Chondrolipoma of the Ankle in a Child: A Case Report.

Chondrolipoma is an extremely rare variant of lipoma with cartilaginous metaplasia. The presence of nonlipomatous components can lead to a variety of entities in the differential diagnosis from the radiologic findings. We describe an unusual case of a chondrolipoma occurring in the right ankle of a 9-year-old female. Physical examination showed a 3.5-cm, elastic-hard, poorly mobile, nontender mass adherent to the Achilles tendon. Plain radiographs revealed a faintly calcified soft tissue mass without bone involvement. Magnetic resonance imaging showed a well-defined mass with 2 components with heterogeneous signal intensity, suggesting the coexistence of a fatty area and another nonlipomatous component. Marginal excision of the tumor was performed. Histologically, the tumor was composed of mature adipose tissue studded with islands of mature hyaline cartilage. Based on these findings, the tumor was diagnosed as a chondrolipoma. The patient had no evidence of local recurrence within 9 months of follow-up. To the best of our knowledge, this is the first case of chondrolipoma originating from the ankle in a child.