Introduction: Extraskeletal soft tissue chondroma (ESSC) is a rare benign cartilaginous soft tissue tumour. It represents around 1.5% of all benign soft tissue tumours. ESSC is slow growing tumour arising from extra-osseous and extra-synovial location. Predominantly occurs in hands and feet especially in the fingers. We report a rare case of ESSC of right thumb treated with marginal excision.
Discussion: A 31 years-old gentleman presented with progressively increasing painless swelling over his right thumb past 7 months. The swelling is 3x3cm in size, volar aspect of right thumb interphalangeal joint. Swelling was lobulated, firm in consistency, mobile and non-tender. No neurological involvement. Plain radiograph of the right thumb demonstrated well demarcated soft tissue swelling palmar side of right thumb with internal calcification and no underlying bony erosion. Marginal excision was performed.
Intra operatively found that tumour is arising from flexor tendon sheath. Macroscopically tumour is greyish, firm, lobulated measuring 2.5x2x1.5cm. Histopathological examination revealed cartilaginous matrix with occasional binucleation of chondrocytes. There is presence of myxoid change areas,
calcification and ossification.
Conclusion: Clinical diagnosis might be challenging given the rarity of the disease. Combination of
clinical, radiological and histopathology examination are necessary to diagnose ESSC. Marginal en-bloc
excision is the first line of treatment to prevent local recurrenc
