case_images: PMC10927231_01
case_images: A magnetic resonance imaging finding at the initial visit showed an 11-mm mass lesion in the sella turcica. (a) Coronal T1- and (b) T2-weighted images, along with (c) sagittal T1- and (d) T2-weighted images.
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case_images: PMC10927231_01_SNI-15-69-g001.jpg
case_images: F1
case_images: Pituitary adenomas and RCC were suspected [Figure 1].
case_images: Magnetic resonance imaging findings when the headache worsened showed growth in tumor size. (a) Coronal T1- and (b) T2-weighted images, along with (c) sagittal T1- and (d) T2-weighted images showed a mixture of hypointense and hyperintense signals. Mucosal thickening was observed in the sphenoid sinus (arrows in b and d).
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case_images: F2
case_images: Head MRI revealed mild enlargement of the lesion and sphenoid sinus mucosal thickening, leading to the diagnosis of pituitary apoplexy [Figure 2].
case_images: Magnetic resonance imaging findings at the time of fever: (a) coronal; (b) sagittal contrast-enhanced T1-weighted images revealed a ring-shaped contrast enhancement that partially extended into the third ventricle (arrow in b); and (c) coronal diffusion-weighted imaging showed a high signal intensity.
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case_images: PMC10927231_01_SNI-15-69-g003.jpg
case_images: F3
case_images: Two days after visiting the emergency outpatient, due to persistent symptoms and having also started vomiting, the patient was reassessed by MRI, revealing a pituitary cystic mass with a ring-shaped contrast enhancement that partially extended into the third ventricle and increased signal intensity on diffusion-weighted imaging (DWI) [Figure 3].
case_images: Intraoperative findings of the patient: (a) the sphenoid sinus mucosa was thickened. (b) When the thickened pituitary gland was incised, a yellowish-brown content was drained (arrow). (c) We biopsied the fibrous marginal tissue.
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case_images: PMC10927231_01_SNI-15-69-g004.jpg
case_images: F4
case_images: Intraoperative findings showed that the sphenoid sinus mucosa was thickened [Figure 4a]. When the pituitary gland was incised, a yellowish-brown content was drained [Figure 4b]. The tissue surrounding the cyst was degenerated and sclerotic; fibrous tissue was collected from the cyst margins and near the pituitary stalk [Figure 4c].
case_images: Microscopic findings. (a) A cystic lesion was covered with ciliated columnar and stratified squamous epithelium. (b) The surrounding cyst showed inflammatory cells infiltrate, mainly consisting of lymphocytes and plasma cells with a few eosinophils and (c) neutrophils.
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case_images: F5
case_images: Storiform fibrosis was not observed [Figure 5a-c].
case_images: Immunostaining findings of the patient: (a) immunoglobulin (IgG) and (b) IgG4. The IgG4-positive plasma cells were 50/high-powered field or higher, and the IgG4/IgG-positive cell ratio was approximately 30-40%.
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case_images: F6
case_images: Immunohistochemical analysis showed more than 50 immunoglobulin G4 (IgG4)-positive plasma cells per high-power field and an IgG4/IgG ratio of 30-40%, thus close to fulfilling the histopathological diagnostic criteria for IgG4-RH [Figure 6].
case_images: A magnetic resonance imaging finding three months after surgery: (a) coronal and (b) sagittal sections of contrast-enhanced T1-weighted images. The cystic lesions and mass in the sella turcica disappeared.
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case_images: PMC10927231_01_SNI-15-69-g007.jpg
case_images: F7
case_images: The patient was prescribed prednisolone (45 mg/day) immediately after the diagnosis, and the lesions shrank promptly [Figure 7].