J Korean Soc Radiol.  2011 Apr;64(4):303-307. 10.3348/jksr.2011.64.4.303.

Inflammatory Pseudotumor of the Pituitary Gland Mimicking a Pituitary Adenoma: A Case Report

• Kim DM
• Yu IK
• Kim HK
• Son HJ

• KMID: 1443531
• DOI: http://doi.org/10.3348/jksr.2011.64.4.303

Abstract

A 38-year-old man was admitted to our hospital with diplopia. The patient had a relatively well-defined pituitary mass with high cellularity as well as weaker enhancement on imaging modalities including computed tomography (CT) and magnetic resonance imaging (MRI), than a typical pituitary adenoma. The distinction between a pseudotumor and an invasive neoplasm is very difficult before biopsy. In this case report, we discuss the characteristic imaging features of a fibrosing inflammatory pseudotumor of the pituitary gland.

MeSH Terms

Adult
Angiography
Biopsy
Diplopia
Granuloma, Plasma Cell
Humans
Magnetic Resonance Imaging
Pituitary Gland
Pituitary Neoplasms
Tomography, X-Ray Computed

Figure

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  Fig. 1 A 38-year-old man presenting with ophthalmoplegia and diplopia that aggravated the left lateral gaze. A. Pre-contrast CT image showing a well defined, homogeneously high attenuated lesion in the sella and parasellar regions. B. Postcontrast CT image shows homogeneously well enhanced lesion with encasement of both cavernous ICA. C. Sagittal bone algorithm CT image showing permeative bone erosion of the sellar floor and dorsum sella (arrows).

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  Fig. 2 A. T1-weighed axial MR image showing a well defined iso-signal intensity lesion, involving the sellar and parasellar region. B. T2-weighted axial MR image showing a well defined low signal intensity lesion, involving the sellar and parasellar region. C. Contrast-enhanced T1-weighted axial MR image showing homogenous enhancement of the lesion with bilateral involvement of the cavernous sinuses associated with encasement of the both cavernous ICA (arrows). D. Contrast-enhanced T1-weighted sagittal MR image shows the caudal portion of the lesion extending to the retrosellar region. Note that minimal suprasellar bulging contour of the mass was evident despite the involvement of both cavernous sinuses.

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  Fig. 3 A. Left ICA angiogram showing tumor staining in the venous phase, similar to a meningioma, but with a weaker degree of demarcation than staining of the meningioma. B. Left ICA angiogram showing focal severe stenosis of the Lt. distal cavernous ICA in the arterial phase. C. Photomicrograph of the inflammatory pseudotumor (inflammatory myofibroblastic tumor) of the pituitary TSA specimen showing underlying collagenous dense fibrous tissue (asterisk) which was infiltrated by prominent inflammatory infiltrates (mainly plasma cells, lymphocytes, and histiocytes) with a Russel body (small, pink colored, spherical intracytoplasmic hyaline body, arrows) (H-E stain, magnification, × 400).

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