Prostate adenocarcinoma with negative immunohistochemical stain of prostate-specific antigen presenting with cervical mass: A case report
A 63-year-old male was referred to our hospital for a left supraclavicular mass. The patient complained of an asymptomatic swelling on the left side of his neck for approximately one month. He denied any other subjective complaints, including difficulty in swallowing or breathing. However, he had a family history of gastric cancer (two brothers died of gastric cancer). Physical examination of the patient's neck revealed a hard left-sided neck mass, approximately 4 cm in diameter. Subsequent computerized tomography (CT) scan of the head and neck showed a 5 cm, solid, left supraclavicular mass, with extension from the clavicles to the true vocal cords []. The abdominal CT scan showed multiple enlarged retroperitoneal lymph nodes []. Percutaneous fine needle aspiration (FNA) was performed and interpreted as poorly differentiated adenocarcinoma.\nLaryngoscopy, bronchoscopy, colonoscopy, and gastroscopy were performed on the patient, and no evidence of any tumor was found. Biopsy of the left supraclavicular mass showed metastatic adenocarcinoma and the immunohistochemistry tests showed up with a negative PSA stain [] and positive P504s stain []. A digital rectal examination revealed an enlarged prostate with an uneven surface. In the absence of other signs or symptoms, serum tumor markers were measured and the PSA level was found to be increased to 21.820 ng/mL. Although the PSA stain was negative, metastatic adenocarcinoma from the prostate was greatly suspected, considering the morphology, P504s stain, and PSA level. The patient underwent a transrectal ultrasound-guided biopsy and the histopathological diagnosis was poorly differentiated invasive acinar adenocarcinoma (Gleason score 8 = 4 + 4; cT2aNxM1) with a negative PSA stain [] and positive P504s stain []. Finally, a whole-body bone scan was performed with a normal result.\nThe patient started treatment for the neoplasm with an androgen blockade (oral flutamide and a GnRH agonist) in August 2011. Eight months later, the serum PSA level declined to 1.360 ng/ml and a cervical ultrasound examination showed a significant response in terms of the number and size of the nodal involvement.