Fig. 3
From: New and evolving concepts of melanocytic nevi and melanocytomas
Blue nevi. a Overview of the G alpha q signaling pathway. G-protein coupled receptors (such as CYSLTR1) activate Gq or G11 alpha subunits. The active GTP-bound alpha subunit activates phospholipase C beta which cleaves phosphatidylinositol 4,5-bisphosphate (PIP2), yielding the second messengers inositol trisphosphate (IP3) and diacylglycerol (DAG). DAG binds to and activates protein kinase C (PKC). b Blue nevus with sparsely distributed dendritic melanocytes in the dermis. c Dendritic melanocytes may have a periadnexal distribution. d Cellular blue nevus with more cellular areas in its lower portion. e Pale ovoid melanocytes arrayed in fascicles and nests are characteristic of cellular blue nevus
