Partially Cystic Lumbar Schwannoma with Atypical Histopathological Features.

Partially Cystic Lumbar Schwannoma with Atypical Histopathological Features.:

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Partially Cystic Lumbar Schwannoma with Atypical Histopathological Features.

World Neurosurg. 2020 Apr 03;:

Authors: Lak AM, Abunimer AM, Segar D, Zaidi HA

Abstract

BACKGROUND: Spinal schwannomas are benign nerve sheath neoplasms which constitute about 30% of extramedullary spinal cord tumors. They are usually small, well-encapsulated tumors with low mitotic activity, and concurrently carry low risk of recurrence. Here, we report a case of atypical histological variant of spinal schwannoma that had higher cellular density, nuclear atypia and lack of encapsulation. To our best knowledge, no such cases of this atypical variant with regards to lumbar spine have been reported in the literature.

CASE REPORT: A 66-year-old male had an incidental left-sided paraspinal mass discovered while undergoing workup for cholecystitis. On examination, the patient was neurologically intact. Imaging revealed the presence of contrast-enhanced, partially cystic mass arising from L3-4 intervertebral foramen and causing left psoas muscle displacement. A minimally invasive left L3-4 posterior extra-cavitary resection was done. Histopathologic examination revealed partly unencapsulated tumor with higher than usual cellular density and nuclear atypia, resulting in a diagnosis of 'atypical schwannoma.' Follow-up imaging at 6 months follow-up showed stable post-surgical changes and residual tumor with no evidence of progression/recurrence.

CONCLUSION: Atypical schwannoma has higher cellular density, nuclear atypia and lack encapsulation. Review of the literature suggests an increased risk of recurrence when compared to typical variants and complete tumor removal should be attempted.

PMID: 32251817 [PubMed - as supplied by publisher]