Background
Metastatic prostate cancer typically manifests with metastases to the lungs, bones, and adrenal glands. Here, we report a unique case where the initial presentation involved pleural nodules, subsequently leading to the discovery of pleural and pericardial metastases.
Case Presentation
Our patient, a 73-year-old male with a history of active tobacco use disorder, COPD, and right shoulder melanoma (2004), initially presented to his primary care physician for a routine visit. Following a Low Dose Chest CT scan (LDCT), numerous new pleural nodules were identified. Physical examination revealed small nevi and skin tags, but no malignant characteristics. Initial concerns centered on the potential recurrence of malignant melanoma with pleural metastases or an inflammatory condition. Subsequent PET scan results raised significant suspicion of malignancy. PSA was 2.41. Pleuroscopy biopsies revealed invasive nonsmall cell carcinoma, positive for NKX31 and MOC31, but negative for S100, PSA, and synaptophysin. This pattern strongly suggests metastatic prostate cancer despite the absence of PSA staining. (Stage IV B: cTxcN1cM1c). A subsequent PSMA PET highlighted extensive metastatic involvement in the pericardium, posterior and mediastinal pleura, mediastinum, and ribs. Treatment commenced with Degarelix followed by the standard regimen of Docetaxel, Abiraterone, and prednisone. Genetic counseling and palliative care services were additionally recommended.
Discussion
Prostate cancer typically spreads to bones, lungs, liver, and adrenal glands. Rarely, it appears in sites like pericardium and pleura. Pleural metastases are usually found postmortem; clinical diagnosis is rare. Pericardial metastases are exceptionally uncommon, with few documented cases. The precise mechanism of metastatic dissemination remains uncertain, with theories suggesting spread through the vertebral-venous plexus or via the vena cava to distant organs. Treatment approaches vary based on symptomatic effusions, ranging from pericardiocentesis, thoracocentesis to chemotherapy, radiotherapy, and hormone therapy. Studies have shown systemic docetaxel to be effective in managing pleural and pericardial symptoms. Despite their rarity, healthcare providers should consider these possibilities when encountering pleural thickening or pericardial abnormalities on imaging studies.
Conclusions
Pleural and pericardial metastases represent uncommon occurrences in prostate cancer. Continued research efforts can facilitate early detection of metastatic disease, enabling more effective and precisely targeted management strategies when symptoms manifest.