Fine-needle aspiration cytology of splenic hamartoma.

Bench-top fine-needle aspiration biopsy (FNAB) following splenectomy and nephrectomy from a 21-yr-old female of tuberous sclerosis with right renal angiomyolipoma and splenic hamartoma was performed for the correlation of the cytologic features with histologic findings and, along with the immunopathologic studies, for the establishment of a challenging preoperative diagnosis of splenic hamartoma. The postoperative bench-top aspirate of splenic hamartoma yielded small and large clusters of plump, spindly to polygonal cells in the blood-stained background with scattered small lymphocytes, comparable with the preoperative echo-guided FNAB. The histopathology and immunopatholgy of the splenic hamartoma from the bench-top aspirate cytoblock and splenectomy tissue were comparable, unveiling the red pulp tissue consisting of wider cord stromal tissue than its normal counterpart with sinus-like vascular channels lined by endothelial cells which were positive for CD8, CD34, factor VIII-related antigen, vimentin, as well as negative for muscle-specific actin, CD21, CD68, and cytokeratin, scattered dispersed CD3- and CD45RO-positive T-lymphocytes, and small clusters of CD20-positive B lymphocytes, with a dearth of fibrous trabeculae and organized white-pulp lymphoid tissue. A combination of cytologic features and immunopathologic results from the aspirate cytoblock along with the salient clinical information should enable an accurate preoperative diagnosis of splenic hamartoma.