Melanotic neuroectodermal tumor of infancy disseminated by a ventriculoperitoneal shunt and diagnosed from the inguinal sac.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare congenital neoplasm that originates from the neural crest cells, which give rise to the melanocytes of the skin and leptomeninges. We report a case of MNTI with neurocutaneous melanosis of a 28-month-old girl. She was born with hydrocephalus and several large congenital giant nevi. There were no findings except for hydrocephalus, after a ventriculoperitoneal (VP) shunt operation performed when she was 6 months old. She was operated on for a growing inguinal mass at 8 months. The specimen from the inguinal sac was positive for HMB45, vimentin, chromogranin, and neuron-specific enolase. Brain magnetic resonance imaging showed an extensive enhancing extra-axial mass with high signal intensity, along the cerebral spinal fluid space. We report a rare case of MNTI, diagnosed from an inguinal hernia sac, with a disseminated clinical manifestation.