Pigmented Spindle Cell Nevus (Reed Nevus)



Pigmented Spindle Cell Nevus (Reed Nevus)


David Cassarino, MD, PhD










Clinical photograph shows a pigmented spindle cell nevus on the knee of a young adult patient. This case shows dark pigmentation, except 1 area at the top of the lesion with depigmentation image. (Courtesy P. Hsu, MD.)






Histologic examination of a Reed nevus shows fusion of rete ridges by a proliferation of junctional pigmented spindle cells, which show a characteristic “streaming together” image pattern.


TERMINOLOGY


Abbreviations



  • Pigmented spindle cell nevus (PSCN)


Synonyms



  • Pigmented spindle cell nevus of Reed


Definitions



  • Melanocytic proliferation that is typically predominantly junctional and composed of a population of spindle-shaped cells with heavy cytoplasmic melanin pigmentation


  • Controversial, but often considered a variant of Spitz nevus, which occurs more frequently in adults


ETIOLOGY/PATHOGENESIS


Unknown



  • May be related to solar exposure in some cases


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Relatively uncommon tumors


  • Age



    • Typically young adults (usually < 35 years old)


  • Gender



    • More common in females


  • Ethnicity



    • Caucasian patients in most cases


Site



  • Most often presents on extremities, especially leg



    • Classic presentation is on thigh of a young woman


Presentation



  • Pigmented lesion



    • Usually papular, but can be nodular


Treatment



  • Surgical approaches



    • Complete excision is curative



      • Typically recommended in partially sampled lesions


      • To allow for complete evaluation to exclude more atypical areas


      • To prevent recurrence


Prognosis



  • Excellent; may recur if incompletely excised, but very low risk of developing melanoma


MACROSCOPIC FEATURES


Size



  • Usually small (< 1 cm)


MICROSCOPIC PATHOLOGY


Histologic Features

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Pigmented Spindle Cell Nevus (Reed Nevus)

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