Anaplastic Large Cell Lymphoma of the Brain Mimicking an Extra-Axial Frontal Tumor: A Case Report
- 1Department of Pathology, Mahatma Gandhi Mission's Medical College, Navi Mumbai, IND
Abstract
Primary central nervous system anaplastic large cell lymphoma (PCNS-ALCL) is an extremely rare subtype of T-cell lymphoma with variable clinicoradiological presentation and significant diagnostic challenges. Extra-axial dural-based lesions frequently mimic meningioma radiologically, often leading to delayed diagnosis. We report a case of a 41-year-old female presenting with severe headache followed by sudden-onset altered sensorium. Neuroimaging revealed a lobulated hyperdense extra-axial frontal lesion associated with extensive vasogenic edema, ventricular compression, and marked midline shift suggestive of aggressive intracranial pathology. Emergency surgical excision was performed because of significant mass effect and impending herniation. Histopathological examination demonstrated diffuse infiltration of the brain parenchyma by pleomorphic plasmacytoid tumor cells with marked atypia, brisk mitotic activity, and focal necrosis. Immunohistochemistry showed diffuse positivity for cluster of differentiation (CD)30, leukocyte common antigen (LCA), and epithelial membrane antigen (EMA) with a high Ki-67 proliferative index, while tumor cells were negative for glial fibrillary acidic protein (GFAP), pan-cytokeratin (PanCK), CD20, CD3, CD10, CD138, spalt-like transcription factor 4 (SALL4), and anaplastic lymphoma kinase (ALK)-1. Based on histomorphology and immunophenotypic profile, a final diagnosis of PCNS ALK-negative ALCL was established. This case highlights the importance of considering lymphoma in the differential diagnosis of rapidly progressive extra-axial lesions associated with disproportionate edema and acute neurological deterioration.
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BibTeX
@article{vishwakarma2026anaplastic,
title = {{Anaplastic Large Cell Lymphoma of the Brain Mimicking an Extra-Axial Frontal Tumor: A Case Report}},
author = {Seema V Vishwakarma and Rahul Rajbhar and Shilpi Sahu},
journal = {Cureus},
year = {2026},
month = sep,
doi = {10.7759/cureus.117242},
url = {https://europepmc.org/article/PMC/PMC13722362},
note = {CC BY},
}
RIS
TY - JOUR
TI - Anaplastic Large Cell Lymphoma of the Brain Mimicking an Extra-Axial Frontal Tumor: A Case Report
AU - Seema V Vishwakarma
AU - Rahul Rajbhar
AU - Shilpi Sahu
PY - 2026
DA - 2026/09/30
JO - Cureus
DO - 10.7759/cureus.117242
UR - https://europepmc.org/article/PMC/PMC13722362
AB - Primary central nervous system anaplastic large cell lymphoma (PCNS-ALCL) is an extremely rare subtype of T-cell lymphoma with variable clinicoradiological presentation and significant diagnostic challenges. Extra-axial dural-based lesions frequently mimic meningioma radiologically, often leading to delayed diagnosis. We report a case of a 41-year-old female presenting with severe headache followed by sudden-onset altered sensorium. Neuroimaging revealed a lobulated hyperdense extra-axial frontal lesion associated with extensive vasogenic edema, ventricular compression, and marked midline shift suggestive of aggressive intracranial pathology. Emergency surgical excision was performed because of significant mass effect and impending herniation. Histopathological examination demonstrated diffuse infiltration of the brain parenchyma by pleomorphic plasmacytoid tumor cells with marked atypia, brisk mitotic activity, and focal necrosis. Immunohistochemistry showed diffuse positivity for cluster of differentiation (CD)30, leukocyte common antigen (LCA), and epithelial membrane antigen (EMA) with a high Ki-67 proliferative index, while tumor cells were negative for glial fibrillary acidic protein (GFAP), pan-cytokeratin (PanCK), CD20, CD3, CD10, CD138, spalt-like transcription factor 4 (SALL4), and anaplastic lymphoma kinase (ALK)-1. Based on histomorphology and immunophenotypic profile, a final diagnosis of PCNS ALK-negative ALCL was established. This case highlights the importance of considering lymphoma in the differential diagnosis of rapidly progressive extra-axial lesions associated with disproportionate edema and acute neurological deterioration.
SN - 2168-8184
ER -