[A giant thoracoabdominal tumor--hereditary multiple exostoses]

Hereditary multiple exostoses (HME), also known as osteochondromatosis, is an inherited, autosomal dominant disorder in which multiple osteochondromas develop throughout the skeleton. We present the case of a 17 years old boy diagnosticated with HME with multiple prior orthopedic interventions for upper and lower limbs deformant osteochondromas. He was admitted in our service for a giant osteochondroma localized at the left thoraco-abdominal border arising from C11, C12 ribs, involving the thoracic postero-bazal wall, the abdominal posterior wall and practically the entire left retroperitoneal space. We performed the total resection of this giant tumor (2.6 kg) with postero-inferior thoracic parietectomy (10 to 12 ribs) and abdominal postero-lateral parietectomy followed by the thoraco-abdominal parietal reconstruction with a dual-mesh soft tissue patch, after the high reinsertion of the left diaphragm. The postoperative results were very good from both points of view: esthetical and functional, with preservation of the diaphragm activity and the anatomical reposition of the abdominal viscera. The paper refers to the etiopathogenesis, clinical symptoms, diagnostic, and therapeutic considerations of HME.