Melanotic schwannoma of spine: Illustration of two cases with diverse clinical presentation and outcome

Abstract

Melanotic schwannomas (MS) are rare variants of schwannomas the occurrence of which is described in case reports only. They usually arise from posterior spinal nerve roots and less commonly from other cells of neural crest origin. Although they are relatively benign tumors in young, aggressive behavior is reported. They occur as isolated tumors or as part of a syndrome named Carney complex. We try to describe the pathology, diagnosis, management, and prognosis of MSs in two different cases: one cervical intramedullary with no recurrence on 5-year follow-up and the other one extramedullary in lumbar region with early recurrence and aggressive course. A brief review of literature is done.

T2 Hypointense Schwannoma Masquerading As A Vascular Lesion: A Case Report

“…9 Largely hypointense schwannomas have been described, though reports are rare and T2 hypointensity is more commonly seen in melanotic intramedullary schwannomas, as opposed to the extramedullary lesion in this patient. 10-12 Although the T2 hyperintensity of schwannomas may be heterogenous, 13 this lesion did not demonstrate any significant hyperintensity, and thus workup for a vascular lesion was initiated. In contrast, this patient’s lesion demonstrated numerous features consistent with a thrombosed varix.…”

Post-operative Stereotactic Radiosurgery of Malignant Melanotic Schwannoma

“…The role of radiotherapy after margin-positive surgical resection is controversial given the unclear efficacy, particularly given the discordance of early and recent reports on the malignant potential of melanotic schwannomas. In addition, as these patients are typically young [ 10 ], there is a concern for late toxicity of radiotherapy (including secondary malignancy, or infertility if radiating in the pelvis). Even if radiation is recommended, the optimal dose is unclear, with published reports ranging from 50 to 60 Gy over five to six weeks.…”

“…Given the unpredictable biologic behavior and initial reports of benign behavior, unclear efficacy of radiotherapy, and typically young age of these patients (median age in the fourth decade) [ 10 ], there are concerns with using adjuvant external beam radiotherapy. Stereotactic radiosurgery (SRS), which uses ablative dosing with rapid dose fall-off to spare adjacent normal tissues, is commonly used for classic schwannomas [ 11 ].…”

An Overview of Central Nervous System Tumours

“…Melanotic schwannomas (MSs) are rare circumscribed nerve sheath tumours of melanin producing schwann cells that accounts for approximately 1% of all nerve sheath tumours [182,183]. They are considered as tumours of the young occurring in patients between the ages of 10-90 years with peak incidence between the fourth and fifth decade of life, with no sex predilection [184,185].…”