Intraosseous schwannoma of inferior pubic ramus – A rare benign osseous neoplasm

Intraosseous schwannomas are a very rare subgroup of schwannomas. They account for <1% of all primary bone neoplasms. The mandible is the most commonly involved bone followed by the sacrum. We herein report a case of intraosseous schwannoma involving the inferior ramus and body of the pubic bone in a 43-year-old male who presented with a swelling in the right groin. On radiographs and computed tomography, it appeared as a mildly expansile, lytic, multiloculated lesion in the right pubic bone with a narrow zone of transition, sclerotic margins with areas of cortical breach, and a significant intra and extrapelvic soft-tissue component which did not show any areas of calcification. On magnetic resonance imaging, it appeared isointense to skeletal muscle on T1-weighted images, mildly hyperintense on T2-weighted images, and markedly hyperintense on short-tau inversion recovery images. The differentials considered on imaging were chondroid neoplasms such as chondromyxoid fibroma or low-grade chondrosarcoma, giant cell tumor, and plasmacytoma. However, biopsy and histopathology revealed an intraosseous schwannoma. The patient was operated and the lesion was excised in toto. Intraoperatively, the origin of the lesion was identified as the right obturator nerve. Post-operative, the patient recovery was uneventful and he was discharged.

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.

Intraosseous schwannoma of the proximal humerus with pathologic fracture

Background 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. Case presentation 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. Conclusions 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.

First-ever intraosseous ancient schwannoma of the proximal ulna successfully treated using the cement technique

Schwannoma or neurilemmoma is a common soft tissue neoplasm arising from the neural sheath of Schwann cells. However, intraosseous schwannoma is rare, accounting for less than 0.2% of primary bone tumours. Several variants of schwannoma have been reported; among them, intraosseous schwannoma with ancient change is extremely rare. This current report presents an extremely rare case of ancient intraosseous neurilemmoma. The patient presented with right elbow pain and disability. A radiolucent, well-defined, lobulated lesion with a thin sclerotic rim in the proximal ulnar metaphysis that had caused a pathological fracture was noted. The mass was surgically excised using marginal resection and bone curettage was undertaken. The bone deficit was grafted with hydroxyapatite and β-tricalcium phosphate and augmented with bone cement. There were no signs of any recurrence after 3 years. This is the first case of an ancient intraosseous schwannoma of the proximal ulna. Although rare, intraosseous schwannoma should be considered in the differential diagnosis of radiographically benign-appearing osseous tumours in the bone. The cement technique is recommended for the treatment of intraosseous schwannoma.

Spinal Intraosseus Schwannoma: A Case Report

Introduction: Schwannomas are the most frequent extramedullary intradural spinal tumors, accounting for approximately 24% of all nerve sheath tumors in adults. In a lower percentage of cases they may be extradural or transdural (1-19%). Intramedullary schwannomas and intraosseous schwannoma are quite rare tumors representing. Case Description: A 74-year-old woman presented intense low back pain for a few months, associated with left cruralgia and dysesthesia spread to both lower limbs. Magnetic resonance and computed tomography examination demonstrated an extramedullary intradural osteolytic lesion located in the posterior part of the vertebral body and pedicles of L1. The patient underwent a first surgery 4 years earlier with complete removal of the tumor but after about two years she had a recurrence. She was then subjected to a new intervention of decompression, removal of the tumor and arthrodesis. The histological findings were compatible with a classical schwannoma characterized by intraosseous growth and multifocal bone infiltration. Conclusion: We reported a rare case of intraosseous schwannoma presenting as a recurrence four years after radical surgical removal of a classic lumbar schwannoma. Only 25 cases of these tumors have been previously reported and none of them as an intraosseous recurrence.

Intraosseous schwannoma of the glenoid: case report and literature review

Intraosseous schwannomas represent an extremely rare subgroup of schwannomas, accounting for <1% of all primary bone tumors. They mostly occur in the mandible, the maxilla, the sacrum, and they are also seen in long bones. We herein report a rare presentation of an intraosseous schwannoma in the glenoid of a 49-year-old patient. She complained of shoulder pain and was referred to the orthopaedic oncologist after detection of a suspicious lesion on imaging. Biopsy revealed benign spindle cells and immunohistochemistry was positive for S100. Because of the rarity of these intraosseous schwannomas it is important to recognize their radiological and histological features and make a differential diagnosis with other lytic tumors. Only if these characteristics are recognized, correct treatment can be given with definite curettage and bone grafting and correct follow-up with avoidance of unnecessary adjuvant therapy.

A Rare Primary Intraosseous Schwannoma of the Tibia

Background: Primary intraosseous schwannoma is a rare benign tumor derived from schwanncells that cover myelinated nerve fibers, accounting for less than 0.2% of all primary bone tumors. Because of its rarity, the new World Health Organization classification of bone tumors has deleted it.Case presentation: A 29-year-old woman presented with a history of intermittent pain on her right ankle over three years. Radiological examination revealed a multilocular cystic and lytic lesion in the distal tibia. Histologically, the tumor was composed of spindle shaped cells, similar to soft tissue neurilemmoma. The patient underwent a surgical resection of the intraosseous lesion. After a 38-month follow-up, the symptoms were significantly relieved and there was no clinical or radiological recurrence.Conclusion: Primary intraosseous schwannoma is a rare benign bone tumor. The pathologists should be aware of the incidence of the tumor, although WHO has deleted it.