Atypical manifestations of granulomatosis with polyangiitis: the diagnostic challenge for pulmonologists

This is a review considering atypical manifestations of granulomatosis with polyangiitis (GPA). Virtually any organ can be affected, and in some patients, GPA can manifest unusually. Since thoracic involvement of GPA often predominates, the first who might be expected to establish a diagnosis are pulmonary specialists. We would like to familiarize pulmonary specialists with several extra-ELK (E: ear-nose-throat; L: lung; K: kidney) involvements of the disease. We describe sites rarely affected by GPA like the breast, skeletal system, orbit and eye, heart and vessels, central nervous system, urogenital system as well as endocrine and gastrointestinal tract involvement.