Prostatic Rhabdomyoma in a Toddler: A Case Report With Molecular Characterization.

We present a 29-month-old male patient in follow-up due to pyelocaliceal dilation with a prostatic nodule incidentally found during ultrasound evaluation. Cysto video endoscopy was performed and a prostate biopsy, obtained. Microscopic evaluation showed a haphazardly distributed population of muscular cells with cross striations without evidence of mitosis or necrosis. Immunohistochemistry was positive for myogenin and desmin and negative for smooth muscle actin. Next generation sequencing was performed without finding any pathogenic variant or fusion in the tumor RNA. The patient received no further treatment, remained asymptomatic and continues in follow up, 3 years after initial diagnosis. We report a case of prostate rhabdomyoma in a toddler, an exceptional location that raises concern about differential diagnosis with its malignant counterpart, rhabdomyosarcoma, especially at this age.