Malignant melanoma with a myxoid stroma: a diagnostic pitfall on fine-needle aspiration biopsy.

Published

Journal Article

Malignant melanoma (MM), both primary and metastatic, may be associated with a prominent myxoid stromal reaction causing diagnostic confusion on fine-needle aspiration biopsy (FNAB), most often with sarcomas that demonstrate a myxoid stroma, particularly malignant peripheral nerve sheath tumor (MPNST). We present a case of a 32-yr-old man with no past medical history who presented with a unilateral neck mass clinically suspicious for lymphoma. FNAB produced a specimen composed of large sheets of anaplastic cells encased in a myxoid stroma that was S100 and vimentin-positive but HMB-45-negative. A diagnosis of MPNST was made. Excision demonstrated a metastatic MM of unknown primary, with a prominent myxoid stromal reaction. A repeat HMB-45 was again negative. Electron microscopy demonstrated intracytoplasmic melanasomes and cisternae of rough endoplasmic reticulum with intracisternal parallel tubules, confirming the diagnosis. Although HMB-45 is typically negative in both tumors, S100 should be strongly positive in myxoid MM and only focal in MPNST.

Full Text

Duke Authors

Cited Authors

  • Elliott, D; Pitman, MB

Published Date

  • September 2001

Published In

Volume / Issue

  • 25 / 3

Start / End Page

  • 185 - 190

PubMed ID

  • 11536443

Pubmed Central ID

  • 11536443

International Standard Serial Number (ISSN)

  • 8755-1039

Language

  • eng

Conference Location

  • United States