Uncommon dwelling for a common swelling – Myositis ossificans of the foot

The benign swellings in the foot and ankle are very rare in occurrence when compared to the other regions of the body and they may mimic malignant tumours, thereby being a diagnostic and therapeutic challenge. Myositis ossificans is one such lesion which commonly occurs around large joints, can occur very rarely in the foot and mimic a malignant lesion both clinically and on histopathological studies in the early stages of the disease. A 30-year-old male presented with bony swelling on the medial aspect of the heel which was insidious in onset with gradual progression. There was no antecedent history of trauma. A calcified mass on the medial aspect of the calcaneum was seen on radiographs. Computed tomography images showed mineralisation indenting on the medial aspect of the calcaneum. Magnetic resonance images reported calcified mass in the quadratus plantae muscle encasing the Tibialis posterior, Posterior tibial artery and nerve, Flexor hallucis longus and Flexor digitorum longus. Excision biopsy confirmed the diagnosis. Hence an unusual site of presentation of a commonly presented mass is reported here