Pleural Infection as the Clinical Presentation of Lung Cancer: A Case Report.

We present a case of a 61-year-old female who was admitted with a four-week history of productive cough, worsening exertional dyspnea, and severe pleuritic chest pain, alongside several months of facial and neck swelling. Initial investigations revealed a right-sided encysted pleural effusion with biochemical features consistent with empyema, prompting intercostal drain insertion and intravenous antibiotics. A persistent cervical fullness prompted a bedside neck ultrasound, which demonstrated abnormal lymphadenopathy. A subsequent CT thorax revealed a right lung mass with mediastinal lymphadenopathy, bilateral adrenal metastases, and significant narrowing of the superior vena cava. Histological analysis of the supraclavicular lymph node confirmed metastatic small-cell lung carcinoma (SCLC). The patient was treated with corticosteroids and urgent thoracic radiotherapy for superior vena cava obstruction, followed by systemic palliative chemotherapy.  This case highlights a very unusual presentation of advanced SCLC masquerading as empyema and illustrates the importance of maintaining a broad differential diagnosis in patients with pleural infections, particularly when atypical features are present.