Persistent Lymphadenopathy due to IgG4-Related Disease

A 28-year-old healthy female presented to her primary care physician with lymphadenopathy, fatigue, malaise, and night sweats. Symptoms persisted despite conservative treatment and eventually the patient underwent multiple lymph node resections and a bone marrow biopsy before a diagnosis of IgG4-related disease (IgG4-RD) was made. IgG4-RD is a relatively new disorder first histopathologically recognized within the last decade. As the disease can affect a single organ or multiple organs, symptoms can vary greatly among patients. With symptoms ranging from mild, such as lower extremity edema, to severe, such as spinal cord compression, IgG4-RD must be considered in appropriate patients. Diagnostic criteria have been proposed based on organ involvement, serum IgG4 levels, and histopathological criteria. Diagnosis can be difficult to make with many studies suggesting different values for diagnostic criteria, such as the level of tissue IgG4+/IgG+ cell ratio to delineate IgG4-RD. Treatment consists of high dose glucocorticoids as a first line therapy with some patients choosing instead to simply undergo observation. This case illustrates the difficulty in diagnosis and the need for increased awareness among medical professionals. 1. Introduction IgG4-RD is a relatively newly classified condition with unifying histopathologic features recognized only since the early 2000s [1]. The disorder is thought to mainly affect middle-aged to elderly men with a median age of onset of 58 years old [2, 3]. Exact incidence and prevalence are difficult to determine as many cases most likely go undiagnosed with limited awareness currently amongst medical professionals. Clinical findings vary by the organ system involved but many times are associated with tissue swelling or enlargement [1]. Due to the variety of clinical presentations, diagnosis can be delayed months to years and result in unnecessary tests and procedures. 2. Case Presentation A 28-year-old female with no significant past medical history presented to her primary care physician with lymphadenopathy, night sweats, fatigue, and malaise. She was treated empirically and partially responded to a short course of glucocorticoids and an antibiotic. When initial laboratory workup was unrevealing for an obvious etiology and symptoms persisted, computed tomography (CT) of the neck and chest with contrast was performed that showed diffuse adenopathy (Figure 1) and hepatosplenomegaly. The patient was referred for lymph node resection that initially revealed only nonspecific B cell proliferation and did not support a