Follicular dendritic cell sarcoma with atypical features surrounding undescended testis: description of a rare case.

Dendritic cell tumors are extremely rare neoplasms and occur both in nodal and extranodal sites. We report a case of an intra-abdominal follicular dendritic cell sarcoma (FDCS). The aim of this study is to describe histological, immunohistochemical, and ultrastructural features of FDCS in order to better define an abdominal mass with unusual immunophenotype and atypical clinical and radiological presentation.