Absence of the clavicle and destruction of the acromion process, scapular spine and part of the scapular body without an associated destructive soft-tissue mass are findings consistent with Gorham massive osteolysis or "vanishing bone disease." The STIR hyperintense signal adjacent to the remaining superior border of the scapula most likely represents hyperemia and lymphangiomatosis/hemangiomatosis associated with Gorham disease. 

Gorham disease is exceptionally rare, and the differential diagnosis for lytic destruction involving multiple adjacent osseous structures and no associated soft tissue mass includes previous infectious destruction or previous surgical resection. The differential diagnosis for the radiographic findings by themselves without cross-sectional imaging could include: osteomyelitis, aneurysmal bone cyst, lytic metastasis, purely lytic osteosarcoma, Ewing sarcoma, lymphoma, Paget disease, as well as other less likely causes. 

This case is courtesy of Eric White, MD, who generously shared it with me.