Intraosseous schwannoma of the humerus: a rarity yet warrants consideration.

Intraosseous schwannoma is extremely rare that it is not often considered among differential diagnosis for an osteolytic lesion, especially in long bones of the extremities. Amounting to less than 0.2% of all primary bone tumours and less than 200 cases reported so far, with only 3 cases involving the humerus, we hereby report the fourth case. In addition to its rarity, this was the only case of an intraosseous schwannoma involving the humerus bone which presented with a pathological fracture in a 45-year-old woman after sustaining a trivial trauma. Radiological examination revealed a geographic type of osteolytic lesion in distal shaft region of the left humerus. Only a histopathological examination helped in revealing and confirming the diagnosis of an intraosseous schwannoma. Treatment of the tumour with complete excision with bone graft reconstruction and osteosynthesis yields good results with very low risk of recurrence.

Kamath J ，Shetty HB ，Madegowda A ，Bhatt AS ... -  《-》

Intraosseous Schwannoma of fibula: A case report.

Ali SM ，Aftab K ，Habib Ul Hassan S ，Anwar Jilani SA ... -  《JOURNAL OF THE PAKISTAN MEDICAL ASSOCIATION》

Intraosseous schwannoma of the proximal humerus with pathologic fracture.

Intraosseous schwannomas are extremely rare in the humerus, and less than five cases have been reported previously in the literature. This is the first report of its origin in the proximal humerus with pathologic fracture. We herein present this case to discuss the reason for its rarity and share our experience of management. A 55-year-old female patient presented with pain in the right shoulder, which was caused by tripping and falling over a board. Radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) showed considerable tumor in proximal humerus, which connected with a fracture. For this suspected tumor, we performed two operations. Pathological examination demonstrated typical picture of a schwannoma, showing whorls and interlacing fascicles of schwannoma spindle cells. Immunohistochemistry, the tumor cells were diffusely positive for S-100 protein, SOX-10 and CD68, while they were completely negative for desmin, DOG-1, AE1/AE3 and P63. The Ki-67 index was about 10%. No mitoses or features of malignancy were identified. The final diagnosis of intraosseous schwannoma was made. The treatment for intraosseous schwannoma with pathologic fracture includes excisional biopsy, curettage, bone allograft, and fracture fixation. The patient recovered well. After the surgery, the patient gradually regained mobility and the pain subsided. There was no recurrence after 6 months of follow-up by X-ray. Although very rare, intraosseous schwannoma should be taken under consideration in the differential diagnosis of benign-appearing osseous tumor in the proximal humerus with pathologic fracture.

Huajun J ，Wei Q ，Yuxuan W ，Jingjing Y ... -  《-》

Recurrent benign solitary intraosseous schwannoma of the tibia.

Ang WM ，Yates P ，Robbins P ，Wood D ... -  《ORTHOPEDICS》

Primary intraosseous hybrid epithelioid schwannoma/perineurioma in the proximal tibia: a case report of benign hybrid neoplasm with local hypercellularity.

Lang Y ，Liu D ，Xiang P ，Wang J ，Li Y ... -  《Diagnostic Pathology》