Follicular dendritic cell sarcoma of the large intestine: A rare presentation

Follicular dendritic cell tumors are very rare neoplasms that often occur in lymph\udnodes. We report here a case in the colon, second in the series to be reported,\udin a 40 year male. The differentiation from gastrointestinal stromal tumor is\udemphasized. Tumor was involving the ascending colon without any obstructive\udfeature. Microscopically, tumor cells are arranged in a pattern-less pattern, focal\udshort fascicles. Tumor cells are large cells with varying shaped nuclei and ill defined\udcytoplasmic outline oval to irregular shaped nuclei with nuclear convolutions and\udsprinkling of lymphocytes intermingled with the tumor cells noted. The histological\udappearance resembled gastrointestinal stromal tumor. Immunohistochemically, the\udtumor is focally positive for CD23; while negative for C-kit, leucocyte common\udantigen (LCA), CD3, CD20, CD34, DOG-1, Smooth muscle actin (SMA), CD163,\uddesmin, S-100 protein and CD1a. So a final diagnosis of tumor of dendritic-histiocytic\udcell lineage favoring follicular dendritic cell tumor of malignant potential. So, it is\udinferred that follicular dendritic cell tumor entity should be considered in the list of\uddifferential diagnoses for gastrointestinal stromal tumo