Cytomorphological Findings of Follicular Dendritic Cell Sarcoma on Fine-Needle Aspiration Cytology

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm arising from follicular dendritic cells of germinal centers. The most common site of origin is lymph nodes and it may mimic a variety of tumors at that location, including carcinomas and sarcomas. Diagnosis is frequently missed on cytology as there are very few case reports describing the cytological characteristics of the lesion. Even on histology, a high degree of suspicion is required for an appropriate diagnosis.

A 60-year-old male presented with a gradually increasing left submandibular mass that had been present for 3 months. Fine-needle aspiration cytology (FNAC) was performed, showing many clusters as well as scattered epithelioid cells with spindled to oval nuclei, nuclear pleomorphism, grooves, inclusions, and uniformly dispersed mature lymphocytes throughout the smears. The diagnosis of FDCS was suspected and was confirmed on histopathology and immunohistochemistry.

FNAC can be a cheap, easy, and helpful tool in obtaining a diagnosis of FDCS as there are few characteristic cytological features that are better recognized than histology.