To B(iopsy) or not to B(iopsy)

Area of Science:

• Neuro-oncology
• Thoracic Oncology
• Diagnostic Imaging

Background:

• Metastatic disease evaluation often omits biopsy for central nervous system (CNS) lesions per established guidelines.
• Non-small cell lung cancer (NSCLC) with suspected CNS metastasis is typically treated based on imaging findings.

Observation:

• A patient with NSCLC and presumed CNS metastasis presented with new motor deficits after stereotactic radiosurgery (SRS).
• Imaging revealed disease progression in the previously radiated area.

Findings:

• Craniotomy and tumor resection uncovered a second primary CNS tumor, not a metastasis.
• The patient was downstaged from Stage IV to Stage IIB lung cancer due to the discovery of a primary CNS tumor.

Implications:

• This case underscores the potential for misdiagnosis in presumed CNS metastases.
• Rethinking biopsy mandates in specific clinical scenarios may improve patient staging and treatment.
• Accurate diagnosis of primary versus metastatic CNS disease is critical for effective cancer management.