Atlantoaxial subluxation and nasopharyngeal necrosis complicating suspected granulomatosis with polyangiitis.

Granulomatosis polyangiitis (GPA, formerly Wegener granulomatosis) is a vasculitis that typically involves the upper respiratory tract, lungs, and kidneys. The 2 established methods to confirm a suspicion of GPA are the antineutrophil cytoplasmic antibody (ANCA) test and biopsy. However, ANCA-negative cases have been known to occur, and it can be difficult to find biopsy evidence of granulomatous disease.We report a case of suspected granulomatosis with polyangiitis limited to the nasopharynx. With a negative ANCA and no histological evidence, our diagnosis was founded on the exclusion of other diagnoses and the response to cyclophosphamide therapy. This case is unique because the patient's lesion resulted in atlantoaxial instability, which required a posterior spinal fusion at C1-C2. This is the first reported case of suspected GPA producing damage to the cervical spine and threatening the spinal cord.