Acute airway obstruction revealing granulomatosis with polyangiitis: A case report of a rare isolated laryngeal presentation

Granulomatosis with polyangiitis (GPA) is a rare necrotizing vasculitis predominantly involving the upper respiratory tract, lungs, and kidneys. Isolated laryngeal involvement is rare and may mimic malignancy. We report the case of a 59-year-old man presenting with acute progressive dyspnea and severe airway compromise. Endoscopic examination revealed an infiltrative glotto-subglottic lesion causing marked laryngeal narrowing. Contrast-enhanced cervicothoracic computed tomography demonstrated a heterogeneously enhancing infiltrative soft-tissue mass involving the glotto-subglottic region and anterior commissure without thyroid or cricoid cartilage destruction. Laboratory investigations showed markedly elevated c-ANCA levels. Histopathological examination obtained by suspension microlaryngoscopy confirmed granulomatosis with polyangiitis by demonstrating necrotizing granulomatous inflammation with vasculitic changes. Comprehensive imaging excluded pulmonary, renal, and systemic involvement, supporting the diagnosis of localized laryngeal GPA. The patient was successfully treated with corticosteroids and methotrexate, resulting in complete clinical and radiological remission at follow-up. This case illustrates the diagnostic value of imaging in differentiating inflammatory pseudotumoral vasculitis from invasive laryngeal malignancy. Preservation of the laryngeal cartilaginous framework despite infiltrative soft-tissue thickening may constitute an important radiologic clue favoring GPA. Early recognition and histopathological confirmation are essential to prevent irreversible airway stenosis and unnecessary aggressive surgery.