Introduction: Prostate cancer has a high tendency to spread to bone. Pulmonary metastasis and generalized lymphadenopathy commonly develop after pelvic and bone involvement have already occurred. Few patients with prostate cancer present initially with symptomatic metastatic lung lesions and lymphadenopathy without any other concomitant distant dissemination.
Case presentation: We report a case of a 73-year-old white male who sought medical help for symptoms of cough, hemoptysis, and dyspnea. A chest X-ray was done revealing multiple "cannon ball" infiltrates involving all segments of the lung parenchyma. Fine-needle aspiration cytology under computed tomography guidance of a subpleural lesion revealed adenocarcinomatous cells. Despite the absence of any detectable osseous lesions and with the presence of multiple hilar, mediastinal, para-aortic, and pelvic lymphadenopathy, the patient had a complete work-up in search for the primary adenocarcinoma. His prostate specific antigen was 146 ng/ml and a prostatic biopsy done, revealing an acinar prostatic adenocarcinoma. A tru-cut biopsy of a lung lesion under computed tomography guidance showed a metastatic prostatic adenocarcinoma positive for prostate specific antigen stain.
Conclusion: This case sheds light on an unusual metastatic pattern of prostatic adenocarcinoma. It also emphasizes the importance of including prostate cancer in the differential diagnosis of men with adenocarcinoma of unknown origin.