2021 Volume 70 Issue 2 Pages 362-367
Prostatic adenocarcinoma (PA) cells are rarely detected in urine and pleural effusion cytology specimens. Because of the difficulty in cytological identification of PA cells in cytological specimens, immunohistochemical staining of cell block (CB) preparations is useful for the cytological diagnosis of PA. We report a case of PA diagnosed in the urine and pleural effusion cytology specimens. A 70-year-old man visited our hospital for further assessment of an elevated serum prostatic specific antigen (PSA) level pointed out during a health checkup. Core needle biopsy specimens of the prostate showed adenocarcinoma with obvious nucleoli that formed crowded small glands or fused glands lacking a layer of basal cells. Since metastasis of the prostatic cancer to pelvic lymph nodes and direct invasion into the seminal vesicle were suspected on the basis of magnetic resonance imaging findings, prostatectomy was not performed and hormone therapy was started. Seven years after the initial diagnosis of PA, microscopic hematuria was observed in a laboratory test. Urinary cytology specimens showed adenocarcinoma cells having eccentrically located nuclei with obvious nucleoli either in scattering cells or in cell clusters. The adenocarcinoma cells were immunohistochemically positive for PSA in CB specimens. These findings were consistent with PA. After nine months, computed tomography revealed bilateral pleural effusion. In the pleural effusion cytology, adenocarcinoma cells having the atypical nuclei containing obvious nucleoli formed ball-like clusters. CB specimens of pleural effusion showed adenocarcinoma cells positive for PSA, confirming the diagnosis of pleural metastasis of the PA. The PSA immunohistochemical staining in CB preparations is useful for the confirmation of PA diagnosis based on urinary and pleural effusion cytological findings.
