Extraskeletal myxoid chondrosarcoma with neuroendocrine differentiation: a case report with fine-needle aspiration biopsy, histopathology, electron microscopy, and cytogenetics

Ultrastruct Pathol. 2003 Sep-Oct;27(5):363-8. doi: 10.1080/716100782.

Abstract

Although extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue sarcoma, its morphological, ultrastructural, and cytogenetical features have been well investigated. The authors describe a very rare variant of EMC with neuroendocrine differentiation. A 49-year-old woman presented with an 11-cm, deep-seated, lobulated soft tissue mass in the left thigh and a lymph node metastasis in the left groin. Analysis of fine-needle aspiration biopsy (FNAB) smears and a cellblock prepared from FNAB material, as well as histological sections of the excised tumor, showed a neoplasm composed of rounded and elongated cells arranged in strands and cords in a myxoid background matrix. The nuclei were rounded and often eccentric. The immunohistochemical phenotype was S-100 protein -, neuron specific enolase +, and chromogranin A+. Electron microscopy showed tumor cells harboring numerous mitochondria, partial basal lamina, and unequivocal neuroendocrine granules. Molecular genetic analysis revealed a TAF15/NR4A3 fusion, a characteristic rearrangement occurring in about 25% of cytogenetically investigated EMC. A few cases of EMC with neuroendocrine differentiation have been reported. However, the only previously described case with genetic information also displayed the t(9;17) instead of the more common t(9;22), suggesting an association between type of primary chromosome abnormality and neuroendocrine differentiation.

Publication types

  • Case Reports

MeSH terms

  • Biomarkers, Tumor / analysis
  • Biopsy, Needle
  • Cell Transformation, Neoplastic
  • Cells, Cultured
  • Chondrosarcoma / chemistry
  • Chondrosarcoma / genetics
  • Chondrosarcoma / secondary*
  • Chromogranin A
  • Chromogranins / analysis
  • Chromosomes, Human, Pair 17
  • Chromosomes, Human, Pair 9
  • Cytogenetic Analysis*
  • Cytoplasmic Granules / ultrastructure*
  • DNA, Neoplasm / analysis
  • Female
  • Gene Rearrangement
  • Humans
  • Immunohistochemistry
  • Middle Aged
  • Neurosecretory Systems / chemistry
  • Neurosecretory Systems / pathology*
  • Oncogene Proteins, Fusion / genetics
  • Phosphopyruvate Hydratase / analysis
  • Soft Tissue Neoplasms / chemistry
  • Soft Tissue Neoplasms / genetics
  • Soft Tissue Neoplasms / pathology*
  • Translocation, Genetic

Substances

  • Biomarkers, Tumor
  • Chromogranin A
  • Chromogranins
  • DNA, Neoplasm
  • Oncogene Proteins, Fusion
  • Phosphopyruvate Hydratase