Published online Sep 16, 2022. doi: 10.12998/wjcc.v10.i26.9440
Peer-review started: April 20, 2022
First decision: June 16, 2022
Revised: July 4, 2022
Accepted: August 16, 2022
Article in press: August 16, 2022
Published online: September 16, 2022
Immunoglobin G4 (IgG4)-related hypophysitis (IgG4-RH) is a rare form of IgG4-related disease (IgG4-RD), which often manifests as a single organ disease and is easily misdiagnosed as a pituitary tumor clinically and by imaging. There are few reports of imaging findings of IgG4-RH. Therefore, we describe a case of IgG4-RH, which mimicked a pituitary macroadenoma, that was detected by computed tomography (CT) and magnetic resonance imaging (MRI), and review the previous literature in order to further the understanding of IgG4-RH.
A 47-year-old man presented with a history of blurred vision for more than 2 mo, without other symptoms. A preoperative unenhanced CT scan revealed a slightly hyperdense mass in the sellar region measuring 2.5 cm × 2.3 cm × 1.8 cm, with a CT value of 45 HU. T1-weighted imaging (T1WI) and T2-weighted imaging showed iso-hypointensity, and gadolinium contrast-enhanced T1WI showed obvious homogeneous enhancement. The MRI revealed involvement of the pituitary gland and stalk. Preoperative laboratory tests revealed abnormal pituitary hormone levels, including an increased prolactin level, and decreased levels of insulin-like growth factor, dehydroepiandrosterone, and testosterone. The lesion was surgically resected. Postoperative histopathological examination of a tissue sample and an elevated serum IgG4 level confirmed the diagnosis of IgG4-RH. The patient was treated with cortisone acetate postoperatively and made a good recovery without developing any neurological deficit.
An elevated serum IgG4 concentration is the main clue for diagnosis of IgG4-RD. Imaging combined with laboratory testing is useful for preoperative diagnosis of IgG4-RH.
Core Tip: Immunoglobin G4 (IgG4)-related hypophysitis (IgG4-RH) is a rare form of IgG4-related disease, which is easily misdiagnosed as a pituitary tumor. IgG4-RH commonly occurs in middle-aged and older men and is characterized by hypointensity on T2-weighted imaging and homogeneous and obvious enhancement on gadolinium contrast-enhanced T1-weighted imaging, accompanied by hypopituitarism. The imaging findings help to differentiate it from pituitary tumors. An elevated serum IgG4 level is the main clue to the diagnosis of IgG4-RH, and imaging, histopathology, or response to glucocorticoid therapy can be used to confirm the diagnosis.