Thoracic Involvement in IgG4-Related Disease

Abstract

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder that has been recognized to involve virtually any organ in the body and typically manifests mass-like lesions (tumefactive). Although initial reports of this disease (autoimmune pancreatitis [AIP]) were described in the Japanese population, it has since been reported worldwide. It is most commonly seen in adults of middle age or older, more often men than women. The pathogenesis of IgG4-RD is largely unknown, but genetic factors, microorganisms, and autoimmunity are thought to play important roles. Serum IgG4 concentration is elevated in the majority of patients with IgG4-RD but is a nonspecific finding. Characteristic histopathologic features include dense lymphoplasmacytic infiltrate, fibrosis (often in storiform pattern), and obliterative phlebitis. Lung involvement in IgG4-RD was first reported in 2004 in two patients with AIP and coexisting interstitial lung disease. Since then, a wide spectrum of intrathoracic involvement has been reported and includes not only parenchymal lung diseases but also pleural, airway, vascular, and mediastinal lesions. Thoracic involvement in IgG4-RD is often found incidentally during the workup of extrathoracic lesions but can sometimes be the presenting abnormality. The diagnosis of IgG4-RD requires correlation of clinical, laboratory, imaging, and histopathologic features. Glucocorticoids are the first-line therapy but other options including B cell depletion are being investigated. IgG4-RD is generally associated with an indolent clinical course and most patients improve with glucocorticoid therapy.

Supraglottic Localization of IgG4-Related Disease—Rare and Challenging Equity

“…Previously, the disease was referred to as autoimmune pancreatitis, retroperitoneal fibrosis, Kuttner tumors, Mikulicz’s disease, inflammatory pseudotumor, aortitis, Riedel thyroiditis and lymphadenopathy [ 1 ]. The disease may manifest in any location that results in a large spectrum of involved organs: the thyroid, kidneys, prostate, skin, lungs and others [ 2 , 3 , 4 ]. The disease is often described as subacute with varied symptoms depending on the organ affected.…”

Inflammation of the Pleural Cavity: A Review on Pathogenesis, Diagnosis and Implications in Tumor Pathophysiology

“…Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory disease with systemic manifestations with an estimated incidence in Japan from 0.258 to 1.08/100,000, showing male predominance and an onset after 40 years [34]. Its pathogenesis remains unclear, but a type-2 helper cell (Th2) immune response is highly implicated [34]. Thoracic involvement occurs in almost half of the patients [34].…”

“…Its pathogenesis remains unclear, but a type-2 helper cell (Th2) immune response is highly implicated [34]. Thoracic involvement occurs in almost half of the patients [34]. Similarly, in a UK-based cohort of 53 IgG4-RD patients almost half showed thoracic involvement, with mediastinal lymphadenopathy being the most common, but a variation of clinical manifestations, such as interstitial lung disease, pleural thickening and effusion being described [35].…”

“…Pleural IgG4-RD presents as nodular or diffuse pleural thickening and pleural effusion with or without underlying parenchymal disease [34]. Histopathological sections of IgG4-RD show storiform fibrosis, dense lymphoplasmocytic infiltrate, obliterative phlebitis, and high IgG4+ plasma cells with the proposed cut-offs varying with the site of involvement; in the lung and pleura, it is suggested to be at >50 IgG4+ plasma cells/high power field for surgical biopsies and >20 IgG4+ plasma cells/high power field for nonsurgical biopsies, and an IgG4+/IgG+ ratio > 40% [34].…”

A case with multiple nodules and mucosal oedema of the trachea and both bronchi induced by IgG4-related disease

“…However, 75% of patients with IgG4-related lung disease (IgG4-RLD) are asymptomatic and are incidentally diagnosed through chest computed tomography (CT) [ 1 ]. The main symptoms in symptomatic patients are nasal congestion, rhinorrhoea, chest pain, and cough (sometimes similar to asthma) [ 1 , 4 ]. The most frequent lesion on chest CT is hilar mediastinal lymphadenopathy [ 2 ].…”