Diffuse subependymal periventricular metastases. Report of three cases

Area of Science:

• Neuropathology
• Oncology
• Radiology

Background:

• Cerebral metastases can present with diverse patterns of brain infiltration.
• Small cell lung cancer (SCLC) is known for its aggressive nature and propensity for widespread metastasis.
• Understanding metastatic patterns is crucial for accurate diagnosis and treatment planning.

Observation:

• Three clinicopathologic cases demonstrated extensive diffuse subependymal periventricular spread of cerebral metastases.
• Two cases originated from small cell carcinoma of the lung; the third showed features consistent with neuron-specific enolase-positive, small cell anaplastic carcinoma.
• Minimal involvement of the choroid plexus and leptomeninges was noted, with rare intraparenchymal or superficial cortical nodules.

Findings:

• The primary pattern observed was diffuse subependymal periventricular infiltration, distinguishing it from typical nodular metastases.
• Clinical symptoms were largely nonspecific, though one patient experienced orthostatic hypotension potentially linked to ventricular floor infiltration.
• Cerebrospinal fluid examinations were normal in available cases, highlighting the diagnostic utility of imaging.

Implications:

• This distinct pattern of SCLC brain metastasis requires consideration in differential diagnoses, particularly when imaging shows diffuse subependymal spread.
• Contrast-enhanced computed tomography (CT) scanning was the key diagnostic tool, underscoring its importance in identifying such infiltrative lesions.
• Further research into the mechanisms and clinical significance of this specific metastatic pathway is warranted.