IgG4-Related Disease Presenting as a Soft Tissue Tumor Affecting Skeletal Muscle: A Case Report

Abstract

Background: IgG4-related disease is a systemic lymphoproliferative syndrome that shows IgG4-producing plasma cell expansion in affected organs with fibrotic or sclerotic changes. The lacrimal glands, salivary glands and pancreas are typically affected. We report a case of IgG4-related disease presenting a soft tissue tumor affecting skeletal muscle. Case Report: A 32-year-old man presented a soft tissue mass in his left arm. Magnetic resonance imaging revealed a spindle like, peripheral mass, in the lateral head of the triceps of his left arm. Tru-Cut Biopsy provided the diagnosis of IgG4-related disease affecting skeletal muscle. Glucocorticoid treatment was effective. Conclusion: To our knowledge, this is the first reported case of IgG4-related disease affecting skeletal muscle and presenting a soft tissue mass.

Unusual Manifestation of Immunoglobulin G4-Related Disease Involving the Upper Arm: A Case Report

“…IgG4-RD typically affects middle- to elderly aged men, with an onset at 50–70 years ( 1 2 ). To our knowledge, this is the first case of a patient with IgG4-RD presenting as a soft tissue mass in the subcutaneous layer, describing radiologic features on US and MRI ( Table 1 ) ( 3 4 5 6 ).…”

Immunoglobulin G4‐related disease: a rare disease with an unusual presentation

“…IgG4‐RD can virtually occur in any organ of the body with the most common sites as the salivary glands, periorbital tissues, pancreas, biliary tree, kidneys, lungs, lymph nodes, breast, aorta, thyroid, prostate, and skin . From our review of literature, this is the second known occurrence of IgG4‐RD in the musculature . In light of these rare incidences, patients with associated autoimmune diseases, presenting with myalgias of unknown origin that may be accompanied by swelling, discomfort, or general unease in a particular group of muscle should prompt the physician to include IgG4‐RD in the evaluation of their differentials.…”