@entity808 is a rare markedly pigmented @entity1263 comprising cells with prominent melanization and schwannian features. The psammomatous variety is associated with @entity11930 , a @entity5 with spotty skin pigmentation. We present the first 2 reported cases of @entity808 arising in @entity1 with a history of @entity13687 , a rare @entity1709 believed to represent a failure of melanocyte migration to the epidermis during embryogenesis. Case 1 involves a 40-year-old @entity1 with a 1.8-cm, deeply pigmented, trigeminal nerve mass and @entity2118 and bone. Case 2 involves a 53-year-old @entity1 with a 1.5-cm mass adjacent to the clavicle. Microscopically, both masses consist of partially encapsulated epithelioid and spindle cells with abundant melanin pigment, arising in association with peripheral nerves. Morphological, immunohistochemical, and ultrastructural features support a diagnosis of @entity808 . No psammoma bodies are noted, and neither @entity1 exhibits any additional features of @entity11930 . @entity808 is most often benign but has been associated with malignant behavior in some cases. Distinguishing this @entity4847 from @entity320 can be difficult but is of great clinical importance due to differences in prognosis and treatment.

@entity808 arising in association with XXXX : 2 cases suggesting a shared mechanism.

@entity808 :: ('MESH:D009442', 'Disease') :: ['melanotic schwannoma', 'Melanotic schwannoma'] @entity1 :: ('9606', 'Species') :: ['woman', 'patients', 'patient'] @entity1263 :: ('MESH:D010524', 'Disease') :: ['peripheral nerve sheath tumor'] @entity11930 :: ('MESH:D056733', 'Disease') :: ['Carney complex'] @entity5 :: ('MESH:D009369', 'Disease') :: ['multiple neoplasia syndrome'] @entity13687 :: ('MESH:D009507', 'Disease') :: ['nevus of Ota'] @entity1709 :: ('MESH:D008548', 'Disease') :: ['dermal melanosis'] @entity2118 :: ('MESH:D010859', 'Disease') :: ['pigmentation of the maxillary sinus mucosa'] @entity4847 :: ('MESH:D018317', 'Disease') :: ['nerve sheath tumor'] @entity320 :: ('MESH:D008545', 'Disease') :: ['malignant melanoma']
@entity13687 :: (MESH:D009507,Disease) :: ['nevus of Ota']
