Presentation
Progressing thenar pain and weakness of the thumb.
Patient Data
There is subtle permeative lytic destruction of the first metacarpal, with questionable areas of cortical destruction throughout the diaphysis. On the lateral view, subtle periosteal elevation is appreciated along the dorsomedial aspect of the proxmial metaphysis of the first metacarpal.
There are also mild degerative changes at the second, third, and fourth distal interphalangeal joint, scaphotrapezial joint and 1st metacarpophalangeal with joint space narrowing and osteophytosis.
A 2.2 x 1.3 x 2.6 cm enhancing soft tissue mass is observed along the dorsolateral aspect of the right first metacarpal, consistent with residual or recurrent tumor, as the patient reports history of osteosarcoma status post chemotherapy.
The mass envelops the extensor pollicis longus and extensor pollicis brevis tendons, without definite invasion of the underlying metacarpal; however, an abnormal low T1 high STIR signal is seen within the 1st metacarpal diaphysis, which likely represnts osteosarcoma with in the bone, but also has a double line appearance suggestive of bone infarction. If infarction, it is likely secondary to prior radiation therapy in the region.
Status post amputation of 1st and 2nd ray, including trapezium and trapezoid. No interval complicaton or evidence of recurrence is seen.
Case Discussion
Although the findings related to osteosarcoma in the inital film are subtle, they are present and warrant further investigation, especially given that the degnerative changes don't fit the clinical complaint.