IgG4-related intracranial disease

Abstract

IgG4-related disease (IgG4-RD) is a multi-organ chronic inflammatory process caused by infiltration of IgG4-positive plasma cells in one or more organs. Intracranial involvement has only recently become better recognized. Our case series adds to the growing literature on the varying presentations of intracranial IgG4 by describing the clinical and imaging findings of three patients who presented to our institution with intracranial involvement. Our first patient presented with a mass-forming IgG4 pachymeningitis mimicking a sphenoid wing meningioma, which is to our knowledge the largest mass-forming pachymeningitis published in the literature. Our second case depicts another presentation of extensive IgG4 pachymeningitis involving both cavernous sinuses and surrounding Meckel's caves. The third case describes a patient with presumed lymphocytic hypophysitis, which was later determined to be IgG4-related hypophysitis with concomitant pachymeningitis and perineural spread along the optic nerves. The delayed diagnoses in our cases illustrates the diagnostic challenge that clinicians face in differentiating intracranial IgG4-RD from other infiltrative diseases such as sarcoidosis, granulomatous disease, tuberculosis and lymphoma. Earlier consideration of IgG4-related hypophysitis and hypertrophic pachymeningitis in the differential diagnosis can prevent significant morbidity including unnecessary surgical intervention and organ failure secondary to extensive fibrosis.

Successful treatment of IgG4‐related hypertrophic pachymeningitis with induction rituximab and dexamethasone followed by maintenance rituximab

“…6,7 Intracranial involvement is rare and most commonly involves hypertrophic pachymeningitis and hypophysitis. 8 In a Japanese survey, the prevalence of hypertrophic pachymeningitis was about 1 case per 1 000 000 with 8.8% of the cases having IgG4RD as the underlying etiology. 9 Similar to our patient, it is more commonly seen in males, at a median age of 53 years.…”

“…IgG4RD is a rare polyclonal lymphoproliferative disorder, 1 which commonly involves the pancreas, lungs, thyroid gland, lymph nodes, extra pancreatic bile ducts, retroperitoneum, aorta, and lacrimal and salivary glands 6,7 . Intracranial involvement is rare and most commonly involves hypertrophic pachymeningitis and hypophysitis 8 . In a Japanese survey, the prevalence of hypertrophic pachymeningitis was about 1 case per 1 000 000 with 8.8% of the cases having IgG4RD as the underlying etiology.…”

IgG4-Related Inflammatory Pseudotumor Involving the Clivus: A Case Report and Literature Review

“…For lesions in the nervous system, IgG4-RD is relatively common in the orbit and pituitary and is characterized by a variety of histological manifestations (19). Based on previous reports (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14), MR of the lesion usually demonstrated iso-signal intensity in T1-weighted imaging and low or iso-signal intensity in T2-weighted imaging, and intense enhancement was observed after gadolinium-enhanced T1weighted imaging. Therefore, it is difficult to determine whether an infiltrating soft tissue mass is a IgG4-related inflammatory pseudotumor, a malignant tumor or a meningioma.…”

“…The preoperative diagnosis of the disease is very important as IgG4-related inflammatory pseudotumors are more likely sensitive to steroid therapy but not surgery. Here, we report a rare case of an IgG4-related inflammatory pseudotumor in the middle of the upper clivus region, mimicking meningioma, and review the literature on such cases (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). We hope to highlight the importance of considering IgG4-related inflammatory pseudotumors as a differential diagnosis in patients presenting with clivus lesions.…”

“…Although intracranial hypophysitis is well known and relatively common, IgG4-related disease (IgG4-RD) is very rare and characterized histologically by the presence of acute or chronic inflammatory swellings of involved organs with increasing IgG4positive plasma cells and lymphocytes infiltrating the tissues (1). Although several cases of IgG4-related inflammatory pseudotumors have been reported, there are few reports of intracranial IgG4-related inflammatory pseudotumors (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). The preoperative diagnosis of the disease is very important as IgG4-related inflammatory pseudotumors are more likely sensitive to steroid therapy but not surgery.…”