[A rare tumor of the median nerve in a young child: Intraneural perineurioma. About one clinical case].

Intraneural perineurioma is a rare benign peripheral sheath tumor, which is most prevalent in adolescents and young adults. It is characterized by focal perineural cell proliferation infiltrating the endoneurium leading to the macroscopic aspect of hypertrophic nerve. It typically presents a loss of motor function in the involved nerve. We report the case of a 3-year-old boy presented with painless, subcutaneous mass on the palmar aspect of his right hand without loss of motor function. Imaging studies showed a large mass within the median nerve suggesting schwannoma. Surgical exploration was undertaken. The tumor could not be removed without leading to motor and sensitive loss. Neurolysis of the hypertrophic fascicles was performed. Microbiopsies ruled out malignant tumor and could make the diagnosis of intraneural perineurioma of the median nerve. An annual clinical follow-up has been decided in order to detect any functional trouble such as loss of motor function.