Which of the following is not a common diagnostic test for lung malignancy?

The choice of CA-125 as the correct answer is based on its general use in medical diagnostics rather than specifically for lung malignancy. CA-125 is a tumor marker primarily associated with ovarian cancer and is often utilized to monitor treatment response or disease recurrence in ovarian cancer patients. While it may have some utility in other contexts, it is not a standard diagnostic test for lung cancer.

In contrast, chest X-rays, CT scans, and bronchoscopy are all commonly employed diagnostic procedures for assessing lung malignancies. A chest X-ray can reveal abnormal masses in the lungs that may suggest cancer, while a CT scan provides a more detailed, cross-sectional view of the lungs and surrounding structures, allowing for more precise diagnosis and staging of lung cancer. Bronchoscopy allows direct visualization of the airways and lung tissue, enabling biopsy of suspicious lesions for histopathological examination.

Thus, the context of lung cancer diagnostics clearly supports the assertion that CA-125 is not a standard test for lung malignancy, highlighting its specificity to other cancers, particularly ovarian carcinoma.