Chondroblastoma with associated aneurysmal bone cyst of the cuboid.

The authors describe a young adult patient with a chondroblastoma and associated aneurysmal bone cyst of the cuboid. Although chondroblastoma has been reported to occur in tarsal bones, the cuboid is a very rare location. The association of chondroblastoma with an aneurysmal bone cyst in long bones has been well documented. However, this association in the cuboid has not been reported in the English literature. A 20-year-old man with a 4-month history of foot pain localized to the lateral border of the foot and ankle presented with an expansile lesion in the cuboid bone with a nondisplaced pathologic fracture. A computed tomography scan showed an expansile lesion with discontinuity of the cortex, and magnetic resonance imaging showed marrow replacement within the cuboid with surrounding periosteal edema. An open biopsy was performed, followed by curettage and cementation of the lesion. The histology showed a chondroblastoma with an associated aneurysmal bone cyst of the cuboid.