Pleural Metastasis as an Initial Presentation of Prostate Cancer: Case Report and Literature Review

Our plain-English summary of Pleural Metastasis as an Initial Presentation of Prostate Cancer: Case Report and Literature Review, by K. Skrobisz, K. Miszewski, L. Miszewska, et al (Diagnostics, 2025).

The study

• Authors: K. Skrobisz, K. Miszewski, L. Miszewska, M. Bieńkowski, M. Matuszewski, M. Studniarek
• Journal: Diagnostics
• Published: 2025;15(6)
• Type of article: Case report
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background and Clinical Significance: Prostate cancer (PCa) is among the most commonly diagnosed malignancies in men worldwide. While bone and lymph nodes are the most frequent metastatic sites, prostate cancer cells have the potential to spread to virtually any organ, including the pleura, which is an exceedingly rare initial site of presentation that can mimic mesothelioma or primary lung cancer. Case Presentation: We describe a 77-year-old man who presented with exertional dyspnea and intermittent cough, initially suggesting a cardiopulmonary etiology. Imaging revealed multiple pleural nodules and an extensive right-sided pleural effusion. Despite a borderline serum prostate-specific antigen (PSA) level of 2.91 ng/mL, histopathology and immunohistochemistry of pleural biopsies confirmed metastatic prostate adenocarcinoma. Subsequent imaging identified a PIRADS 5 lesion in the prostate, and a biopsy confirmed ISUP Grade Group 5 disease (Gleason score 4 + 5 = 9). A bone scan showed no skeletal metastases, and a contrast-enhanced CT of the abdomen found no additional metastatic lesions. The patient was started on androgen deprivation therapy followed by abiraterone. This case underscores the diagnostic challenge posed by atypical metastatic presentations of prostate cancer. Low or moderately elevated PSA can obscure suspicion of prostate origin, especially with pleural-based lesions suggestive of mesothelioma. Immunohistochemical markers, including androgen receptors, AMACR, and Prostein, are critical for accurate diagnosis. Conclusions: Clinicians must maintain a high index of suspicion for prostate cancer in older men with unexplained pleural effusions, nodules, or masses, even with low-normal PSA levels. Early recognition and prompt treatment can improve outcomes, despite the rarity and aggressiveness of pleural metastases.

In plain English

This was a case report with a literature review. It described a 77-year-old man with several weeks of breathlessness on exertion and dry cough. Imaging showed a large right-sided pleural effusion (fluid around the lung) and multiple pleural nodules up to 17 mm. About 3800 mL of bloody fluid was drained in two procedures, and testing of the fluid for cancer cells was negative. Pleural biopsies showed metastatic carcinoma with a staining pattern pointing to the prostate. Two markers the authors list as mesothelioma markers, WT1 and D2-40, were negative. His blood PSA was only 2.91 ng/mL, but prostate MRI and biopsy found high-grade cancer (Gleason 4 + 5 = 9). A bone scan and abdominal CT found no other spread. After hormone treatment, imaging at three months showed stable pleural disease and partial relief of breathing symptoms. The authors also summarized six published cases. They concluded that clinicians should remain vigilant for prostate cancer in older men with unexplained pleural effusions. The article does not mention asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case report of a single patient, combined with a literature review that summarized previously published cases
• Who was studied: One 77-year-old man, reported by authors at the Medical University of Gdańsk, Poland; the dates of his care are not stated
• Exposure: No asbestos or occupational exposure is reported. The article notes a 20 pack-year smoking history, with smoking stopped 32 years earlier. The condition described is prostate cancer that had spread to the pleura.
• Main results:
  • In this patient, CT of the chest showed multiple pleural nodules up to 17 mm
  • In this patient, about 3800 mL of bloody pleural fluid was drained in two procedures, and testing of the fluid for cancer cells was negative
  • Pleural biopsies from this patient were positive for androgen receptor, AMACR and focal Prostein, and negative for TTF1, CK20, WT1, D2-40, PAX8, GATA3 and CDX2, which the authors judged consistent with a prostatic origin
  • The patient's serum PSA was 2.91 ng/mL, and prostate biopsy confirmed ISUP grade group 5 disease (Gleason 4 + 5 = 9)
  • In this patient, a bone scan showed no skeletal metastases
  • After hormone treatment, this patient's imaging at three months showed stable pleural disease, and his breathing symptoms were partly relieved
• The authors' conclusion: The authors concluded that clinicians should remain vigilant for metastatic prostate cancer in older men with unexplained pleural effusions, since advanced or high-grade disease may secrete minimal PSA, and that timely pleural biopsy with immunohistochemistry followed by systemic therapy can help stabilize disease and palliate symptoms

Topics

Medical terms in this study, explained in our Lexicon: Metastasis, Pleura, Mesothelioma, Lung Cancer, Dyspnea, Etiology, Pleural Effusion, Histopathology.

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