Microscopic pulmonary tumor embolism from adenocarcinoma of the prostate

INTRODUCTION: Microscopic pulmonary tumor embolisms from prostate cancer are extremely rare. In this case of prostate cancer, microscopic pulmonary tumor embolism developed during androgen deprivation therapy. CASE PRESENTATION: A 56‐year‐old man was diagnosed with prostate cancer and underwent androgen deprivation therapy. Three months after starting treatment, he noticed shortness of breath and developed acute progressive dyspnea. He was diagnosed with pulmonary hypertension; however, the cause was not found. His dyspnea was progressive and he died 40 days after the onset of symptoms. Autopsy proved that the cause of pulmonary hypertension was microscopic pulmonary tumor emboli from prostate cancer. Furthermore, histology revealed differences in the androgen receptors in the prostate and emboli, with significantly greater Ki‐67 expression in the emboli than in the prostate. CONCLUSION: Prostate cancer proliferated in the pulmonary artery after hematogenous metastasis, caused vascular occlusion, and formed microscopic pulmonary tumor embolisms.