Intracranial epithelioid schwannoma - a case report

Epithelioid schwannoma: imaging findings on radiographs, MRI, and ultrasound

Epithelioid schwannoma is an uncommon benign peripheral nerve sheath tumor, with distinct morphological and pathological features. To our knowledge, the imaging features of epithelioid schwannoma have not been described. In this case report, we describe the imaging findings of a pathologically proven case of epithelioid schwannoma presenting as a slowly growing painless mass near the ankle. The MR imaging signs commonly associated with conventional schwannoma were absent. On correlative radiographs, there were intra-tumoral calcifications. Radiographs are an essential tool in the imaging evaluation of soft-tissue masses. Knowledge of soft-tissue tumor types that can be associated with intra-tumoral calcifications is helpful in honing the differential diagnosis.

Five-Year-Old Boy With Behavioral Changes and Papilledema

A 5-year-old boy had initial symptoms of behavioral changes, nausea, vomiting, headache, weight loss, and progressive vision failure. Brain MRI revealed abnormal signal intensity in both optic nerves, the optic chiasm, the right medial temporal lobe, and tissues surrounding the right supraclinoid internal carotid artery with associated leptomeningeal and spinal cord enhancement. After nondiagnostic dural and spinal arachnoid biopsies, a temporal lobe biopsy was diagnostic for a rare malignant peripheral nerve sheath tumor.

Schwannome épithélioïde du nerf acoustique : une observation

Epithelioid schwannomas mainly affect peripheral nerves and are frequently malignant. They are rarely encountered intracranially. Only five cases involving the eight nerve have been reported in the literature. We report the sixth case of epithelioid schwannoma of the acoustic nerve diagnosed in a 57 year-old woman operated for neurinoma of the right cerebellopontine angle. The patient was readmitted for local recurrence nine months later. Histologically, the tumour was composed of round or polygonal atypic cells associated with spindle cell areas. In our case, the local recurrence, nuclear pleomorphism and especially the high percentage of positive cells with p53 (80%) and Ki67 (30%) antibodies support the aggressive nature of the lesion.

Malignant epithelioid cranial nerve sheath tumor: case report of a radiation response

Malignant epithelioid nerve sheath tumors (MESs) especially those involving intracranial cranial nerves are rare and thought to be radioresistant. We report a case of a MES involving the Vth and VIIth cranial nerves responsive to radiotherapy. A 41-year-old man with progressive left facial weakness underwent an MRI that disclosed an enhancing lesion involving both V3 cranial nerve and the distal VIIth nerve. Biopsy confirmed a malignant epithelioid schwannoma. The tumor was resected but residual tumor was present at the cut end of the infraorbital nerve, within the oral cavity and at the brainstem. Positive excision margins were irradiated to 60 Gy/30 fractions by a wedge pair technique extending from the inferior orbit to C2. Tumor was controlled for 38 months and then radiographic recurrence was resected from the infratemporal fossa outside the irradiated field.A new primary MES tumor developed at 69 months at the C1/C2 root levels at the lower edge of the previously irradiated field. It was subtotally resected but by 77 months residual tumor had grown inferiorly down to C5 so this area was re-irradiated with a complicated 7-field approach to spare spinal cord. Initially the tumor responded but ultimately progressed posteriorly where radiation dose was limited by spinal cord tolerance. New involvement of the Xth cranial nerve was noted. The patient expired from brainstem compression 7 years after initial radiotherapy. The long-term control of the original tumor despite positive margins argues for the use of radiotherapy in the treatment of these tumors.

Epithelioid Malignant Peripheral Nerve Sheath Tumor in the Infraorbital Nerve

Epithelioid malignant peripheral nerve sheath tumors are rarely found in cranial nerves. This report describes one such tumor originating from the infraorbital nerve in a 55-year-old man who presented with diplopia and right cheek numbness. Imaging showed a mass along the floor of the right orbit, which was excised. Histology suggested melanoma or carcinoma. Immunohistochemical staining was positive for S-100 and negative for HMB-45 and cytokeratin. Four other cases from the literature involving cranial nerves are discussed.