Calcaneal Giant Cell Tumor Masquerading as Lateral Ankle Sprain - A Rare Case Report and Review of Literature.

Introduction: Giant cell tumor (GCT) of bone is one of the most commonly encountered bone tumors in any orthopedic surgeon's routine practice. Although in most instances the age, sex, location, and clinical presentation are typical there is always a chance of encountering an atypical case with an anomalous presentation. Case Report: Benign bone tumors such as GCT are often diagnosed with a symptomatology typical of bone tumors, however, there have been many reported cases wherein they were diagnosed incidentally as part of investigation into a different disease manifestation. These nuances are of more significance in case of GCT as it is a benign aggressive tumor and the prognosis after treatment is highly dependent on earlier diagnosis allowing for increased chances at limb salvage and functional restoration as compared to more radical treatment options.Lateral ankle sprain is a commonly encountered disease entity and, as such, enjoys a very benign progression with conservative management.Our patient was initially diagnosed on outpatient basis as a case of ankle sprain based on the history and clinical features, However, worsening of symptoms on conservative management prompted us toward the presence of a more sinister pathology. Subsequent radiological and histopathological investigations helped in the definitive diagnosis of GCT of calcaneus. Conclusion: We present to you a case of calcaneal GCT masquerading as lateral ankle sprain which is a rare presentation and such cases need to be evaluated meticulously with respect to their diagnostic algorithm and treatment challenges.