Musculoskeletal manifestations of sarcoidosis are relatively rare, when compared to the common pulmonary form of the disease, and estimated to occur in only 5-10% cases ². Isolated extrapulmonary sarcoidosis is rare, found to be only 2% of all sarcoidosis cases in an epidemiological study in the US of 736 patients with known sarcoidosis ³.

Musculoskeletal symptoms, e.g. arthralgia, are more common than actual visible radiographic pathology.

The appearances of the hands and feet in this case is classic:

• acro-osteolysis
• cyst-like lesions of the phalanges
  • hands more commonly affected than the feet
• lace-like osteopenia

This patient's bony changes of sarcoid did not extend to the vertebrae or other structures of the axial skeleton.

When the appearances are typical, as here, the radiological diagnosis is usually fairly clear-cut. However when only one or two cyst-like lesions are present, it can be difficult to rule out differentials, such as metastases.