Nevus lipomatosus cutaneous superficialis on the shoulder: A case report with MRI findings.

Nevus lipomatosus cutaneous superficialis is a rare disease, and its magnetic resonance imaging features have not been reported. A 1-year-old male infant was admitted to our hospital for examination of a mass on his right shoulder. Magnetic resonance imaging revealed hypertrophic skin and a lipomatous subcutaneous mass, consistent with a hamartoma-like lesion or mesenchymal tumor; after surgery, the tumor was pathologically diagnosed as nevus lipomatosus cutaneous superficialis. To the best of our knowledge, this is the first case report focusing on the magnetic resonance imaging features of this disease. Hypertrophy of all skin structures involved (epidermis, dermis, and subcutaneous fat) may be specific to nevus lipomatosus cutaneous superficialis, enabling its differentiation from other tumors.