Abstract
BACKGROUND: Malignant pleural mesothelioma (MPM), a rare aggressive malignancy, is primarily caused by asbestos exposure. MPM typically affects older adults (median age, 76 years), is uncommon in those under age 50 years and shows male predominance. Based on the American Society of Clinical Oncology guidelines, F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) is essential for initial MPM staging. Integrating quantitative FDG metabolic data with computed tomography (CT) anatomy optimizes biopsy accuracy and staging. CASE SUMMARY: A 21-year-old female college student presented with fever (peak 38.4 °C), cough, and white mucoid sputum after cold exposure. Initial evaluation revealed elevated C-reactive protein [C-reactive protein (CRP); 65.52 mg/L] and Mycoplasma pneumoniae IgM. Despite resolution of fever following a 14-day moxifloxacin regimen, persistent cough prompted chest CT, which demonstrated left pleural mass-like thickenings. Levofloxacin therapy for 2 weeks failed to alleviate symptoms, accompanied by 2.5-kg weight loss over 1 month. Re-evaluation showed rising CRP (88.87 mg/L) with stable CT lesions, and negative T-cell spot test for tuberculosis and tumor markers. Contrast-enhanced CT revealed heterogeneously enhancing masses, while PET/CT detected two broad-based pleural lesions with intense FDG avidity. CT-guided biopsy confirmed epithelioid MPM. Thoracoscopy exposed diffuse fragile, hemorrhagic nodules implanting on diaphragmatic and parietal pleura, confirming metastatic MPM with partial resection performed. This presentation challenges conventional imaging paradigms of MPM, underscoring its diagnostic complexity. CONCLUSION: MPM should still be considered an important differential diagnosis in young patients presenting with solitary pleural masses and no history of typical asbestos exposure. F-18 FDG PET/CT, while serving as an essential component of initial staging for MPM, has some inherent limitations.