Reed nevus (also known as pigmented spindle cell nevus of Reed) is an acquired, benign, melanocytic lesion most frequently classified as a variant of a Spitz nevus. A Reed nevus typically presents as an asymptomatic, single, 2-8 mm, dark brown to black macule or papule on the lower extremities of young adults. The lesion may also be found in children and older adults, though the prevalence decreases with increasing age. In addition to the lower limbs, Reed nevi may also be found on the trunk, upper extremities, head, and neck. It has been documented to have a female predominance.

The natural history of a Reed nevus consists of an initial rapid growth phase, subsequent stabilization, and ultimately, involution. This transformation is accompanied by changes in clinical appearance and dermoscopic findings. The final involution may explain why the lesion is uncommon in older adults.

Because clinical, dermoscopic, and even histopathologic features of a Reed nevus may overlap with those observed in melanoma, accurate identification is important to avoid misdiagnosis and inappropriate treatment. Rare cases of malignant behavior for Spitz nevi and Reed nevi are generally thought to have actually been melanomas that were misdiagnosed.

A rare variant of a Reed nevus, termed hypopigmented Reed nevus, has all the typical characteristics of a Reed nevus but lacks the typical heavy melanin deposition.