Solitary pulmonary nodule as the initial manifestation of isolated metastasis from prostate cancer without bone involvement: A case report

INTRODUCTION: Isolated lung metastases from prostate cancer without any other organ involvement are rare. They are commonly in the form of diffuse or multiple lesions and rarely emerge as a solitary pulmonary nodule. PRESENTATION OF CASE: A 61-year-old man who had undergone a laparoscopic-assisted radical prostatectomy for prostate cancer 16 months prior presented with a growing solitary pulmonary nodule. Positron emission tomography/computed tomography showed an abnormal uptake in the nodule without any other organ involvement. A surgical specimen by a thoracoscopic wedge resection proved a diagnosis of a metastasis from prostate cancer. He is currently alive only with worsening pulmonary metastases at 7 years after the lung surgery. DISCUSSION: A rare entity of isolated pulmonary metastases could be a sole finding of metastatic prostate cancer over the years and its initial manifestation could emerge as a solitary pulmonary nodule. It poses a diagnostic challenge because primary lung cancer is the leading differential diagnosis of solitary pulmonary nodules and is also one of the most frequent second primary malignancies in prostate cancer survivors. CONCLUSION: An aggressive surgical biopsy is essential for definitive histopathological and immunohistochemical analyses of solitary pulmonary nodules to distinguish a rare form of an isolated pulmonary relapse from a second primary lung cancer in prostate cancer survivors.