Lesions of the corpus callosum

Lesions of the corpus callosum are uncommon and arise from multiple different etiologies. The lesions can be classified according to underlying pathophysiology ^4-6.

Neoplasm

Typically, amongst neoplasms, only aggressive lesions can invade the corpus callosum as it is composed of very dense white matter tracts which act as a barrier to tumor spreading ¹.

• anaplastic astrocytoma
• callosal oligodendroglioma
• glioblastoma (butterfly glioma)
• gliomatosis cerebri
• meningioma: secondary involvement from primary falx lesion
• metastasis: rare, mainly from contiguous extension of lesion adjacent to corpus callosum
• primary CNS lymphoma

Vascular

• aneurysm: can occasionally rupture into the corpus callosum
• arteriovenous malformation: arising around the corpus callosum
• cavernous malformation (cavernoma)
• gliosis: secondary to small vessel chronic ischemia, subcortical arteriosclerotic encephalopathy, radiation therapy and normal aging ¹¹; histologically corresponds to subependymal gliosis
  • the subependymal splenium is typically affected with normal aging and after radiation therapy ¹¹
• hypoxic-ischemic encephalopathy: corpus callosum only involved in severe or advanced case
• infarction: rare because of extensive collateral vascular supply, most often seen with emboli, major ischemic stroke, subfalcine herniation with mass effect and vasculitides ³

Infection

• aspergillosis: can involve corpus callosum ⁷
• transient lesions of the splenium: many underlying etiologies including infectious agents
• subacute sclerosing panencephalitis: can involve the corpus callosum in advanced stages ⁸
• tuberculosis: callosal tuberculomas have been reported, although rare ⁹

Demyelination

• acute disseminated encephalomyelitis
• Marchiafava-Bignami disease: demyelination and necrosis, can appear as cystic lesions
• multiple sclerosis
• neuromyelitis optica
• progressive multifocal leukoencephalopathy
• Susac syndrome
• wallerian degeneration

Leukodystrophy

• Krabbe disease
• metachromatic leukodystrophy
• Susac syndrome
• X-Linked adrenoleukodystrophy

Congenital

• agenesis of the corpus callosum
• enlarged perivascular spaces
• tubonodular pericallosal lipoma: associated with dysgenesis of the corpus callosum

Trauma

• diffuse axonal injury

Other

• corpus callosum impingement syndrome
• cytotoxic lesions of the corpus callosum (CLOCCs): many underlying etiologies
• posterior reversible encephalopathy syndrome (PRES): callosal involvement seen in up to 10% of patients, usually with associated parieto-occipital T2-hyperintensities ¹⁰
• post shunt decompression: after placement of ventriculostomy in patients with chronic hydrocephalus