Malignant triton tumor of the prostate: a case report

Malignant triton tumor (MTT) is a malignant peripheral nerve sheath tumor (MPNST) with rhabdomyoblastic differentiation. It is very rare and has an aggressive clinical course and poor prognosis. A 27-year-old male patient presented with complaints of difficulty in urination for 3 months. Computerized tomography (CT) imaging demonstrated a huge irregular mass localized in the prostate, with invasion into the bladder, seminal vesicle, cavernous bodies and rectum. In addition, generalized lymphadenopathy was shown at the pelvic and inguinal regions. After ultrasound-guided transrectal core biopsies of the prostate, the histopathological finding of rhabdomyoblasts among malignant Schwann cells in a tumor arising from a peripheral nerve supported by immunostaining (IHS) with vimentin, desmin, MyoD1 and S-100 confirmed the diagnosis. The patient underwent urinary diversion, palliative radiotherapy and interstitial chemotherapy and received traditional Chinese medicine. This patient appears to be the second reported case of the localization of an MTT in the prostate. Early diagnosis, the extent of surgical excision, and comprehensive treatment to improve the survival rate and the quality of life for patients with MTT are very important.