Primary malignant lymphoma of the trigeminal region treated with rapid infusion of high-dose MTX and radiation: case report and review of the literature

BACKGROUND

Extra-axial primary CNS lymphoma, considered rare, mainly arise in the white matter of the brain. Though the tumor responds well to radiation and chemotherapy, the prognosis of primary CNS lymphoma remains poor. We report a case of primary lymphoma of Meckel's cave mimicking a trigeminal schwannoma radiographically, which achieved complete remission through use of rapid high-dose MTX therapy and radiation therapy.

CASE DESCRIPTION

The patient, a 55-year-old Japanese male, presented left trigeminal neuralgia. Magnetic resonance imaging (MRI) revealed a mass lesion in the left side of Meckel's cave, with extension into the cerebellopontine angle and the infratemporal fossa through the foramen ovale, suggesting trigeminal schwannoma. However, the patient suffered radiologically inexplicable progressive cranial nerve palsy, which suggested malignant disease. MRI and CSF disclosed malignant tumor dissemination; biopsy revealed malignant lymphoma. The treatment, composed of the rapid infusion of high-dose MTX and whole brain and spine radiation, resulted in complete remission.

CONCLUSIONS

This case, which included atypical presentation of malignant lymphoma, illustrates the importance of including malignant lymphoma in the differential diagnosis of CP-angle and Meckel's cave tumor. The results also confirmed the usefulness of combined rapid high-dose MTX therapy and radiation.

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.

Ocular neuromyotonia with spastic lid closure

Ocular neuromyotonia is characterized by tonic spasms of extraocular muscles evoked by eccentric gaze that induces transient strabismus and diplopia. We report the case of a 70-year-old woman who initially presented with unilateral deficits in fifth and sixth cranial nerve functions attributed to a fifth cranial nerve schwannoma. After radiation treatment, she developed neuromyotonia and synkinesis of the ipsilateral third cranial nerve. During the attacks of neuromyotonia, the left eyelids were often spastically closed, a phenomenon not previously reported. The ocular neuromyotonia regressed spontaneously within 3 years, but components of the synkinesis persisted. Ephaptic transmission in a damaged third cranial nerve may be responsible for the neuromyotonia and synkinesis. Synkinesis is a more enduring manifestation.

Clavicular metastasis from malignant trigeminal schwannoma

Extracranial metastasis arising from primary intracranial malignant tumours are rare. Cases documented have arisen from tumours arising from glial cells or from undifferentiated neurons. Extracranial deposits from intracranial malignant nerve sheath tumours have not been documented. This case report shows histological similarity - rhabdomyoblastic differentiation in a malignant neoplasm in the clavicle similar to that seen in a malignant trigeminal schwannoma operated earlier. Detailed immunohistochemistry confirmed similarity in histogenesis confirming that the clavicular deposit was a secondary arising from the malignant trigeminal schwanoma.

Trigeminal neuropathy in vestibular schwannoma: a treatment algorithm to avoid long-term morbidity

BACKGROUND

Trigeminal neuropathy (TGN) can occur as a presenting feature of vestibular schwannoma (VS) or as an adverse effect of radiosurgery. This study was designed to evaluate a treatment algorithm for presenting symptoms of TGN in patients with VS, and a new radiosurgery dosimetric tolerance to avoid TGN after treatment. Outcome was measured after microsurgery (MS), stereotactic radiosurgery (SRS), hypofractionated stereotactic radiotherapy (HSRT), and fractionated radiotherapy (FRT).

METHODS

A prospectively held VS database was retrospectively analysed from 2011 to 2016 at a tertiary university hospital. All patients who underwent MS from 2011 and all patients who underwent radiotherapy (SRS, HSRT, FRT) from 2015 were studied. Patients on surveillance and neurofibromatosis type 2 patients were not included. Patient demographic data, tumour characteristics, presenting symptoms, and post-treatment outcomes were analysed.

