Brain metastases from undiagnosed systemic neoplasms

Area of Science:

• Neurology
• Oncology
• Radiology

Background:

• Brain metastases are a significant complication of cancer, often presenting with undiagnosed primary neoplasms.
• Understanding the origin and characteristics of brain metastases is crucial for patient management and prognosis.

Purpose of the Study:

• To retrospectively analyze the characteristics of symptomatic brain metastases in patients with unknown primary cancers.
• To identify the most common primary cancer types and evaluate the diagnostic yield of various imaging modalities.

Main Methods:

• Retrospective study of 56 patients with symptomatic brain metastasis and undiagnosed primary neoplasm.
• Analysis of metastasis location, frequency (solitary vs. multiple), and primary cancer origins.
• Evaluation of diagnostic imaging tests, including chest roentgenograms and computed tomography (CT) scans of the chest, abdomen, and pelvis.

Main Results:

• Lung cancer was the most frequent primary source (68%), particularly adenocarcinoma and small-cell types.
• Metastases were equally solitary (57%) and multiple (43%), with parietal lobe involvement most common (67%).
• Diagnostic evaluation identified the primary cancer in 84% of patients; chest imaging demonstrated the highest diagnostic yield.

Conclusions:

• Lung cancer is the predominant primary malignancy in patients with brain metastases of unknown origin.
• Tailored diagnostic strategies, prioritizing chest imaging, are recommended for cost-effectiveness and improved detection rates.
• Survival rates at 6 and 12 months were 55% and 13%, respectively, with no significant difference between cerebellar and noncerebellar metastases.