Cytopathology of a primary follicular dendritic cell sarcoma of the liver of the inflammatory pseudotumor-like type.

Follicular dendritic cell (FDC) sarcoma is an exceedingly uncommon tumor of lymph nodes and extranodal tissues. The inflammatory pseudotumor (IPT)-like variant of FDC sarcoma of intraabdominal location is considered a separate entity, with different clinical and pathological features than those of the classic FDC tumor. There have been only 12 cytological reports of FDC sarcomas in the literature. Two of them were metastases to the liver and, like our case, had features of IPT. Fine-needle aspiration biopsy (FNAB) and imprint and scrape cytology from the surgically excised tumor here reported revealed spindle tumor cells with moderate pleomorphism, nuclear grooves, prominent nucleoli, and cytoplasmic processes, admixed with inflammatory cells. To the best of our knowledge, this is the first cytology report of a primary hepatic FDC tumor. The cytological findings permit the recognition of this tumor. However, confirmation by inmunohistochemistry (IHQ) is mandatory for a definitive diagnosis.