Thoracic Hyper-IgG4-Related Disease Mimicking Malignant Pleural Mesothelioma

Our plain-English summary of Thoracic Hyper-IgG4-Related Disease Mimicking Malignant Pleural Mesothelioma, by F. Lococo, T. Di Stefano, C. Rapicetta, et al (Lung, 2019).

The study

• Authors: F. Lococo, T. Di Stefano, C. Rapicetta, R. Piro, M.C. Gelli, F. Muratore, T. Ricchetti, S. Taddei, M. Zizzo, A. Cesario, N. Facciolongo, M. Paci
• Journal: Lung
• Published: 2019;197(3):387-390
• Type of article: Case report
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We report a rare case of a IgG4-related disease presenting with recurrent pleural effusion, pleural thickness and multiple mediastinal lymphadenopathies and no involvement of other extrathoracic organs. A 65-year-old man with a previous asbestos exposure presented with cough and pain discomfort. A large right pleural effusion was detected and evacuated (siero-haematic liquid). With the suspicious of a pleural mesothelioma, a CT-scan before and a 18F-FDG PET/CT-scan later were performed revealing multiple pleural thickenings and multiple mediastinal lymphadenopathies with radiotracer uptake. EBUS-TBNA EBUS-TBNA did not result in a formal pathological diagnosis; thus, multiple pleural biopsy were performed via right thoracoscopy. At pathology the pleura was markedly thickened by a chronic fibroinflammatory process with scattered lymphoid follicles and a large number of mature plasma cells. Immunohistochemistry shows a mixed B (CD20+) and T (CD3+) population of lymphocytes, without light chain restriction and an increased number of IgG4-positive plasma cells. A presumptive diagnosis of IgG4-related disease was formulated. Total body CT-scan excluded other organ involvement. Blood test showed elevated serum IgG4 concentrations (253 mg/dL) and mild elevation of acute-phase reactants (C-reactive protein 10.7 mg/L). Autoimmune profile was negative. A diagnosis of definite IgG4-related disease was made, and treatment with prednisone 50 mg/day was started.

In plain English

This case report describes a 65-year-old man, a heavy smoker with a previous asbestos exposure, who came to the authors' hospital with cough, six weeks of worsening breathlessness on exertion, and right chest discomfort. Scans showed fluid around the right lung, several areas of thickened pleura (the lung lining) and enlarged chest lymph nodes. Tests on the drained fluid found no infection or cancer cells. Doctors suspected pleural mesothelioma. A PET scan showed intense uptake in the chest lymph nodes, and a needle biopsy was inconclusive. At thoracoscopy the pleura looked highly indicative of malignant pleural mesothelioma, but biopsies instead showed chronic scarring and inflammation with many IgG4-positive plasma cells. Blood IgG4 was raised (253 mg/dL), and no other organs were involved. The patient was diagnosed with IgG4-related disease and started on prednisone 50 mg/day. The article does not report how the patient fared. The authors concluded that doctors should keep this rare condition in mind when the cause of pleural inflammation is unclear.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case report of a single patient (published as a 'Lung Images' item)
• Who was studied: One 65-year-old man, a heavy smoker, seen at the authors' hospital (the authors are based in Reggio Emilia, Italy). He had cough, a 6-week history of progressive exertional breathlessness, and right chest discomfort. Dates are not given.
• Exposure: A previous asbestos exposure. The article gives no fiber type, job, product, duration or dose. The patient was also a heavy smoker.
• Main results:
  • About 1600 cc of blood-tinged fluid was drained from around the right lung. Laboratory analysis showed it was an exudate, and culture and cytology were negative.
  • Mesothelioma was suspected. A PET/CT scan showed intense uptake (SUVmax 7.3) in the mediastinal lymph nodes and mild uptake in the thickened pleura at the base.
  • A needle biopsy through an airway scope (EBUS-TBNA) showed a nonspecific chronic inflammatory process but gave no formal diagnosis.
  • At thoracoscopy, the appearance of the pleura was described as highly indicative of malignant pleural mesothelioma. Large pleural biopsies were taken from multiple sites.
  • The biopsies showed a chronic fibroinflammatory process with storiform pattern fibrosis. There was a mean of 70 IgG4-positive plasma cells per high-power field, and the ratio of IgG4-positive to IgG-positive plasma cells was greater than 30%.
  • Serum IgG4 was elevated at 253 mg/dL, and C-reactive protein was mildly elevated at 10.7 mg/L. The autoimmune profile was negative.
  • Total body CT and PET/CT scans excluded involvement of other organs.
  • A diagnosis of definite IgG4-related disease was made using the 2011 comprehensive diagnostic criteria, and prednisone 50 mg/day was started. No treatment outcome is reported.
• The authors' conclusion: The authors concluded that physicians should keep IgG4-related disease in mind when diagnosing pleuritis of unknown origin, as in this case, where asbestos exposure and the scan results suggested malignant pleural disease. In their view, the correct diagnosis matters because corticosteroids are generally not given before a cancer is excluded, and most patients with IgG4-related disease respond to corticosteroids at first.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Pleural Effusion, Pleural Thickness, Asbestos Exposure, Pleural Thickening, Pleural Biopsy, Thoracoscopy, Pathology.

Related studies

• IgG4-related pleural disease with aortitis and submandibular glands involvement successfully treated with corticosteroid: case-based review — S. Okamoto, H. Tsuboi, et al. (2020)
• IGG4-Related Pleural Bridging Fibrosis, Retrosternal Fibrosclerosis and Retroperitoneal Fibrosis in an Asbestos-Exposed Patient — P.P.T.E.S. Torres, L.B.M. Fonseca, et al. (2019)
• IgG4-Related Lung Disease Exhibiting the Invasion into the Diaphragm: A Case Report — Y. Ono, G. Toyokawa, et al. (2022)
• Computed tomography in the diagnosis of asbestos-related thoracic disease — G. Gamsu, D.R. Aberle, et al. (1989)
• Taking a retrospective look at asbestos-related thoracic disease produces interesting results — E.B. Gottschall (2010)
• Thoracic surgical problems in asbestos-related disorders — E.A. Gaensler, T.C. McLoud, et al. (1985)

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