Mesenchymal Chondrosarcoma Presenting as a Calcified Mass Extending Into the Inferior Vena Cava

Clin Nucl Med. 2026 Jun 1;51(6):544-546. doi: 10.1097/RLU.0000000000006435. Epub 2026 Mar 24.

Abstract

A 50-year-old man presented with lower abdominal pain. Imaging revealed a pelvic mass extending from the right internal iliac vein into the inferior vena cava. Fluorodeoxyglucose-positron emission tomography revealed intense uptake (SUVmax 13.97) without metastasis. Biopsy revealed a biphasic tumor with cartilaginous matrix and staghorn vasculature. Immunohistochemistry indicated positive for SMA, desmin, MyoD1, and NKX3.1. Moreover, genomic analysis identified a HEY1::NCOA2 fusion, confirming mesenchymal chondrosarcoma (MCS). Given the extent of the tumor, chemoradiotherapy was initiated. MCS is a rare, high-grade sarcoma with limited treatment options. Targeted therapies against HEY1::NCOA2-associated pathways are promising and are currently under investigation.

Keywords: HEY1::NCOA2; calcified mass; inferior vena cava; mesenchymal chondrosarcoma.

Publication types

  • Case Reports

MeSH terms

  • Calcinosis* / complications
  • Calcinosis* / diagnostic imaging
  • Calcinosis* / pathology
  • Chondrosarcoma, Mesenchymal* / complications
  • Chondrosarcoma, Mesenchymal* / diagnostic imaging
  • Chondrosarcoma, Mesenchymal* / pathology
  • Humans
  • Male
  • Middle Aged
  • Positron-Emission Tomography
  • Tomography, X-Ray Computed
  • Vena Cava, Inferior* / diagnostic imaging
  • Vena Cava, Inferior* / pathology