BACKGROUND: Intraosseous schwannomas or neurilemomas are rare benign neoplasms. Total resection of the intraosseous schwannoma is considered risky in immunocompromised patients, thus minimally invasive vertebroplasty was conducted in this study.
METHODS: In this case, we presented A 40-year-old male presented with intermittent back pain for the last two years. Imaging and histopathological examination conclude the diagnosis of intraosseous schwannoma. Vertebroplasty was conducted without the resection of the tumor. Excellent pain improvement and functional outcome were reported on one-year follow-up.
UNASSIGNED: Minimally invasive surgery could decrease post-operative pain and morbidity such as atelectasis and venous thrombosis, earlier hospital discharge, and improved cosmetics. We considered the use of minimally invasive vertebroplasty due to HIV infection comorbidities in the subject. Extensive tumor resection in this population could increase the risks of infection significantly thus affecting the outcome of the surgery. The aim of percutaneous vertebroplasty is to increase the stability of the collapsed vertebra and improve the symptoms, especially with severe back pain.
CONCLUSIONS: Intraosseous schwannoma of the vertebrae could be treated effectively with vertebroplasty with excellent pain improvement and functional outcome.

BACKGROUND: The intraosseous schwannoma (IS) is a benign peripheral nerve sheath tumor postulated to arise de novo or from nerve fibers in preexisting nutrient canals. ISs are uncommon and comprise less than 1% of neoplasms originating in bone. We herein present two cases of mandibular schwannomas-the first case was a 66-year-old female with a four-month history of pain and pressure associated with an anterior mandibular radiolucency, and the second case was an asymptomatic 12-year-old female with separate radiolucencies of her mandibular symphysis and right posterior mandible. Incisional biopsies of all three lesions showed a benign spindle cell neoplasm with histologic features of a schwannoma; the tumor cells were strongly reactive for S-100. The patients underwent complete enucleation of their lesions and are without evidence of disease at ten months and five years, respectively.
METHODS: A systematic review was undertaken to evaluate the diagnostic features, treatment, and patient outcomes of gnathic schwannomas.
RESULTS: A total of 93 cases were identified with the following demographic findings: predominance in females (57%); average age of occurrence of 37.3 years (8 to 77 years); mean size of 3.6 cm; and involvement of the mandibular body (37.6%), mandibular body and ramus (18.3%), and anterior mandible (18.3%). The predominant clinical sign was swelling (69.9%), and the most common radiographic presentation was a radiolucency (94.6%) with well-defined borders (72%).
CONCLUSIONS: All cases were treated surgically, with an average follow-up interval of 22.9 months and a recurrence rate of 5.4.

Intraosseous schwannomas are extremely rare and only a few cases involving the proximal phalanx and metacarpal of the hand have been reported. We report a patient with an intraosseous schwannoma of the distal phalanx. Radiographs showed lytic lesions in the bony cortex and enlarged soft shadows of the distal phalanx. The lesion was hyperintense to fat on T2-weighted magnetic resonance imaging (MRI) and strongly enhanced after gadolinium (Gd) administration. Surgical findings revealed that the tumour had developed from the palmar side of the distal phalanx and the medullary cavity was filled with a yellow tumour. The histological diagnosis was schwannoma. A definitive diagnosis of intraosseous schwannoma using radiography is difficult. In our case, a high signal was observed on Gd-enhanced MRI and histological findings showed areas with a high cellular area. Thus, Gd-enhanced MRI may help in the diagnosis of intraosseous schwannomas of the hand. Level of Evidence: Level V (Therapeutic).

Intraosseous schwannomas are rare benign tumors that most often occur at the mandible or sacrum. We present an unusual case of a bilobed schwannoma of the distal humerus with both intraosseous and extraosseous components. The extraosseous component was non-enhancing on initial MRI and enhanced on a subsequent MRI obtained after biopsy. We hypothesize that this change was attributable to decreased intra-tumoral pressure secondary to biopsy-related disruption of the tumor capsule.

