ANCA Negative GPA (Wegener’s Disease) Years after Thymectomy

Abstract

A 78-year-old man with a history of resection of a mediastinal mass in 2008, initially diagnosed as a typical carcinoid tumor, presented 17 years later with a progressively enlarging subcutaneous pectoral mass. Given his oncological history, recurrent malignancy was strongly suspected. However, extensive radiological, histopathological, and immunological investigations demonstrated that the lesion represented antineutrophil cytoplasmic antibody (ANCA)-negative granulomatosis with polyangiitis (GPA). ANCA-negative GPA is an uncommon subtype of this autoimmune small-vessel vasculitis and is often characterized by localized disease, predominantly affecting the respiratory tract without renal involvement. This case highlights a rare presentation of ANCA-negative GPA mimicking recurrent thoracic malignancy many years after mediastinal tumor resection. Awareness of such atypical manifestations is essential to avoid misdiagnosis and ensure timely initiation of appropriate immunosuppressive therapy.