A case of recurrent massive right sided pleural effusion-an unusual presentation of carcinoma prostate.

Sir,

Carcinoma prostate is the second most common cancer in males worldwide and hematological spread occurs commonly to bones, lung and liver. It has a typical pattern involving axial skeleton and loco regional lymph nodes specially obturator and hypogastric groups. Isolated visceral metastasis in absence of bone metastasis is rare. Pleural involvement is also rare. Pleural effusion as determined on autopsy study ranged from 2.3 to 5%. Herein, we present a case that did not have any urinary symptoms and presented with pleural effusion only.

An 84-year-old gentleman, presented with generalized weakness, dyspnea on exertion and anorexia for 8 months. He was a non-smoker and a known case of Type 2 Diabetes Mellitus taking oral hypoglycemic agents for last 40 years. He had received empirical anti-tuberculosis treatment (ATT) for the above-mentioned symptoms before presenting to us without any improvement. He had no symptoms pertaining to lower urinary tract. He had the Eastern Cooperative Oncology Group (ECOG) performance status 2 and was hemodynamically stable. On physical examination, he had no pallor, no icterus, clubbing or palpable lymphadenopathy. On evaluation, he was found to have dull breath sounds on mid and lower zone of right chest. His chest X-ray posteroanterior (PA) view [Figure 1] showed right-sided pleural effusion. Contrast-enhanced computed tomography (CECT) chest [Figure 2] and abdomen showed massive right pleural effusion with right lung collapse and prostatic enlargement. There were no obvious lung mass or enlarged mediastinal lymph nodes. Sonography of pelvis showed prostatic enlargement with 150 ml post-void residual urine. Pleural fluid examination showed hemorrhagic fluid, glucose 100 mg/dl, proteins 4.5 mg/dl; total cells were 480 with neutrophils 20% and lymphocyte 80%. Pleural fluid adenosine deaminase (ADA) was 32.35 IU/L. No growth of micro-organism was seen on Gram and Zeil Nelson staining to rule out tuberculosis and no growth was seen after 48 hours of urine culture. Pleural fluid cytology revealed fragments from metastatic adenocarcinoma. His serum prostate-specific antigen (PSA) was found to be>148 ng/dl. An ultrasound guided trans rectal prostate biopsy was done, which showed well-differentiated adenocarcinoma of prostate and a Gleason's Score of 6. He underwent surgical hormonal ablation by bilateral high inguinal orchidectomy and he was started on bicalutamide. After 4 weeks of surgery, he improved symptomatically, massive pleural effusion subsided and his serum PSA came down to 13.48 ng/ml. On last follow-up at three months there was no pleural effusion on chest X-ray and his serum PSA was 4.04 ng/ml. Still there was no bony pain or tenderness.

Figure 1

X-Ray chest of patient showing massive right-sided effusion

Figure 2

CECT chest showing massive right-sided pleural effusion

The prognosis of patients with carcinoma prostate is determined by the presence or absence of metastasis. The bones of axial skeleton is the frequent site of metastasic spread, spine metastasis precede lung and liver metastases. Pleural involvement without bone involvement is rare. The main cause of metastatic pleural effusion is adenocarcinoma lung, breast, ovary and stomach. In addition lymphoma, primary mesothelioma and sarcomas may cause effusion. This patient has hemorrhagic pleural effusion and is positive for adenocarcinoma cells. We could not find any carcinoma prostate patient in the literature presenting primarily with pleural effusion showing metastatic adenocarcinoma cells and without any urinary symptoms and bone metastasis. Hence, presence of metastatic pleural effusion in elderly males without any urinary symptoms should warn us to do rectal examination, pelvic sonography and serum PSA levels.

Surgical castration along with hormonal therapy has shown promising results thereby increasing the survival of patients with metastatic adenocarcinoma prostate. Our patient also showed a good response to castration and hormonal therapy and presently after four months there is no pleural effusion and his serum PSA level has dropped markedly up to 4.04 ng/dl. This is a rare occurrence of massive pleural effusion due to local metastasis of carcinoma prostate, emphasizing the need of doing serum PSA and digital rectal examination in patients presenting with malignant pleural effusion.