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Neuroradiology Case of the Week
Case 364
November 2008
Daniel Ginat MD, MS, Rajiv Mangla MD,
and Per-Lennart Westesson, MD, PhD, DDS
Clinical
Presentation: Patient is a 55-year-old male who presented with with syncope and collapse.
Imaging Findings: Non-contrast Head CT: Enlarged hyperdense sellar/suprasellar mass with expansion of sella turcica. The mass contains hyperdense areas suggestive of hemorrhage (Fig. 1).
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Figure 1: Axial head CT demonstrates a hemorrhage in the pituitary macroadenoma.
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Figure 2: Coronal T1-weighted MR without contrast demonstrates focal acute hemorrhage (arrow).
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Figure 3: Sagittal T1-weighted MR with contrast demonstrates enhancement of the pituitary adenoma, which assumes a classic "figure of eight" configuration.
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| Figure 4: Coronal T1-weighted MR with contrast again illustrates heterogeneous enhancement of the tumor. |
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| Figure 5: Axial gradient echo MR sequence reveals acute/hyperacute apoplexy and possible cystic change attributable to necrosis. |
Diagnosis: Pituitary Adenoma Apoplexy
Discussion: Pituitary apoplexy is a potentially life-threatening condition that consists of acute onset of headache, opthalmoplegia, photophobia, vision loss, vomiting, or amenorrhea secondary to hemorrhage or infarction of the pituitary [1]. The tenuous vascular supply of pituitary adenomas predisposes to apoplexy which occurs in an estimated 10 to 15% of cases [2]. Males are more frequently affected than females. Other causes of pituitary apoplexy include treatment with bromocriptine, trauma, radiation, Sheehan syndrome (postpartum pituitary necrosis), and Korean hemorrhagic fever [1,2].
MRI is the modality of choice for evaluating pituitary apoplexy. Apoplexy in adenomas typically demonstrates a large mass with high signal intensity on T1 and T2 [3]. In contrast, apoplexy in Sheehan syndrome does not produce pituitary enlargement. Lack of hemosiderin deposition is characteristic of pituitary hemorrhage [1]. Early apoplexy may manifest as high signal intensity on diffusion weighted imaging [3]. Reduction of the pituitary gland volume may be a sequela of apoplexy [3]. Cerebral infarction represents a very rare complication of pituitary apoplexy [4].
The differential diagnosis for pituitary apoplexy includes Rathke’s cleft cyst, craniopharyngioma, and pituitary metastasis. Rathke’s cleft cysts are usually asymptomatic and display high signal on T1 and low signal on T2. Craniopharyngiomas often present with bilateral hemianopsia and imaging will demonstrate prominent cystic and calcified components.
References:
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Grossman R, Yousem D. Neuroradiology, The Requisites. 2nd Ed. Mosby, Philadelphia, 2003: 795-796.
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Rennert J, Doerfler A. Imaging of sellar and parasellar lesions. Clin Neurol Neurosurg. 2007 Feb;109(2):111-24. [PubMed]
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Pisaneschi M, Kapoor G.Imaging the sella and parasellar region.Neuroimaging Clin N Am. 2005 Feb;15(1):203-19. [PubMed]
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Akutsu H, Noguchi S, Tsunoda T, Sasaki M, Matsumura A. Cerebral infarction following pituitary apoplexy--case report. Neurol Med Chir (Tokyo). 2004 Sep;44(9):479-83. [PubMed]
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