Dr. Mayo presented a great case of an atypical presentation of GPA in an elderly female with a history of breast cancer who presented with progressive, non-productive cough and nasal congestion despite abx courses, found to have a single cavitary lung lesion that ultimately showed granulomas in addition to +PR3-ANCA.
We reviewed the ddx of cavitary lung lesions, especially given our patient had an extensive travel history and personal history of breast cancer. The differential includes:
- Infections (necrotizing infections with anaerobic or other bacteria, mycobacteria, fungi, parasites or septic pulmonary emboli)
- Non-infectious (PE with infarction, vasculitis, neoplasm, COP, sarcoid, rheumatoid nodules, among others)
Dr. Mayo presented information regarding the ACR guidelines for diagnosis of GPA (included below).
She additionally reviewed a 2005 RCT by de Groot et al published in Arthritis & Rheumatology comparing cyclophosphamide and methotrexate for induction and remission of ANCA-associated vasculitis without significant renal involvement. This study found that remission with methotrexate took about 2 months longer compared to cyclophosphamide. Additionally, methotrexate had higher relapse rates as well. However, it is still important to consider the potential risk/benefit profile of MTX vs CYC for each individual patient.