Radiological findings
Lateromedial, dorsopalmar, dorsomedial-palmarolateral and dorsolateral-palmaromedial oblique views were obtained from the left metacarpal region (Fig 1b and c) . A large expansile multicavitary mass was present at the proximomedial aspect of the third metacarpal bone with an excessive heterogeneous periosteal reaction characterized by multiple trabeculae. The borders of the mass exhibited a combination of indistinct and well-defined margins. The mass extended from the dorsomedial to the palmaromedial region of the third metacarpal bone and affected the dorsal edge of the second metacarpal bone as well with cortical destruction and well-defined geographic lysis involving the palmaromedial mid-diaphysis of the metacarpus II and III. The cortex of the second metacarpal bone was almost breached, but its distal and proximal parts remained intact. Based on the pathognomonic radiological signs, the most likely diagnosis was an osteosarcoma, and therefor surgical excision under general anesthesia, followed by histopathological tissue examination was recommended.