Osteoid Osteoma-Ulna

15 years old girl comes with pain along the extensor carpi ulnaris tendon ( ECU) with clinical diagnosis of extensor carpi ulnaris groove syndrome.

Case Submitted By-

1. DR.M.G.K.MURTHY, SR.CONSULTANT RADIOLOGIST
2. MR.ABDUL HAMID

Teaching Points

- ECU arises by two tendons one from lateral epicondyle and the other the mid 1/3rd of the posterior ulna and its inserts into the posterior base of the 5th metacarpal. ECU passes the groove on the medial side of the distal ulna and its covered by the annular ligament.

 

- CT shows small well defined, regular, subperiosteal, septated mixed density lesion with a hyperdense speck as the nidus with no soft tissue abnormality or joint abnormality with no significant periosteal response suggesting osteoid osteoma.

- Osteoid osteoma, and tenosynovitis along the ECU are difficult to differentiate on clinical grounds.