Intra articular synovial lipoma of the right tarsometatarsal joint- a rare case report

Intra articular synovial lipomas are very rare and only few cases have been reported till now. We are reporting a rare case of intra articular synovial lipoma of the tarsometatarsal joint in the right foot in a 38-year-old male who presented with dull aching pain in the plantar aspect of the foot while walking. The lesion was resected and subjected to histopathological examination, which showed well defined lobules of mature adipocytes separated by thin fibrous septa and covered by synovial lining. Immunohistochemistry with S100 antigen showed membrane positivity. A diagnosis of intra articular synovial lipoma of the tarsometatarsal joint of the right foot was made. Our English literature search failed to yield any information regarding the occurrence of synovial lipoma in small joints and our case may be the first of its kind.