Xanthogranulomatous epithelial tumour of the calcaneus in a 32-year-old female: a rare entity.
Darshana Sanghvi, Amrit Kaur Kaler, Manit Gundavda et al.
✦ AI-curated · Sources linked
Case in brief
A 32-year-old woman presented with 10 months of heel pain. Imaging showed a lytic lesion in the calcaneus, with giant cell tumour of bone and solid aneurysmal bone cyst among the initial considerations. Histology showed a bland lesion containing xanthomatous histiocytes and giant cells; diffuse cytokeratin positivity on immunohistochemistry prompted further characterization. Molecular testing confirmed an HMGA2::NCOR2 fusion and found no H3F3A or USP6 alterations, establishing primary intraosseous xanthogranulomatous epithelial tumour.
What made this case unusual
The calcaneal lesion mimicked more familiar giant cell-rich bone tumours radiologically and histologically, while diffuse cytokeratin staining and molecular confirmation identified XGET.
Diagnostic / clinical pearl
For a giant cell-rich lytic bone lesion with diffuse cytokeratin positivity, molecular testing for HMGA2::NCOR2 can help distinguish XGET from GCTB and solid aneurysmal bone cyst.