Prostate Adenocarcinoma with Negative Immunohistochemical Stain of Prostate-specific Antigen Presenting with Cervical Mass: A Case Report

Cervical regional nodal involvement, as the first manifestation of prostatic cancer, has been rarely reported. Prostate cancer metastasis to the supraclavicular lymph nodes with negative immunohistochemical stain of PSA is even rarer. We report a case of prostate cancer with negative immunohistochemical stain of prostate-specific antigen presenting with left supraclavicular node enlargement. A 63-year-old man was referred to our hospital for a left supraclavicular mass. He had a family history of gastric cancer (two brothers had died of gastric cancer). Enhanced computed tomography of the abdomen revealed retroperitoneal lymph node enlargement. Gastroscopy revealed no evidence of any gastric tumor. Biopsy of the left-sided supraclavicular lymph nodes revealed metastatic adenocarcinoma with a negative prostate-specific antigen (PSA) stain. The serum tumor markers were examined, revealing PSA levels of 21.820 ng/ml. Biopsy of the prostate disclosed poorly-to-moderately differentiated adenocarcinoma (Gleason 4 + 4 = 8). Although rare, prostate cancer should be considered in the differential diagnoses of elderly men with undetermined original adenocarcinoma, metastatic to the supraclavicular lymph nodes. Rectal examination, serum PSA and pelvic image can be helpful to lead the diagnosis. PSA stain may be weak or negative in some poorly differentiated patients, however, it is still a sensitive and specific marker of prostatic differentiation and must be routinely applied.