A patient is suspicious of having breast cancer. What type of test will a physician conduct to diagnose the cancer

The correct option is mammography.

To understand why this is the correct diagnostic procedure, let's break down the role of each test mentioned in the options:
1. Mammography: This is a specialized medical imaging technique that uses low-dose X-rays to detect and diagnose changes in breast tissue. A mammogram can reveal abnormal masses, calcium deposits (microcalcifications), or architectural distortions in the breast structure that may indicate cancer, often before a lump can be felt physically. Therefore, it is the primary imaging modality used specifically for screening and diagnosing breast cancer.
2. Blood test: While blood tests (such as complete blood counts or tumor marker tests like CA 15-3) can provide information about a patient's overall health or monitor treatment, they cannot be used on their own to diagnose breast cancer.
3. CT scan: A computed tomography (CT) scan is a detailed cross-sectional imaging test. In breast cancer cases, it is typically used for staging (checking if the cancer has spread to other parts of the body like the lungs, liver, or bones) rather than the initial detection or localized diagnosis of breast tissue.
4. Pap test: A Papanicolaou test (Pap smear) is a screening procedure used to detect precancerous or cancerous cells specifically in the cervix (the opening of the uterus). It has no diagnostic value for breast cancer.

Thus, a physician will conduct a mammography to investigate a suspicion of breast cancer and evaluate the breast tissue for anomalies.