Isolated Solitary Lung Nodule in a Patient With Idiopathic Pulmonary Fibrosis and Concomitant Prostate Cancer: A Challenging Diagnosis

Prostate cancer is the most commonly diagnosed malignancy and the second most common cause of death in men after lung cancer. Isolated pulmonary metastasis from prostate cancer, without bone or lymph node involvement, is rare and accounts for less than 1% of cases. The diagnosis of solitary lung metastasis is even more challenging in patients with concomitant pulmonary disease and often mandates tissue biopsy from the lung nodule. We herein present a case of an elderly man with idiopathic pulmonary fibrosis who presented with a solitary lung nodule three years after a laparoscopic radical prostatectomy for localized prostate cancer. Initially thought as a primary lung lesion secondary to his pulmonary fibrosis, further workup and ultimately a lung segmentectomy proved a metastatic prostatic adenocarcinoma. The serum prostatic specific antigen dropped to nadir following resection, and he remained stable six months later.