Surgical Management of a Glioma-Associated Oncogene 1–Altered Mesenchymal Neoplasm Surrounding the Calcaneus

CASE: A 23-year-old male with no medical history presented with a painless, slowly enlarging heel mass present for 5 years. Physical examination revealed a firm lesion with mild varicosities. Magnetic resonance imaging demonstrated a 4.3 × 1.7 × 4.2-cm lobular mass with peripheral enhancement. Advanced molecular workup confirmed a glioma-associated oncogene 1 (GLI1)-altered mesenchymal neoplasm-a rare, emerging tumor with evolving classification and diagnostic challenges. The mass was widely excised with negative margins, followed by free-flap reconstruction. CONCLUSION: GLI1-altered neoplasms are rare, unpredictable tumors requiring meticulous resection and multidisciplinary surveillance. This novel presentation from the subcutaneous soft tissue surrounding the calcaneus supports adequate excision and surveillance involving patient-specific considerations.