Vimentin-Positive Spider-Shaped Kupffer Cells:A New Clue to Cytologic Diagnosis of Primary and Metastatic Hepatocellular Carcinoma by Fine-Needle Aspiration Biopsy

Abstract

The identification of Kupffer cells highlighted by positive immunostaining for vimentin on direct smears was found to play an important role in the diagnosis of primary and metastatic hepatocellular carcinoma by fine-needle aspiration biopsy. The Kupffer cell, identified by vimentin staining, is spider-or star-shaped with multiple elongated and slender cytoplasmic processes. Direct smears obtained by fine-needle aspiration biopsy from 14 cases of hepatocellular carcinoma and 15 cases of metastatic carcinoma were stained with vimentin. The cytologic diagnoses were verified by histologic and/or clinical follow-up. All 14 cases of hepatocellular carcinoma, including 9 primary and 5 metastatic, contained significant number of vimentin-positive spider cells within tumorAlthough it is relatively uncommon in North America and Western Europe, hepatocellular carcinoma (HCC) is one of the most common primary hepatic malignancies worldwide with especially high incidence in China, Japan, and Africa.1 The liver is also the most frequent site of metastases from other primaries. Computed tomography (CT) or ultrasound guided fine-needle aspiration (FNA) biopsy has proved to be of great value in distinguishing primary from secondary hepatic neoplasms. However, one of the most common difficulties in hepatic FNA is to make a specific diagnosis of HCC. "7 To differentiate poorly differentiated HCC from metastatic adenocarcinoma is always a challenge for the cytopathologist. Various immunoperoxidase stains have been studied. Only polyclonal CEA showing a bile canalicular staining pattern has been found to be useful in the differential diagnosis of HCC, but the results are still not quite satisfactory regarding the poorly differentiated