Giant Solitary Osteochondroma of the Inferior Medial Calcaneal Tubercle: A Case Report and Review of the Literature

Small osteophytes are frequently encountered in the foot and ankle, and are not to be confused with true osteochondromas, which are relatively uncommon in this region. They most often affect long bones of the appendicular skeleton but may involve flat bones as well. Osteochondromas are benign osseous neoplasms with a distinct hyaline cartilage cap originating from the physis and cease growing with skeletal maturity. Osteochondroma are often treated conservatively unless they become symptomatic, painful, demonstrate rapid or new growth, enlarge after skeletal maturity, and/or exhibit signs of malignant transformation. In this report, we present a case of a giant (8 cm × 4.2 cm × 2.1 cm) osteochondroma in an adult occurring on the inferior medial tubercle of the calcaneus that underwent excision, with 3.5 years of follow-up without recurrence. To our knowledge this is the largest osteochondroma affecting the inferior medial tubercle of the calcaneus. This case demonstrates that large osteochondromas may occur in the foot, and also confirms that benign osteochondroma growth may occur in adulthood. A detailed review of osteochondroma occurrence in the foot is presented along with a review of the diagnostic work-up to evaluate for malignant transformation. Level of Clinical Evidence: 4.