Siblings with vascular involvement associated with hereditary multiples exostosis

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.

Venous malformation may be a feature of EXT1-related hereditary multiple exostoses: A report of two unrelated probands

Hereditary multiple exostoses (HME), also known as hereditary multiple osteochondroma (HMO), is an autosomal dominant disorder caused by pathogenic variants in exostosin-1 or -2 (EXT1 or EXT2). It is characterized by the formation of multiple benign growing osteochondromas (exostoses) that most commonly affect the long bones; however, it may also occur throughout the body. Although many of these lesions are clinically asymptomatic, some can lead to chronic pain and skeletal deformities and interfere with adjacent neurovascular structures. Here, we report two unrelated probands that presented with a clinical and molecular diagnosis of HME with venous malformation, a clinical feature not previously reported in individuals with HME.

Hereditary multiple exostoses as a novel cause of bilateral popliteal artery aneurysms in the elderly

Hereditary multiple exostoses (HME) is a genetic condition characterized by the development of multiple osteochondromas during childhood and adolescence. On rare occasions, these bony tumors can be associated with vascular injury, most commonly involving the popliteal artery. Such patients typically present with vascular complications in adolescence and young adulthood. We report an autopsy study of an elderly man who presented with bilateral popliteal artery pseudoaneurysms in the setting of HME at age 81. This is the oldest patient presenting with a vascular complication due to HME reported to date, as well as the only known case of bilateral popliteal pseudoaneurysms caused by HME. This is also the only autopsy study of this vascular complication so far reported. Our case illustrates that vascular complications from HME can occur even in the elderly, and may show bilateral involvement.

Small sharp exostosis tip in solitary osteochondroma causing intermittent knee pain due to pseudoaneurysm

BACKGROUND

Complications of solitary or multiple osteochondromas are rare but have been reported in recent literature. Most reported complications arose in patients with multiple and/or sizable osteochondromas.

CASE PRESENTATION

A 22-year-old, female, Caucasian patient with obesity presented with intermittent knee pain and hematoma of the right calf. The MRI depicted a small, sharp exostosis tip of the dorsal distal femur with a surrounding soft-tissue mass. After profuse bleeding occurred during biopsy of the soft tissue mass, angiography revealed a pseudoaneurysm of the right popliteal artery. In a second-stage surgery the exostosis tip and pseudoaneurysm were resected.

CONCLUSION

Complications can also arise in small, seemingly harmless osteochondromas. Surgical resection should be considered as a preventive measure when exostoses form sharp tips close to neurovascular structures regardless of total osteochondroma size.

Low yield of genetic testing for known vascular connective tissue disorders in patients with fibromuscular dysplasia

Patients with fibromuscular dysplasia (FMD) may have clinical features consistent with Mendelian vascular connective tissue disorders. The yield of genetic testing for these disorders among patients with FMD has not been determined. A total of 216 consecutive patients with FMD were identified. Clinical characteristics were collected and genetic test results reviewed for abnormalities in the following genes: transforming growth factor-β receptor 1 and 2 (TGFβR1 and TGFβR2), collagen 3A1, fibrillin-1, smooth muscle α-actin 2, and SMAD3. A total of 63 patients (63/216; 29.2%) were referred for genetic counseling with testing performed in 35 (35/63; 55.6%). The percentage of patients with a history of arterial or aortic dissection, history of aortic aneurysm, systemic features of a connective tissue disorder, and a family history of sudden death was significantly larger in the group that underwent genetic testing (62.9% vs 18.2%, p < 0.001; 8.6% vs 1.7%, p = 0.02; 51.4% vs 17.1%, p < 0.001; and 42.9% vs 22.7%, p = 0.04, respectively). Two patients were found to have distinct variants in the TGFβR1 gene (c.611 C>T, p.Thr204lle and c.1285 T>C, p.Tyr429His). The yield of genetic testing for vascular connective tissue disorders was low in a high-risk subset of FMD patients. However, two patients with a similar phenotype had novel and distinct variants in the TGFβR1 gene, a finding which merits further investigation.