Fibrosarcoma of anterior abdominal wall: A rare case report.

Introduction: Adult Fibrosarcoma (FS) is very rare and it constitutes approximately 1% of adult sarcomas. It is a malignant or intermediate (rarely metastasizing) tumor, composed of fibroblasts with variable collagen production. Fibrosarcomas usually involve the deep tissues of the extremities, trunk, head and neck. Adult FS usually appears in the fourth to sixth decades of life with a male predominance.

Case Report: A 62 years male patient presented with a large swelling over anterior abdominal wall since 20 years. Physical examination revealed a 15 × 15 cm large lobulated swelling situated over right hypochondrium and extending to epigastrium and right lumbar region. A wide local excision of tumour was done till the posterior rectus sheath. As the skin was involved the tumour was excised along with the skin. A large defect of around 20 × 20 cm was created in anterior abdominal wall. Mesh was placed over the defect and defect was closed by rhomboid flap reconstruction.

Discussion: The World Health Organization (2002) defined fibrosarcoma as a malignant tumor, composed of fibroblasts with variable collagen and, in classical cases, it has a herring bone pattern on light microscopy. Fibrosarcomas typically present as a non-specific soft tissue mass, sometime in a previously irradiated field or rarely in association with implanted foreign material. Fibrosarcomas metastasize to lungs and bone, especially the axial skeleton, and rarely to lymph nodes.

Conclusion: Although rare, fibrosarcoma should also be kept as a differential diagnosis in a case of anterior abdominal wall lumps.