Probable Pleural-Based Pulmonary Tuberculoma Mimicking Lung Malignancy: A Case Report.

Pleural-based lung masses can mimic lung cancer and differentiating malignancy from other causes remains a diagnostic challenge. We report a case of a 50-year-old man who presented with an acute onset pleuritic chest pain and a history of weight loss. Chest radiography and computed tomography scan showed a solitary pleural-based lung lesion that was suspicious for malignancy. Two sessions of computed tomography guided biopsies yielded only necrotic tissue. An endobronchial ultrasound-guided transbronchial needle aspiration showed inflammatory cells but was non-diagnostic. Video-assisted thoracoscopic surgery wedge resection of the lesion provided tissue revealing a chronic granulomatous mass which showed caseous necrosis and Langhans type giant cells on histopathology. A probable diagnosis of tuberculoma was made based on these findings when other investigations did not reveal a definitive diagnosis and the patient was treated with antitubercular medicines. This case report highlights the challenges encountered in diagnosing a pleural-based solitary lung mass. The key lesson learnt is that tuberculosis should remain in the differential diagnosis of pleural-based lung mass in endemic settings, especially when repeated biopsies show necrosis without malignant cells.