Chest wall osteochondroma resection with biologic acellular bovine dermal mesh reconstruction in pediatric hereditary multiple exostoses:A case report and review of literature

BACKGROUND Hereditary multiple exostoses is a rare genetic disorder characterized by the growth of multiple osteochondromas affecting primarily long bones.Chest wall lesions may represent a challenge,particularly in pediatric patients.Pain is a common manifestation.However,life-threatening complications can result from direct involvement of adjacent structures.Surgical resection with appropriate reconstruction is often required.CASE SUMMARY A 5-year-old male who was diagnosed with hereditary multiple exostoses presented with significant pain from a large growing chest wall exostosis lesion.After appropriate preoperative investigations,he underwent surgical resection with reconstruction of his chest wall using a biologic bovine dermal matrix mesh.CONCLUSION Resection of chest wall lesions in children represents a challenge.Preoperative planning to determine the appropriate reconstruction strategy is essential.

Clinical Characteristics of Hereditary Multiple Exostoses: A Retrospective Study of Mainland Chinese Cases in Recent 23 Years

Hereditary multiple exostoses（HME） are an autosomal dominant skeletal disease with wide variations in clinical manifestations among different ethnic groups. This study investigated the epidemiology, clinical presentations, pathogenetic features and treatment strategies of HME in China's Mainland. We searched and reviewed the related cases published since 1990 by searching electronic databases, namely SinoMed database, Wanfang database, CNKI, Web of Science and PubMed as well as Google search engines. A total of 1051 cases of HME（male-to-female ratio 1.5：1） were investigated and the diagnosis was made in 83% before the age of 10 years. Approximately 96% patients had a family history. Long bones, ribs, scapula and pelvis were the frequently affected sites. Most patients were asymptomatic with multiple palpable masses. Common complications included angular deformities, impingement on neighbouring tissues and impaired articular function. Chondrosarcomas transformation occurred in 2% Chinese cases. Among the cases examined, about 18% had mutations in EXT1 and 28% in EXT2. Frameshift, nonsense and missense mutations represented the majority of HME-causing mutations. Diagnosis of HME was made based on the clinical presentations and radiological documentations. Most patients needed no treatment. Surgical treatment was often directed to remove symptomatic exostoses, particularly those of suspected malignancy degeneration, and correction of skeletal deformities. This study shows some variance from current literature regarding other ethnic populations and may provide valuable baseline assessment of the natural history of HME in China's Mainland.

Spontaneous pneumothorax in a 17-year-old male patient with multiple exostoses:A case report and review of the literature

BACKGROUND Multiple exostoses generally develop in the first decade of life.They most frequently arise from the distal femur,proximal tibia,fibula,and proximal humerus.Costal exostoses are rare,contributing to 1%-2% of all exostoses in hereditary multiple exostoses(HME).They are usually asymptomatic,but a few cases have resulted in severe thoracic injuries.Pneumothorax caused by costal exostoses is rare,with only 13 previously reported cases.We report a new case of pneumothorax caused by costal exostoses.CASE SUMMARY A 17-year-old male with HME underwent surgery for removal of exostoses around his right knee.Four months following the operation,he felt chest pain when he was playing the trumpet;however,he did not stop playing for a week.He was referred to our hospital with a chief complaint of chest pain.The computed tomography(CT)scan revealed right pneumothorax and multiple exostoses in his right ribs.The CT scan also revealed visceral pleura thickness and damaged lung tissues facing the exostosis of the seventh rib.We diagnosed that exostosis of the seventh rib induced pneumothorax.Costal exostosis resection was performed by video-assisted thoracoscopic surgery(VATS)2 wk after the onset.The patient’s postoperative course was uneventful,and there was no recurrence of pneumothorax for 2 years.CONCLUSION Costal exostoses causing thoracic injuries should be resected regardless of age.VATS must be considered in cases with apparently benign and relatively small exostoses or HME.

Identification of mutation in a candidate gene for hereditary multiple exostoses type Ⅱ

Objectives To identify possible mutations in our previously cloned candidate gene for hereditary multiple exostoses type Ⅱ (EXT2) in affected members of EXT families so as to confirm that it is the disease causing gene. Methods The mutation was detected first by single strand conformational polymorphism(SSCP) of all coding exons of the candidate gene and then by sequencing analysis. Results After analyzing 37 patients from 20 Chinese EXT families by SSCP and DNA sequencing analysis, one 2 bp insertion mutation was identified in this candidate gene in affected members of an EXT family. This mutation resulted in the frameshift and generated a truncated gene product consisting of 105 amino acids. Conclusions The identification of the mutation in the candidate gene indicates that this novel gene is responsible for EXT2 (one of the disease causing gene of EXT).