Paget disease of the humerus mimicking metastatic disease in a patient with metastatic malignant mesothelioma on whole body F-18 FDG PET/CT
Friday, June 27th, 2008.
Clinical Nuclear Medicine. 33(7):510-512, July 2008. [Link]
Mahmood S, Martinez de Llano SR.
Department of Radiology, Nuclear Medicine Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA. smahmood@yahoo.com
Abstract
A 71-year-old man with newly diagnosed malignant mesothelioma was referred for an F-18 FDG PET/CT study to evaluate the extent of disease. PET showed mild FDG uptake in the right chest, corresponding to a lobulated, mass-like right pleural effusion versus thickening involving the entire right pleural space, and some mediastinal involvement, on the accompanying CT scan. In addition, marked FDG uptake was seen in the proximal left humerus, suspicious for an osseous metastasis. The corresponding CT scan findings of cortical thickening and a "Swiss cheese" appearance were most consistent with Paget disease. The intense FDG uptake in an osseous lesion on FDG-PET in our case reminds us of the variable nature of FDG uptake in Paget disease, the possibility of false-positive findings on FDG-PET in patients with cancer, and the usefulness of the fusion techniques in the evaluation of skeletal lesions, with the potential for discriminating between benign Paget disease and other pathologic bone findings.
Glossary
- scan
- a study using either x-rays or radioactive isotopes to produce images of internal body organs.
- metastasis
- (meh-tas-teh-sis) the spread of cancer cells to distant areas of the body by way of the lymph system or bloodstream.
- lesion
- (lee-zhun) a change in body tissue; sometimes used as another word for tumor.
- cancer
- malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.
- CT scan
- computed tomography (tom-og-ruh-fee), an imaging test in which many x-rays are taken of a part of the body to produce cross-sectional pictures of internal organs. Except for the injection of a dye (needed in some but not all cases), this is a painless procedure that can be done in an outpatient clinic. It is often referred to as a "CT" or "CAT" scan.
- benign
- (be-nine) not cancer; not malignant.
- mesothelioma
- a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.
- pleural effusion
- an abnormal accumulation of fluid, usually caused by trauma or disease, in the pleural space.
