Adrenal lesion as first manifestation of IgG4-related sclerosing disease

Clinical History

A 20-year-old man with sporadic and non incapacitating mild dorsolumbar pain over the last 3 months takes some routine exams. Abdominal ultrasonography reveals a nodule in the right adrenal gland. Physical examination and laboratory tests were normal.

Imaging Findings

Abdominal ultrasonography revealed a 5cm heterogeneous nodule in the right adrenal gland. Abdominal CT characterization showed a hypoattenuating solid nodular lesion (CT attenuation superior to 10HU on non-contrast scan), with peripheral enhancement after contrast administration and a wash-out less than 60%. MRI characterization was suggested, revealing slight hypointensity to the renal parenchyma in T1 weighted images and marked hyperintensity in the central area in T2 weighted images, without signal loss in out-of-phase images. Dynamic contrast-enhanced study showed heterogeneous enhancement by gadolinium. Peri-adrenal fat was intact. Report suggested these aspects to be compatible with atypical lesion, probably adrenal carcinoma or metastasis. After right adrenalectomy, postoperative histopathological report disclosed medullary destruction by an inflammatory lesion consisting of lymphoplasmocytic infiltration, reactive lymphoid follicles with many plasmocytes and focal vascular damage, all in a sclerofibrotic background. Increased number of IgG4+ cells was detected (more than 50% of total plasmocytes). No neoplastic tissue was found.

Discussion

IgG4-related disease (IgG4RD) is a fibrosing inflammatory disease characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells.
It is frequently systemic, many patients with this condition having lesions in several organs, either synchronously or metachronously, other patients showing involvement of one single organ. Autoimmune pancreatitis is the most common manifestation, presenting with jaundice, abdominal discomfort or, sometimes, severe abdominal pain. [1] But numerous extrapancreatic organs may be involved, such as the bile ducts, gallbladder, kidneys, retroperitoneum, thyroid, salivary glands, lung, mediastinum, lymph nodes, mesentery, blood vessels, lungs, orbits and prostate. [1, 2] The severity of fibrosis is dependent on the individual organs involved.
Clinical symptoms and imaging findings depend on the location of the lesion and the severity of fibrosis is dependent on the individual organs involved.
Adrenal involvement has not yet been referenced in the available literature.
The disease affects predominantly middle age men, and sometimes is misdiagnosed as being a pseudolymphoma or an inflamatory pseudotumor.
At present, the pathogenetic mechanism and underlying immunological abnormalities in IgG4RD remain unclear. Diagnostic criteria have not yet been established because IgG4RD may occur in a variety of organs, so comprehensive discussions with the cooperation of clinicians from several specialized fields is needed to establish uniform diagnostic criteria (the Research Program for Intractable Disease Ministry of Health, Labor and Welfare Japan has recently proposed Guidelines for diagnosis of IgG4RD) [3, 4].
IgG4RD usually responds dramatically well to corticosteroid therapy, often within a few weeks, but recurrence and relapse occur following the early reduction or withdrawal of prednisone.
Treatment guidelines to establish initial doses of steroids, tapering procedures, and maintenance doses have not yet been developed.

Differential Diagnosis List

Final Diagnosis

IgG4-related sclerosing disease

URL:	https://eurorad.org/case/11230
DOI:	10.1594/EURORAD/CASE.11230
ISSN:	1563-4086