Isolated necrotizing scleritis revealing silent pulmonary granulomatosis with polyangiitis: A case report of rare diagnostic clue

Rationale

Granulomatosis with polyangiitis (GPA) is a rare, life-threatening vasculitis characterized by necrotizing granulomatous inflammation. Isolated necrotizing anterior scleritis as the sole initial manifestation is distinctly rare. The presence of a clinically silent pulmonary mass without ear, nose, and throat or renal involvement makes this presentation exceptional and diagnostically challenging. Patient concerns: A 31-year-old man presented with recurrent unilateral necrotizing anterior scleritis resistant to corticosteroids and immunosuppressants, without systemic symptoms. Diagnoses: This single-patient case report, prepared in accordance with CAse REport guidelines, revealed mildly elevated anti-proteinase 3 antibodies (25 AU/mL) in laboratory tests. Chest computed tomography unexpectedly showed a 5-cm solitary pulmonary mass. Histopathology demonstrated necrotizing granulomatous inflammation with multinucleated giant cells and vasculitis, confirming GPA.