59-year-old female with first metacarpal changes and old MRI. Presents with pain at the basilar joint. Note is made of a focus of increased signal abnormality on fluid sensitive sequences within the first metacarpal with internal low signal intensity septations. There is thin peripheral enhancement on postcontrast sequences distally with more confluent enhancement proximally within the aforementioned lesion. There are subchondral cysts within the trapezium and scaphoid. The remainder of the bone marrow signal is within normal limits. There is fluid within the basilar joint. There is a tiny ossicle along the base of the first metacarpal which may represent a loose body within the basilar joint. Moderate osteoarthritis affects the basilar joint. Mild osteoarthritis affects the interphalangeal joint of the thumb. The imaged musculature is normal in appearance. The flexor and extensor tendons appear intact.
1. Enhancing lesion within the first metacarpal. Differential considerations include fibrous dysplasia, giant cell reparative granuloma, giant cell tumor, and less likely an enchondroma. 2. Osteoarthritis of the basilar joint with a mild synovitis.