What test definitively diagnoses cancer?

• A. Blood test
• B. MRI
• C. Mammography
• D. Biopsy

Answer: (D)

Definitive cancer diagnosis comes from tissue examined under a microscope. A biopsy collects cells from the suspicious area so a pathologist can assess cellular features, pattern, and invasion to confirm malignancy and determine the cancer type. This histopathologic confirmation is the gold standard for diagnosis.

Blood tests can reveal abnormalities or tumor markers that raise suspicion or monitor disease, but they don’t prove cancer because markers can be false positives or false negatives and are not specific to cancer.

Imaging tests like MRI or mammography reveal where a lesion is and guide further testing, but they cannot definitively distinguish cancer from benign conditions without tissue evidence.

Biopsy can be performed in several ways depending on location—core needle, incisional, excisional, or fine-needle aspiration—yet the essential idea is obtaining a tissue specimen for microscopic analysis to confirm cancer.