A case of pediatric paratesticular rhabdomyosarcoma with epididymitis

Abstract

Paratesticular rhabdomyosarcoma is a rare malignancy arising from the mesenchymal tissues of the spermatic cord, epididymis, testis, and testicular tunica, and accounts for approximately 7% of all rhabdomyosarcomas. It often occurs in children but is known to have a better prognosis than disease at other urogenital sites. Patients typically present with painless unilateral scrotal swelling like a solid testicular tumor. However, we report an unusual case of delayed diagnosis of paratesticular rhabdomyosarcoma accompanied by epididymitis manifesting an painful scrotal swelling.

Keywords: Child; Epididymitis; Rhabdomyosarcoma.

Fig. 1

Magnetic resonance imaging for testis showed large epididymal mass (5 cm×4 cm×6 cm) on the right side was well-definedly demarcated and heterogenously enhanced. White arrow: epididiymal mass, white triangle: expelled testis.

Fig. 2

Macroscopic examination of testis showed that large epididymal mass was enlarged and well-demarcated yellow myxoid solid tumor (5.5×4.5 cm) with hemorrhagic change and focal necrosis. Normal testicular tissue was expelled peripherally. White arrows: epididiymal mass, white triangle: expelled testis.

Fig. 3

Microscopic examination with H&E and immunohistochemical staining. (A) The tumor is composed predominantly of primitive ovoid cells with scattered rabdomyoblasts. The rhabdomyoblast in this case have eccentric vesicular nuclei and abundant densely eosinophilic cytoplasm (H&E, ×200), (B) elongated rhabdomyoblasts with distinct cross-striations in eosinophilic cytoplasm (H&E, ×400), (C) diffuse, strong positive immunoreactivity for desmin (desmin stain, ×400), (D) diffuse, strong positive immunoreactivity for MyoD1 (MyoD1 stain, ×400).