Pleural effusion as presentation of metastatic adenocarcinoma of prostate.

To the Editor: Prostate carcinoma is one of the most common malignancies in men, (1) and spreads most frequently to bone, lung, and liver. (2) Pleural involvement is rare. Pleural effusion as determined by autopsy ranged from 2.3 to 5%. (3,4)

We describe two elderly male patients with adenocarcinoma of the prostate and secondary pleural effusion. Our first patient, a 72-year-old man, received 40 pelvic radiotherapy sessions and began treatment with bicalutamide and triptorelin. He presented with dyspnea and oppressive pain on the right side of the chest. No cough, fever or other respiratory symptoms were present. He had no symptoms of heart failure. Physical examination revealed reduced breath sounds in the right lung. Blood analysis showed elevation of prostatic specific antigen (205.12 ng/mL). Chest radiography revealed right pleural effusion. Thoracocentesis produced bloody pleural liquid with elevated proteins, lactate dehydrogenase (LDH) and an elevated prostate-specific antigen (PSA) of 429.77 ng/mL but no malignant cells. Pleural biopsy revealed malignant cells, acid phosphatase positive. The final diagnosis was pleural metastases with secondary effusion due to prostate adenocarcinoma.

Our second patient was a 77-year-old man treated with triptorelin. He had anorexia, severe dyspnea, productive cough, and right pleural pain. Physical examination revealed decreased breath sounds on the lower right side of the thorax. He had an elevated PSA (257 ng/mL). Chest radiography revealed right pleural effusion and diagnostic thoraco-centesis produced bloody liquid with elevated proteins, LDH and a PSA of 509.48 ng/mL but no malignant cells. Osteoblastic metastases in the vertebrae were confirmed by CT scan. The final diagnosis was pleural effusion secondary to metastatic prostate adenocarcinoma.

The diagnostic method used to determine the metastatic origin of pleural effusion remains controversial. In our patients, cytology of pleural liquid was negative, but the PSA levels in the pleural effusion fluid were elevated, and metastases were subsequently confirmed histologically and radiologically. This suggests that an elevated PSA level in the pleural effusion may be used to diagnose metastatic adenocarcinoma of the prostate, as noted by Cascinu et al. (5) More studies are needed to determine not only the prevalence of metastatic pleural effusions in patients with adenocarcinoma of the prostate but an optimal diagnostic strategy as well.

Pablo Garcia de Paso Mora 

Juan Jose Rios Blanco, PHD

Francisco Jose Pascual Pareja

Carolina Castillo Torres

Alvaro Pinto Marin

Africa Sendino Revuelta, PHD

Juan Jose Vazquez Rodriguez

Departments of Internal Medicine Service,

Pathology, and Oncology

University Hospital la Paz

Madrid, Spain

References

1. American Cancer Society. Cancer Facts and Figures 2003. Availablein: http://www.cancer.org/downloads/STT/CAFF2003PWSecured.pdf. Accessed

2. Carrol PC, Lee KL, Fuks ZY. Cancer of the prostate. In: DeVita VT, Hellman S, eds. Cancer: Principles and Practice of Oncology. Philadelphia, Lippincott Williams and Wilkins, 6th ed, 2001, pp. 1418-1479.

3. Renshaw AA, Nappi D, Cibas ES. Cytology of metastatic adenocarcinoma of the prostate in pleural effusions. Diagnostic Cytopathology. 1996;15:103-107.

4. Rapaport Ah, Omenn GS. Dermatomyositis and malignant effusions: rare manifestations of carcinoma of the prostate. Journal of Urology 1968;100:183-187.

5. Cascinu S, Del Ferro, E, Barbani I, et al. Tumor markers in the diagnosis of malignant serous effusions. American Journal of Clinical Oncology 1997;20:247-250.

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