No, a lacunar infarct is NOT a meningioma—they are completely different pathological entities
A lacunar infarct is a small ischemic stroke caused by occlusion of penetrating arteries in the brain, while a meningioma is a tumor arising from arachnoid cells in the meninges. These are fundamentally distinct conditions with different etiologies, pathophysiology, and management approaches.
Lacunar Infarct: Definition and Characteristics
Lacunar infarcts are small subcortical ischemic lesions measuring less than 1 cm in diameter (some sources use <1.5 cm), located specifically in the basal ganglia, brain stem, or deep white matter—never in the cerebral cortex 1, 2.
These lesions result from occlusion of single penetrating arteries (100-400 micrometers in diameter) that branch at right angles from major cerebral vessels 3.
The underlying pathology involves small vessel disease, most commonly microatheroma, lipohyalinosis, or fibrinoid necrosis—not tumor growth 3, 4.
On imaging, lacunar infarcts appear as cystic lesions that represent areas of prior ischemic injury 1.
Meningioma: Definition and Characteristics
Meningiomas are tumors arising from arachnoid cells present in the meninges and can develop anywhere meninges exist 1, 5.
On MRI, meningiomas typically show homogeneous dural-based enhancement with a characteristic "dural tail sign"—features completely absent in lacunar infarcts 5, 6.
Meningiomas are extra-axial masses that compress brain tissue from outside, whereas lacunar infarcts are intra-axial lesions within the brain parenchyma itself 1, 5.
Histologically, meningiomas show syncytial growth patterns, meningothelial whorls, and psammoma bodies, and stain positively for epithelial membrane antigen—completely different from the cystic cavitation seen in old lacunar infarcts 1.
Critical Diagnostic Distinctions
Lacunar infarcts are vascular lesions associated with hypertension and diabetes, while meningiomas are neoplastic lesions with no direct relationship to vascular risk factors 3, 4, 1.
The clinical presentations differ markedly: lacunar infarcts present acutely with classical lacunar syndromes (pure motor hemiparesis, pure sensory syndrome), while meningiomas typically cause gradually progressive symptoms from mass effect 2, 3, 1.
Treatment approaches are entirely different: lacunar infarcts require antiplatelet therapy and vascular risk factor modification 2, 4, while meningiomas require surgical resection or radiation therapy 5.
Common Pitfall to Avoid
The only scenario where confusion might arise is the extremely rare case of a meningioma causing cerebral infarction by encasing and occluding cerebral arteries 7. However, even in such cases, the meningioma and the resulting infarct remain distinct entities—the tumor causes the stroke but is not itself the infarct 7.
When evaluating brain imaging showing multiple lacunar infarcts, clinicians should not mistake these for tumors; the presence of multiple small cystic lesions in typical locations (basal ganglia, deep white matter) with associated white matter disease points to small vessel cerebrovascular disease, not neoplasia 1.