Presentation
Cough and chronic right hip pain
Patient Data
There is a poorly defined erosion at the lateral aspect of the right femoral head/neck junction, with poorly visualized cortical margins along the axial aspect of the femoral head and acetabulum. Mild juxtarticular osteopenia is also noted on the right. The gluteal, capsular and psoas fat pads are markedly distorted on the right, indicating a large joint effusion.
There is a mass in the right upper lobe containing a small area of calcification. There is also a 1 cm linear density seen in the right middle lobe. Nipple shadows are noted.
The mass in the right upper lobe is revealed to be a large tuberculoma. An 8 mm lymph node is also identified in the subcarinal space.
Following treatment there is ankylosis of the femoroacetabular joint with intramedullary nail screw sabilization of the proximal femur.
Case Discussion
This case shows the classic features of tuberculous arthritis, demonstrating Phemister triad with a marginal erosion at the lateral femoral head neck junction, juxta-articular osteopenia and late loss of joint space. Identifying the erosion at the femoral head neck junction in isolation could be misleading, as an apple core deformity is most often seen with synovial osteochondromatosis, but may also be seen with PVNS. Rarely, amyloidosis or rheumatoid arthritis may also lead to an "apple core" erosion pattern.
A quote I like to keep in mind when reading chest radiographs: "There is no radiographic appearance [on chest radiographs] that is inconsistent with the diagnosis of tuberculosis infection."
This case is courtesy of Deborah M. Forrester, MD