Embryonal rhabdomyosarcoma of the epididymis presenting as epididymitis: A case report

Abstract

Paratesticular rhabdomyosarcoma (RMS) is an extremely rare malignancy in adults, accounting for 7% of all RMS cases and 6% of all non-germinal intrascrotal tumors. The clinical signs are similar to those of a hydrocele or testicular tumor, typically presenting as a unilateral, painless mass in the inguinal canal or scrotum. No specific serum markers are currently available for this tumor. RMS of the epididymis is extremely rare. Particularly when it is associated with epididymitis, this malignancy is usually overlooked. We herein present a case of epididymal embryonal RMS, manifesting an painful scrotal edema, misdiagnosed as epididymitis. The patient received 3 cycles of adjuvant chemotherapy postoperatively and remained disease-free after 4 years of follow-up.

Keywords: embryonal rhabdomyosarcoma; epididymis; epididymitis.

Figure 1.

Hematoxylin and eosin staining of rhabdomyosarcoma. (A) Left, highly cellular anaplastic tumor; and midline, poorly cellular myxomatous tissue with ill-defined, infiltrative growth (magnification, ×100). (B) Spindle cell variant, cytoplasmic eosinophils with atypical nuclei and rhabdomyoblast with eccentrically placed nuclei with prominent nucleoli (magnification, ×400).

Figure 2.

Immunostaining of rhabdomyosarcoma. (A) Tumor cells exhibiting cytoplasmic positivity for actin (magnification, ×200); (B) nuclear positivity for myogenin (magnification, ×200).