8770/0 Pigmented spindle cell nevus of Reed


ICD-O-3 topography code: C44

Pigmented spindle cell nevus (Reed) is a benign nevus characterized by a proliferation of homogeneously darkly pigmented, spindled melanocytes arranged in vertical nests at the dermo-epidermal junction. The proliferation of melanocytes may be confined to the epidermis or extend into the papillary dermis. The overlying epidermis is often slightly hyperplastic and shows marked hyperpigmentation of the basal keratinocytes. In about 50% of cases, intraepidermal Kamino bodies are observed. An inflammatory infiltrate (lymphocytes, histiocytes, melanophages) is found within the papillary dermis. The lesion presents as a flat or slightly dome-shaped, symmetrical, sharply circumscribed papule or plaque. Microscopy typically reveals a ?starburst? pattern. Most commonly affected sites are the limbs, especially the thighs.
Pigmented spindle cell nevus (Reed) mainly affects children and young adults, with a peak in the 3rd decade of life, and shows a predilection for females. The lesion is benign and lacks metastatic potential. Local recurrence may occur after incomplete excision 1
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
3rd Edition
IARC Press: Lyon 2005