Rare case of pediatric calcaneal osteosarcoma masquerading as a cystic lesion

Abstract

BackgroundAlthough osteosarcoma remains the most common primary malignant neoplasm in the bone in the pediatric age group, involvement of the foot is extremely rare.Case presentationOur case demonstrates what appeared to be a bone cyst of the calcaneus at an outside institution after injury to the ankle. The patient was sent to our institution for further workup where a Computed Tomography scan revealed a permeative lytic lesion with faint calcifications. Based on our patient’s radiograph, an aneurysmal bone cyst might be included in the differential diagnosis. A telangiectatic osteosarcoma can also demonstrate a cystic and lytic appearance on radiographs. Interestingly biopsy confirmed our patient had an osteoblastic osteosarcoma.ConclusionsA high degree of suspicion is often necessary for diagnosis of calcaneal osteosarcoma, especially in the setting of injury, and should not be overlooked.