.  Ancillary studies, including immunohistochemistry, were performed whenever necessary.  All other relevant histopathologic sections and medical records were reviewed.  There were 26 metastases, while 9 were considered primary lesions.  The aspirates were categorized into 11 NETs (pancreas 5, lung 1, liver 2, unknown primary 3); 9 undifferentiated nasopharyngeal carcinomas; 2 small cell undifferentiated carcinomas (lung 2); 4 undifferentiated carcinomas, not otherwise specified (lung 1, pancreas 1, liver 1, unknown 1); 1 lobular-ductal carcinoma (breast); 1 glioblastoma multiforme (brain); 1 ovarian carcinoma; 1 non-Hodgkin's lymphoma (liver); and 5 primary hepatocellular carcinomas.  There was histologic and/or immunohistochemical confirmation in 25 cases (71%).  Some of the limitations in categorization of such tumors obtained by FNAB can be overcome by immunohistochemistry.  Information gleaned from a precise cytologic diagnosis can sometimes only favor a particular primary site.