Malignant pleural mesothelioma.

Malignant pleural mesothelioma is a rare and aggressive tumour of the pleura, commonly linked to asbestos exposure. However, its diagnosis is challenging, especially without known exposure. We present the case of a woman in her early 70s with no history of asbestos exposure, who presented with progressive breathlessness and left-sided chest pain. Radiological assessment revealed a large pleural effusion and nodular pleural thickening. Malignant pleural mesothelioma was confirmed through histopathological analysis of biopsies obtained via medical thoracoscopy. The patient was initiated on a palliative chemotherapy regimen, underwent talc slurry pleurodesis for recurrent effusion, and is currently under follow-up. This case emphasises the importance of a high index of suspicion for malignant pleural mesothelioma in patients with unexplained pleural effusion, even in the absence of typical risk factors, and the need for a timely diagnosis due to the disease's dismal prognosis.