Challenges in diagnosis of limited granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (GPA) is an orphan disease with multifaceted clinical presentations and delayed diagnosis. Given the risks of delayed diagnosis and treatment, improving clinicians' awareness of atypical course of this disease is critically important. The aim of this report is to analyze a case of delayed diagnosis of GPA in view of similar publications. We analyzed articles retrieved from Scopus and MEDLINE/PubMed. The following keywords were used: "granulomatosis with polyangiitis", "Wegener granulomatosis", and "diagnostic errors". All case studies that fulfilled the Chapel Hill Consensus Conference and the American College of Rheumatology GPA criteria were retrieved. We report a 71-year-old female patient with a facial defect in the nasal region, nasal congestion, and serosanguineous discharge. Her final diagnosis of GPA was reached after a series of incorrect diagnoses in the past 40 years. A deforming facial lesion developed during this period of uncertainty and absence of appropriate treatment. This patient presented with atypical features of laboratory and instrumental examinations. Anti-neutrophil cytoplasmic antibodies (ANCA) were negative, while rheumatoid factor (RF; 46.3 IU/mL) and anti-citrullinated protein antibody (ACPA; 25.6 IU/mL) were elevated. The histological analysis of the nasal mucous membrane specimen did not indicate definite signs of vasculitis. However, it revealed a granuloma with aggregation of macrophages and massive infiltration of lymphocytes, ruling out previous diagnosis of carcinoma. We analyzed delayed diagnosis of GPA in our patient in the context of 12 previously reported similar cases of limited form of GPA. We emphasize the importance of histological examination for differential diagnosis of GPA.