Sean Klepper M.D.
Stephen Lyle, M.D., ...
Also known as: Sclerosing Spitz nevus, desmoplastic nevus
- Most common on the extremities of adults
- Presents as a dome-shaped papule or nodule
- Ill-defined proliferation of large polygonal to spindled melanocytes within a fibrotic dermis, most often with no junctional component
- The melanocytes often show nesting in the more superficial aspects of the lesion and infiltrate as single cells between the thickened dermal collagen bundles in the deeper aspects (maturation).
- The melanocytes also tend to become smaller as they go deeper into the dermis.
- Occasional multinucleated giant cells and pleomorphic cells may be present, especially in the upper portions of the lesion.
- Mitoses are absent or very rare.