Isolated Pulmonary Metastasis Presenting with an CEA Elevation Five Years After Radical Prostatectomy

A 60-year-old man with prostate cancer (PC) was admitted to our hospital in October 2009 for follow up visit. He underwent radical prostatectomy for PC five years ago. The patient's physical examination and complete blood count, biochemical investigations, and chest x-ray were within normal limits. The patient's carcinoembryonic antigen (CEA) and prostate-specific antigen (PSA) levels were 529 ng/mL (normal, <3 ng/mL) and 7.5 ng/mL (normal, <4 ng/mL) respectively. Cranial, thoracic, and abdominal computerized tomography (CT) and whole body bone scan were done. The patient's chest CT scan revealed irregular, 18 mm nodule of the right lower lobe of lung. The cranial and abdominal CT and whole body bone scan revealed no abnormality. The endoscopic evaluation of upper and lower gastrointestinal system was normal. Since there was no evidence of metastatic site other than lung in workup, the patient underwent wedge resection of the lung lesion at December 2009 and histopathologic examination revealed the diagnosis of malignant epithelial tumor. The immunohistochemical examination showed strong staining of tumor cells with PSA, PAP and CEA but CK7, CK20, TTF-1 and SPA were negative (Figure 1). So the isolated lung metastasis of prostate adenocarcinoma was considered and bicalutamide and leuprolide acetate were started. One month later PSA and CEA level were 1.14 and 473 ng / ml, respectively, and treatment was continued with leuprolide. In March 2012, he was admitted for follow up visit. The patient's CEA and PSA levels were 639 ng/mL and 1.86 ng/mL respectively.