Satomi Kasashima1,2,3, Atsuhiro Kawashima2,3, Satoru Ozaki1, Toshiyuki Kita4, Tomoyuki Araya4, Yasuhiko Ohta5, Mitsutaka Suzuki5. 1. Department of Clinical Laboratory Science, Kanazawa University, Kanazawa, Japan. 2. Department of Pathology, Kanazawa Medical Center, Kanazawa, Japan. 3. Department of Clinical Laboratory, Kanazawa Medical Center, Kanazawa, Japan. 4. Department of Respiratory medicine, Kanazawa Medical Center, Kanazawa, Japan. 5. Department Thoracic surgery of National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan.
Abstract
OBJECTIVE: Immunoglobulin (Ig)G4-related disease is a recently described systemic immune-mediated fibro-inflammatory disease that frequently occurs in tumorous form. Herein, we elucidated the clinicopathological and cytological characteristics of IgG4-related pleural lesions (PLs). PATIENTS AND METHODS: Among 22 patients with fibro-inflammatory PLs of idiopathic aetiology, eight cases were diagnosed as IgG4-PL and the remaining 14 as non-IgG4-PL according to comprehensive diagnostic criteria for IgG4-related disease. Cell block examination of pleural effusion (CBPE) was performed in five patients with IgG4-PL and in six with non-IgG4-PL. Both groups were compared in terms of clinical presentation, laboratory data, histopathological features of resected pleura, and cytological features of pleural effusion (PE). RESULTS: PE was the most common (six patients, 75%) clinical presentation of IgG4-PL. IgG4-PL comparatively showed significantly more frequent concomitant allergic disease (P = .021), higher serum IgE levels (P = .012), higher adenosine deaminase levels in pleural fluid (P = .005), and rare spontaneous recovery without treatment (P = .046). The IgG4-PL group was histologically characterised by thicker fibrous pleura, storiform fibrosis, and infiltration of regulatory T cells, eosinophils and basophils. Using CBPE, IgG4-PL was cytologically distinct with numerous IgG4+ cells and eosinophils. The cytology of CBPE positively correlated with the histology of pleural tissue in the number of IgG4+ cells and eosinophils (R = .769 and .803, respectively). CONCLUSION: IgG4-PL frequently presents with PE and is histologically and cytologically characterised by abundant infiltration of IgG4+ cells and eosinophils. We believe that CBPE with immunohistochemistry/special staining could assist in the auxiliary diagnosis of IgG4-PL.
OBJECTIVE: Immunoglobulin (Ig)G4-related disease is a recently described systemic immune-mediated fibro-inflammatory disease that frequently occurs in tumorous form. Herein, we elucidated the clinicopathological and cytological characteristics of IgG4-related pleural lesions (PLs). PATIENTS AND METHODS: Among 22 patients with fibro-inflammatory PLs of idiopathic aetiology, eight cases were diagnosed as IgG4-PL and the remaining 14 as non-IgG4-PL according to comprehensive diagnostic criteria for IgG4-related disease. Cell block examination of pleural effusion (CBPE) was performed in five patients with IgG4-PL and in six with non-IgG4-PL. Both groups were compared in terms of clinical presentation, laboratory data, histopathological features of resected pleura, and cytological features of pleural effusion (PE). RESULTS: PE was the most common (six patients, 75%) clinical presentation of IgG4-PL. IgG4-PL comparatively showed significantly more frequent concomitant allergic disease (P = .021), higher serum IgE levels (P = .012), higher adenosine deaminase levels in pleural fluid (P = .005), and rare spontaneous recovery without treatment (P = .046). The IgG4-PL group was histologically characterised by thicker fibrous pleura, storiform fibrosis, and infiltration of regulatory T cells, eosinophils and basophils. Using CBPE, IgG4-PL was cytologically distinct with numerous IgG4+ cells and eosinophils. The cytology of CBPE positively correlated with the histology of pleural tissue in the number of IgG4+ cells and eosinophils (R = .769 and .803, respectively). CONCLUSION: IgG4-PL frequently presents with PE and is histologically and cytologically characterised by abundant infiltration of IgG4+ cells and eosinophils. We believe that CBPE with immunohistochemistry/special staining could assist in the auxiliary diagnosis of IgG4-PL.