Deconstructing IgG4-related disease involvement of midline structures: Comparison to common mimickers.

OBJECTIVE: A series of destructive and tumefactive lesions of the midline structures have been recently added to the spectrum of IgG4-related disease (IgG4-RD). We examined the clinical, serological, endoscopic, radiological, and histological features that might be of utility in distinguishing IgG4-RD from other forms of inflammatory conditions with the potential to involve the sinonasal area and the oral cavity. METHODS: We studied 11 consecutive patients with erosive and/or tumefactive lesions of the midline structures referred to our tertiary care center. All patients underwent serum IgG4 measurement, flow cytometry for circulating plasmablast counts, nasal endoscopy, radiological studies, and histological evaluation of tissue specimens. The histological studies included immunostaining studies to assess the number of IgG4 + plasma cells/HPF for calculation of the IgG4+/IgG + plasma cell ratio. RESULTS: Five patients with granulomatosis with polyangiitis (GPA), three with cocaine-induced midline destructive lesions (CIMDL), and three with IgG4-RD were studied. We found no clinical, endoscopic, or radiological findings specific for IgG4-RD. Increased serum IgG4 and plasmablasts levels were not specific for IgG4-RD. Rather, all 11 patients had elevated blood plasmablast concentrations, and several patients with GPA and CIMDL had elevated serum IgG4 levels. Storiform fibrosis and an IgG4+/IgG + plasma cell ratio >20% on histological examination, however, were observed only in patients with IgG4-RD. CONCLUSIONS: Histological examination of bioptic samples from the sinonasal area and oral cavity represents the mainstay for the diagnosis of IgG4-RD involvement of the midline structures.

Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Positive Otitis Media and Rhinosinusitis With Pathological Features of Immunoglobulin G4-Related Disease: A Case Report.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have different clinical and pathological features. However, differentiation between these 2 disorders is sometimes difficult. OBJECTIVE: To report a case involving a patient with characteristics of both IgG4-RD and AAV. METHODS: Case report with literature review. RESULTS: We report a case of myeloperoxidase-ANCA-positive otitis media and rhinosinusitis with pathological features of IgG4-RD in a 73-year-old man. The patient was first clinically suspected to have granulomatosis with polyangiitis. All of the main characteristic pathological features of IgG4-RD were present: dense lymphoplasmacytic infiltration, increased numbers of IgG4-positive plasma cells, storiform-type fibrosis, and obliterative phlebitis. CONCLUSIONS: The simultaneous presence of the characteristics of both IgG4-RD and AAV makes diagnosis and treatment difficult.

Multiple mucocutaneous ulcers associated with cocaine-induced midline destructive lesions.

Cocaine-induced midline destructive lesions (CIMDL) occur in a small subset of cocaine users, who clinically present with inflammation and necrosis of facial midline structures such as the palate, nasal septum, turbinates, and sinuses. We present a patient with CIMDL occurring concomitantly with ulcers on the cheek and upper trunk. Multiple biopsy specimens from the cutaneous and mucosal lesions consistently showed a dense dermal/submucosal infiltrate of neutrophils and plasma cells, without vasculitis or thrombosis. The ulcers resolved following cessation of cocaine use.