A rare case of paratesticular pleomorphic rhabdomyosarcoma diagnosed by fine needle aspiration: a case report.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of children and young adults. It represents 6.5% of all malignant tumors in pediatrics with an annual incidence of 4 to 7 cases per million children. Embryonal RMS arising in paratesticular region in young males is a common entity, however pleomorphic RMS in such location is quite rare. An eighteen year old male presented with painless right scrotal mass measuring 7 x 6 x 5 cm of two year duration, which was reported on ultrasonography as extratesticular tumor. Fine needle aspiration showed cellular smears comprising of pleomorphic population of mostly singly scattered cells and few cell aggregates. Few isolated large cells with whip like cytoplasmic processes and faint cross-striations were also seen. A diagnosis of paratesticular malignant mesenchymal tumor probably RMS was made. Tumor was removed surgically with right sided orchidectomy. On histopathology, it was reported as pleomorphic RMS. There was focal lymphatic invasion and involvement of rete testis. Immunostaining of tumor cells revealed myogenin and desmin positivity. The case is being presented because of diagnosis of RMS on Fine needle aspiration and rare occurrence of pleomorphic RMS in paratesticular location.