Introduction: Extraskeletal chondroma (EC) is a rare benign neoplasm predominantly composed of mature hyaline cartilage; it develops in the soft tissues without any connection to bone cortex, intra-articular synovium, or periosteum. To date, only few cases have been reported in the leg, mainly in the knee, thigh, and popliteal region.
Case report: We describe herein the case of a 42-year-old woman with a 4-year history of a slow-growing, painful swelling on the posteromedial region of her left leg. Magnetic resonance imaging showed the presence of a huge mass occupying soleus muscle, compressing, and displacing anteriorly gastrocnemius muscle. After an incisional diagnostic biopsy, a complete surgical excision of the tumor was performed. On the basis of clinicoradiological and morphological findings, a diagnosis of EC was made.
Conclusion: This report represents a clinicoradiological and morphological analysis about a very rare huge EC arising in the posteromedial region of the leg.
Keywords: Extraskeletal chondroma; differential diagnosis; leg; soft tissue.