RESULTS

Eighty-eight patients were included in the study (43 microsurgery, 45 radiotherapy). Twenty-seven (31%) patients presented with TGN symptoms. The median age of patients included was 56.5 (range 6-72 years), with a median follow-up for MS and SRS of 38 and 20 months, respectively (range 10-80 months). All 27 patients with TGN were offered MS as per protocol. Three patients declined, or were not fit for surgery, and received FRT. Complete resolution of TGN symptoms was achieved in all 24 patients who underwent MS and 33% (1/3) of patients with FRT. Eleven patients experienced transient post-operative complications (pseudomeningocele (6), meningitis (3), venous sinus thrombosis, cerebellar haemorrhagic contusion, and posterior fossa haematoma). Of the 45 patients in the radiotherapy cohort, 36 were suitable for SRS, of which 30 patients who met the dose-volume constraints for trigeminal nerve underwent single-fraction SRS and 6 patients who did not meet the constraints received HSRT. Nine patients (20%) received FRT including three patients with pre-treatment TGN. None of the patients developed new TGN symptoms following SRS or HSRT.

CONCLUSIONS

Our algorithm to select the optimal treatment modality appears to achieve comparable or better long-term outcome. Microsurgical resection in our cohort resulted in complete resolution of symptoms in all patients. None of our SRS- or HSRT-treated patients developed TGN during the follow-up period. The adherence to strict trigeminal nerve dose-volume constraints for SRS remains critical to minimise TGN post treatment. Fractionated radiotherapy is an alternative for patients who refuse surgery or those who are unfit for surgery.

Deceptive Mimics of Trigeminal Schwannoma: Be Careful with Primary Radiosurgery

Trigeminal schwannomas are rare lesions centered on the trigeminal ganglion at Meckel?s cave. The complexity and morbidity of surgery for these lesions have allowed stereotactic radiosurgery (SRS) to emerge as a safe and viable option for treatment. Various other lesions at this location must alert one to consider an alternative diagnosis before upfront SRS without histopathological correlation. We present three patients with trigeminal neuropathy with imaging suggesting trigeminal schwannoma. Primary clinicians recommended primary radiosurgery to these patients based on radiological diagnosis. Upon further evaluation and clinical suspicion, we established alternate diagnoses of non-Hodgkin's lymphoma, lepromatous trigeminal nerve involvement, and Aspergillosis involving the Meckel's cave in three cases. Each patient received appropriate treatment instead of SRS. SRS is one of the treatment options for trigeminal schwannomas. No neurosurgical ailment should be treated on its face value with primary SRS, but it must be carefully evaluated on a clinicoradiological profile. Upfront, primary SRS may be counterproductive or detrimental for inflammatory or infectious pathologies, attracting complications.

Trigeminal malignant peripheral nerve-sheath tumor: Systematic review, and case report treated by proton-beam therapy

BACKGROUND

Malignant peripheral nerve-sheath tumor (MPNST) is rare, occurring in approximately 0.001% of the general population. Cases involving cranial nerves, and particularly the trigeminal nerve (V), are exceptionally rare, with only 36 cases reported in a literature review in 2013. Standardized treatment and follow-up protocols are lacking. Here, we present a case of MPNST of the trigeminal nerve, provide a review of all cases described in the literature, and discuss treatment, surgical approach, recurrence rate, follow-up time and prognosis.

METHODS

Based on PRISMA guidelines, we reviewed all cases of trigeminal MPNST published between 1950 and September 2023. We analyzed risk factors for recurrence. And we report the case of a patient with trigeminal MPNST admitted to our hospital.

RESULTS

The literature review retrieved 39 relevant studies, reporting 48 cases. Patient age ranged from 4 to 71 years, for a mean 44.4 ± 17 years. The male:female ratio was 3.8:1. Most cases developed sporadically; 1 patient had neurofibromatosis type 1 and 1 had type 2. Surgery was the first-line treatment (85%), and radiotherapy was often included as adjuvant (65%). During a mean follow-up of 23.1 ± 24.4 months, fatal outcomes occurred in approximately 30% of patients. Only 1 case of systemic metastasis was reported. The only prognostic factor significantly associated with a lower rate of recurrence was complete surgical resection (p = 0.0035).

CONCLUSION

Cranial nerve MPNST is extremely rare, and trigeminal MPNST is even rarer. Treatment corresponds to current recommendations for intracranial MPNST, in which radical resection with adjuvant radiotherapy under stereotactic conditions results in the best outcome. Because of the high risk of recurrence, especially in case of incomplete resection, close follow-up is mandatory. Proton-beam therapy could be an interesting alternative adjuvant therapy after surgery.