Pulmonary lymphangitic carcinomatosis with ground‐glass opacities as presentation of prostate cancer

There is a broad differential diagnosis for interstitial shadows on chest computed tomography in rheumatoid arthritis patients, especially those previously treated with immunosuppressant drugs. We report an immunocompromised rheumatoid arthritis patient in respiratory failure with diffuse ground‐glass opacities (GGOs), who was diagnosed with pulmonary lymphangitic carcinomatosis as the initial presentation of prostate cancer. He was successfully treated with chemohormonal androgen deprivation therapy, including bicalutamide, leuprorelin acetate, denosumab, and docetaxel. Metastatic pulmonary lymphangitis, rarely from the prostate, should always be considered in the differential diagnosis of GGOs, even when the patient has no known prior malignancies.