Bednar tumor: report of a case with immunohistochemical and ultrastructural study

Ultrastruct Pathol. 2003 May-Jun;27(3):205-10. doi: 10.1080/01913120309935.

Abstract

A slowly growing tumor in the right shoulder of a 38-year-old white male, which felt like a superficial cystic mass, was studied. The spindle cells, which represented the main component of the tumor, were arranged in a typical storiform pattern and were positive for CD34 and focally for CD117. The pigmented cells were mostly found at the center of the storiform whorls and were negative for S-100 protein and HMB-45. Ultrastructurally, the tumor consisted predominantly of nondescript mesenchymal spindle cells that resembled fibroblasts. The tumor cells blended into a loosely arranged stromal tissue background. The general appearance of pigmented cells was very similar to the nonpigmented spindle cells. The pigment appeared to be a mature form of melanin granules. The lack of premelanosomes, cell injections, basal lamina, and pinocytotic vesicles was inconsistent with a neural origin/neural differentiation hypothesis for this tumor.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Antigens, CD34 / analysis
  • Biomarkers, Tumor / analysis
  • Dermatofibrosarcoma / chemistry
  • Dermatofibrosarcoma / surgery
  • Dermatofibrosarcoma / ultrastructure*
  • Humans
  • Immunohistochemistry
  • Male
  • Proto-Oncogene Proteins c-kit / analysis
  • Shoulder
  • Skin Neoplasms / chemistry
  • Skin Neoplasms / surgery
  • Skin Neoplasms / ultrastructure*
  • Treatment Outcome

Substances

  • Antigens, CD34
  • Biomarkers, Tumor
  • Proto-Oncogene Proteins c-kit