Psammomatous Melanotic Schwannoma
Psammomatous melanotic schwannoma (PMS) is a rare pigmented neural tumor that is frequently associated with Carney Syndrome. It affects adults and usually arises from spinal and autonomic nerves near midline. Uncommon locations include stomach, bone, soft tissues, heart, lung, liver and skin. Most common presenting symptoms are pain and neurologic symptoms in the affected part. Association of PMS with Carney syndrome has been reported in around 50% of cases. The tumor develops at an earlier age in those with Carney syndrome (avg. age 22.5 yrs) and about 20% of patients have multiple tumors. The image shows Schwann cell-like spindled and polygonal cells arranged in fascicles and syncytial sheets. The cells have hyperchromatic nuclei and show focally heavy melanin pigmentation. A few psammoma bodies are also present.