Diffuse Pleural Mesothelioma: A Challenge in Early Diagnosis.

We present the clinical case of a 58-year-old female patient, a smoker with occupational exposure to respiratory toxins, who was admitted to our clinic following evaluation in an emergency department, where she was diagnosed with a moderate right pleural effusion. Upon admission, the patient exhibited respiratory symptoms, including progressive dyspnea with a moderate exertion threshold, right posterior pleuritic chest pain radiating anteriorly, occasional episodes of low-grade fever, and persistent febrile symptoms lasting approximately two weeks. In this clinical context, the diagnostic process was guided by the presence of right pleural effusion syndrome, which was refractory to conservative medical therapy. This necessitated a careful and stepwise expansion of investigations, ultimately leading to the diagnosis of malignant pleural mesothelioma. This case underscores the diagnostic challenges posed by pleural effusion, the necessity of adhering to the diagnostic algorithm, and the critical role of the multidisciplinary team. The diagnostic approach, often complex and challenging, necessitates a multidimensional strategy that integrates the correlation and synthesis of data obtained through anamnesis, alongside advanced diagnostic procedures such as pleural biopsy, which remains the gold standard. This comprehensive process is essential for formulating a diagnostic suspicion, with the final diagnosis intended to be one of exclusion.