Cutaneous Malignant Melanoma With Rhabdoid Morphology and Smooth Muscle Differentiation: A Challenging Histopathologic Diagnosis

Am J Dermatopathol. 2017 May;39(5):397-403. doi: 10.1097/DAD.0000000000000792.

Abstract

Divergent differentiation or metaplastic change is a rare feature exhibited occasionally in malignant melanoma (MM), which is characterized by the development of morphologically, immunochemically, and/or ultrastructurally nonmelanocytic cells within the tumor. Smooth muscle differentiation in MM is an exceedingly rare phenomenon reported only in a few cases in the literature. We report the case of a 69-year-old woman who presented with a pure dermal amelanotic MM with smooth muscle cell differentiation and an area of rhabdoid morphology, which made the accurate histopathologic diagnostic of MM challenging.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Aged
  • Biopsy, Needle
  • Cell Differentiation / physiology
  • Female
  • Follow-Up Studies
  • Humans
  • Immunohistochemistry
  • Melanoma / diagnostic imaging
  • Melanoma / pathology*
  • Melanoma / surgery*
  • Melanoma, Cutaneous Malignant
  • Myocytes, Smooth Muscle / pathology*
  • Positron-Emission Tomography / methods
  • Rare Diseases
  • Rhabdoid Tumor / pathology
  • Risk Assessment
  • Sentinel Lymph Node Biopsy
  • Skin Neoplasms / diagnostic imaging
  • Skin Neoplasms / pathology*
  • Skin Neoplasms / surgery*
  • Time Factors
  • Treatment Outcome