Nodular Melanoma

**Semantic type:** Neoplastic Process

**Definition:** A melanoma that arises from the skin, conjunctiva, and mucosal sites. It is characterized by a vertical growth phase and lacks a significant radial growth phase. It may or may not arise from a pre-existing nevus. Morphologically, it is characterized by the presence of cohesive aggregates of neoplastic melanocytes in the dermis that often exhibit an epithelioid appearance. The overlying epidermis is often involved.

**Synonyms:** - Nodular melanoma