Schwannoma is a slow-growing, encapsulated benign tumor of the neuroectodermal origin arising from the perineural Schwann cells. This study aims to elucidate the clinicoradiographical and histopathological features of orofacial schwannomas through a case series of seven cases. The patients\' aged ranged from 13 to 45 years, with a male predilection in the ratio of 5:2. One intraosseous case presented as a radiolucent lesion. All the cases exhibited Antoni A and Antoni B type of microscopic patterns in varying amounts. One case of ancient schwannoma showed degenerative features. The tumor cells showed diffuse positive immunohistochemical reaction for S-100 protein. Our study suggests that intraosseous schwannoma should be considered in the differential diagnosis of the intraosseous jaw lesions. Histopathologically, it is important to recognize the findings of ancient schwannoma and to avoid misdiagnosing it as a malignant lesion.

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.
METHODS: 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.

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.

Primary tumors of sacrum are rarely seen, and the differential diagnosis is extensive, such as chordomas, giant cell tumors, and schwannomas. Sacral intraosseous schwannomas (IOSs) are very rare and encompass approximately 1%-5% of all spinal schwannomas. Melanotic schwannomas (MSs) are categorized as an unusual variant of benign schwannomas; however, they sometimes follow a malignant course. The authors present a case of MS with intraosseous extension into sacrum in a 48-year-old male arising from the left S2 nerve root. Magnetic resonance imaging (MRI) and computed tomography (CT) scan demonstrated a destructive mass in the sacrum. He was made a diagnosis with MS by 18F-fluoro-deoxy-glucose positron-emission-tomography (18F-FDG PET) and open biopsy. The tumor was blackish-colored and vascular-rich fragile tumor covered by fibrous capsule. The floor of the tumor was not encapsulated and invading into the sacral bone. Total removal of the tumor together with the left S2 nerve of origin via posterior approach was achieved. The patient made dramatic recovery of neurological symptoms and tumor recurrence is not seen for 6-month follow-up period. MS is a benign tumor with potential for aggressive behavior and capacity to metastasize. Therefore, total removal of the tumor and careful postoperative follow-up are recommended. Postoperative spinopelvic stability also needs to be taken into consideration. The authors discuss our successful management with a focus on diagnostic process, surgical planning, and histological consideration to provide the most up-to-date guidance on managing this challenging tumor.

Schwannomatosis is a recently recognized distinct form of neurofibromatosis (NF). It is a rare condition, the incidence of which varies between 1/400,000 and 1/1.7 million. An important feature of schwannomatosis is the presence of multiple intracranial, spinal, and peripheral schwannomas in the absence of acoustic neuromas. Schwannomatosis presenting with intraosseous schwannoma of the mandible is even rarer, and only a few cases have been reported. It usually affects individuals in the third to fifth decade of life. Usually, it is sporadic in origin, but in 20% of patients, it can be familial. As a diagnostic criterion, NF2 gene is not involved in schwannomatosis. We report a case of a 48-year-old male presenting with facial pain and difficulty in chewing, and subsequent development of spastic paraplegia. Magnetic resonance imaging scan of head and neck revealed mass lesion involving infratemporal region on the left side, intraosseous lesion of the mandible, and multiple mass lesions in the neck. Acoustic nerves were not involved. Mutagen-induced chromosome sensitivity analysis test suggested no predisposition for malignancy. His clinical features are suggestive of schwannomatosis, which is a recently recognized distinct form of NF.

BACKGROUND: Intraosseous petrous apex schwannomas are an exceedingly rare entity; little is known about their epidemiology, natural history, and postoperative outcomes.
METHODS: Here, we present the fourth known case of a primary intraosseous schwannoma of the petrous apex: a 68-year-old woman presenting with diplopia, facial numbness, progressive intermittent vertigo, tinnitus, diminished hearing, and ataxia. She underwent a transtemporal approach for subtotal resection of the tumor with subsequent stereotactic radiosurgery.
CONCLUSIONS: Our 2-year follow-up demonstrates slow growth and success of multimodal management in the treatment of these tumors. We review the 3 prior reports of petrous apex schwannomas and identify unifying radiographic and clinical characteristics to aid future diagnostic considerations of lesions of the petrous apex.