Seventy-nine cases with known carcinoma of the lung or breast who underwent both bone marrow aspiration and Tc-99m MDP bone scintigraphy were reviewed. The bone images were assessed for the presence of the pattern of bone marrow expansion which is visualized by diffuse increased metaphyseal activity, particularly evident at the knees, ankles, and elbows. This pattern was found to be an insensitive marker for the presence of marrow metastases (sensitivity 15%). The specificity of the finding was 86%. When diffuse increased metaphyseal activity is present on a Tc-99m MDP bone span in a patient with malignant disease, the possibility of bone marrow metastases should be pursued by marrow aspiration and biopsy.
From the Division of Nuclear Medicine, Department of Radiology, Ottawa Civic Hospital, Ottawa, Canada