Successful treatment of a patient with IgG4-related disease with a paravertebral mass lesion

IgG4-related fibrosing mediastinitis diagnosed with computed tomography-guided percutaneous needle biopsy: Two case reports and a review of the literature

RATIONALE

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory disease characterized by elevated serum IgG4 levels with infiltration of IgG4+ plasma cells and severe fibrosis in affected tissues. Recently, idiopathic fibrosing mediastinitis (FM), an extremely rare fibroinflammatory disorder, has been recognized as a form of IgG4-RD. As IgG4-RD can be treated by glucocorticoids, identification of the etiology of FM by surgical biopsy is essential; however, mediastinal biopsy is often difficult. We report 2 cases of IgG4-related FM successfully diagnosed with computed tomography (CT)-guided percutaneous needle biopsy.

PATIENT CONCERNS

Case 1 was a 66-year-old woman with elevated serum C-reactive protein without any symptoms and case 2 was 78-year-old woman with abnormal mediastinal contour on chest x-ray. By further work-up, both cases were found to have mediastinitis accompanied by elevated serum IgG4. CT-guided percutaneous needle biopsy revealed massive infiltration of IgG4+plasma cells along with storiform fibrosis.

DIAGNOSIS

IgG4-related FM.

INTERVENTIONS

Glucocorticoid therapy.

OUTCOME

The treatment resulted in significant improvement of the lesions after 3 months.

LESSONS

Early recognition and diagnosis of IgG4-related FM is essential because a delay in appropriate treatment initiation leads to progressive fibrosis with irreversible organ damage and poor prognosis. Our cases highlight CT-guided percutaneous needle biopsy as a promising option for histological examination in patients with IgG4-related FM.

Thoracic Paravertebral Mass as an Infrequent Manifestation of IgG4-Related Disease

Case

A 50-year-old African American male presented with abdominal pain and significant weight loss. On physical examination, he had parotid and submandibular gland enlargement associated with right eye proptosis. Computed tomography showed a thoracic paravertebral soft tissue mass, enlarged lymph nodes, and ascending aortic aneurysm. Laboratory results were remarkable for elevated total IgG and IgG4 subclass. The submandibular gland pathology revealed chronic sclerosing sialadenitis, with a large subset of inflammatory cells positively staining for IgG4. The histology of the paravertebral mass demonstrated fibrosclerosis with increased lymphocytic infiltrate, associated with increased IgG4 plasma cells. He was diagnosed with immunoglobulin G4-related disease (IgG4-RD). Steroid therapy initially yielded improvement; however, after steroids were stopped, there was disease recurrence. Prednisone was restarted, and the plan was to start him on rituximab. Interestingly, the patient's brother also had IgG4-RD.

Conclusion

IgG4-RD can present as a paravertebral mass which is usually responsive to steroids; however, recurrent and resistant disease can be seen for which steroid-sparing agents such as rituximab should be considered. In addition, to the best of our knowledge, this is the first reported case of IgG4-RD in two family members presenting as a paravertebral mass, highlighting an exciting area for more research in the future.

Antineutrophil cytoplasmic antibody positivity in IgG4-related disease: A case report and review of the literature

BACKGROUND

IgG4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by serum IgG4 elevation and tissue infiltration of IgG4-positive plasma cells. Substantial overlap between IgG4-RD and antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) exists in terms of organ involvement and histopathological features. A positive ANCA assay is regarded as a highly specific finding in favor of an AAV, and generally influences away from a diagnosis of IgG4-RD. Recent reports, however, have raised the possibility that some patients with IgG4-RD are ANCA positive, thus suggesting reconsideration of the role of ANCA in the diagnostic workup. In the present work, we describe the first case of concomitant biopsy-proven IgG4-RD and granulomatosis with polyangiitis (GPA), demonstrating antiproteinase 3 (PR3) ANCA of the IgG4 subclass in the patient's serum. We also review the literature in order to provide clinicians with tools for interpreting ANCA positivity in IgG4-RD patients.

CASE SUMMARY

A 51-year-old woman was referred for left exopthalmos due to lacrimal gland enlargement and increased serum IgG4 concentration. IgG4-RD was suspected and further imaging studies disclosed multiple pulmonary masses in the right lung. Histological analysis of the left lacrimal gland was diagnostic for IgG4-RD, but lung biopsy showed typical features of GPA. ANCA assay was positive for anti-PR3 antibodies. Further immunofluorescence studies demonstrated anti-PR3 antibodies of IgG1 and IgG4 subclass. Treatment with rituximab induced swift remission of both IgG4-RD and GPA manifestations. We identified 9 other reports of patients with IgG4-RD and positive ANCA in the English literature, 5 cases with biopsy-proven IgG4-RD and 4 cases in whom IgG4-RD was diagnosed presumptively. Four patients had also histological evidence of concomitant AAV.

CONCLUSION

The present work demonstrates that ANCA positivity in patients with biopsy-proven IgG4-RD should prompt the exclusion of a concomitant vasculitic process; a positive ANCA does not exclude the diagnosis of IgG4-RD; confirmation through immunoenzymatic assays of the ANCA specificity, clinical-pathological correlation, and histopathological evaluation remain crucial steps for the differential diagnosis between AAV and IgG4-RD.

PET/CT in Patients with Sarcoidosis or IgG4 Disease

Sarcoidosis as a distinct disease entity was diagnosed more than 100 years ago. The signs and symptoms of the disease are nonspecific, posing a challenge for early and accurate diagnosis. IgG4 disease or syndrome has various clinical manifestations, such as sclerosing pancreatitis, sclerosing cholangitis, prostatitis, tubulointerstitial nephritis, interstitial pneumonia, and enlargement of salivary glands. This article discusses the role of the different diagnostic imaging modalities in sarcoidosis and IgG4 disease, including radiographs, computed tomography, magnetic resonance imaging, and conventional nuclear medicine, with a special emphasis on positron emission tomography as a superior modality for assessing these inflammatory diseases.