A 58 YEAR OLD MALE PATIENT WAS admitted with a two month history of short ness of breath and left hypochondral pain. The plain radiograph of the chest showed large left pleural effusion. Computed tomography (CT) of the chest confirmed the presence of a large left pleural effusion. In addition, it showed circumferential nodular masses involving the left parietal pleura. The gallium scan showed diffuse circumferential uptake in the left thoracic cavity. Fused CT/Ga-67 SPECT image, using Syngo fusion software (Siemens Medical Solutions), allowed the precise localization of the gallium uptake to the left pleura. The patient underwent pleural biopsy, which showed a diffuse large B cell ymphoma. Most of the tumours involving the pleura invade the pleura secondarily. The usual primary tumours are bronchogenic carcinoma, breast cancer, lymphoma, and ovarian or gastric tumours. Primary benign and malignant tumours of the pleura are uncommon. Primary malignant pleural neoplasms can present as solitary nodular mass or diffuse infiltrating tumour.