Intraosseous Petrous Apex Schwannoma: Case Report and Review of Literature

Intraosseous Schwannoma of the Frontal Bone: A Case Report and Review of the Literature

Intraosseous schwannoma is a rare diagnosis, particularly so in the skull. Accordingly, little data exists to unify common features of this disease. Here, we present the fourth known case of a primary intraosseous schwannoma of the frontal bone: a 46-year-old male with severe, progressive headache and an osteolytic frontal bone lesion. Gross total resection of the lesion was performed with excellent clinical outcome. Histological analysis confirmed the diagnosis. The limited existing literature on this topic was reviewed to identify emerging trends surrounding presenting symptoms and treatment. Early literature suggests symptoms are often nonspecific, except for lesions of the petrous apex. No cases of recurrence have been demonstrated after gross total resection, though incomplete resection has been associated with recurrence. This diagnosis appears to be becoming a more often-considered differential for osteolytic, expansile skull lesions.

Successful management of a rare radius schwannoma mimicking malignant bone tumors: A case report and literature review

Background

Schwannomas are benign tumors originating from Schwann cells, frequently occurring in the spinal cord and peripheral nerves. Intraosseous schwannomas, a rare subset, account for approximately 0.2% of schwannomas. Intraosseous schwannomas commonly impinge the mandible, followed by the sacrum and the spine. By far, only three cases of radius intraosseous schwannomas have been reported in PubMed. The tumor was treated differently in all three cases, resulting in different outcomes.

Case presentation

A 29-year-old male construction engineer who complained of a painless mass on the radial aspect of the right forearm was diagnosed with an intraosseous schwannoma of the radius based on radiography, three-dimensional computed tomography reconstruction, magnetic resonance imaging, pathological examination, and immunohistochemistry. A different surgical approach was employed to reconstruct the radial graft defect using bone microrepair techniques, resulting in more reliable bone healing and early functional recovery. Meanwhile, no clinical and radiographic findings suggestive of recurrence were observed at the 12-month follow-up.

Conclusion

Vascularized bone flap transplantation combined with three-dimensional imaging reconstruction planning might yield better results for repairing small segmental bone defects of the radius caused by intraosseous schwannomas.

Intraosseous schwannoma in the clivus mimicking chordoma treated with endoscopic endonasal surgery: A case report

Background:

Intraosseous schwannomas are extremely rare and they have not yet been reported to occur in the clivus. We report a schwannoma in the clivus mimicking chordoma and review intraosseous schwannomas of the skull.

Case Description:

A 62-year-old man presented with gradually worsening hoarseness with dysphagia and atrophy of the left tongue, trapezius muscle, and sternocleidomastoid muscle. Magnetic resonance imaging showed that the tumor was mainly located in the clivus, and a computed tomography (CT) scan revealed an osteolytic lesion with expansion of the clivus and preservation of the bony cortex. Endoscopic endonasal surgery was performed to diagnose and treat symptoms. The tumor was subtotally removed without any complications. The histopathological findings revealed typical schwannoma, which showed Antoni A and Antoni B patterns positive for S100 protein. Based on the preoperative imaging, intraoperative and histopathological findings, the tumor was considered to be an intraosseous schwannoma in the clivus, and no recurrence was observed after 1 year of postoperative follow-up.

Conclusion:

Even though the intraosseous schwannoma in the clivus is uncommon, it should be considered as a differential diagnosis if an expansive lesion without destruction of the cortical bone is shown on CT as well as iso-hyperintensity on T2-weighted magnetic resonance imaging.