A 62-year-old heavy smoker with a lung mass on chest radiograph develops headaches and a focal seizure. MRI shows three well-demarcated ring-enhancing lesions at the grey-white junction with disproportionate perilesional oedema and no dural attachment. What is the most likely origin of these lesions?
- A Renal cell carcinoma
- B Lung carcinoma ✓
- C Prostate carcinoma
- D Colorectal carcinoma
Correct answer: B. Lung carcinoma
Explanation
Metastases are the most common intracranial tumours in adults, favouring the grey-white junction where narrow vessels arrest emboli. In men, lung carcinoma is the leading primary source of brain metastasis; in women it is breast cancer. Renal cell carcinoma metastasises to brain frequently but is far less common than lung overall. Prostate carcinoma spreads predominantly to bone and rarely to brain parenchyma. Multiple lesions with marked vasogenic oedema in a smoker point firmly to lung primary.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.