Malignant pleural effusion and Tc-99m MDP accumulation

Two case reports of malignant pleural effusion from breast carcinoma, with scans showing a striking accumulation of Tc-99m MDP, are presented. The Tc-99m MDP was in the pleural fluid and not in the pleura as demonstrated by shift with gravity. Possible mechanisms of malignant effusion accumulation of Tc-99m MDP are suggested. The scant literature on the subject is reviewed.