Invasive Inguinal Lymph Node Recurrence of a Perineal Rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is an aggressive soft tissue sarcoma derived from embryonic mesenchymal tissue. RMS can be found anywhere in the body, including the head and neck, extremities, pelvis, and genitourinary tract. Perineal-RMS is a rare and aggressive form of RMS. Patients often have a delayed presentation following onset of symptoms and frequently present with regional lymph node involvement and/or distant metastases. Primary tumor site is an important prognostic factor for RMS, with the perineal region being considered an unfavorable location. We present a case of Perineal RMS in a 6-year-old boy who later developed an invasive inguinal lymph node recurrence.