Pituitary apoplexy is an acute clinical syndrome caused by either hemorrhagic or non-hemorrhagic necrosis of the pituitary gland 2. Although variable, it typically comprises headache, visual deficits, ophthalmoplegia, and altered mental status 7. An existing pituitary macroadenoma is usually present (60-90%) but it has occured with healthy glands in few isolated cases.
The demographics generally follow that of pituitary macroadenomas. Additional predisposing factors include 2:
- medical treatment of a prolactinoma (especially with bromocriptine) 6
- prior irradiation of the mass
- pregnancy (Sheehan syndrome)
- cerebral angiography
- trauma and surgery
- anticoagulation therapy
- changes in intracranial pressure
As the gland suddenly enlarges it may cause compression of structures adjacent to the sella, and thus elicit a number of signs and symptoms, including 7:
- sudden headache
- loss of visual acuity with a chiasmal field defect
- oculomotor palsies
In addition, the patient may experience a decreased level of consciousness, hypopituitarism, Addisonian crisis 3, and subarachnoid irritation, the latter being secondary to hemorrhage.
General features include enlargement of the pituitary gland, with or without bleeding. Macroscopic hemorrhage is common and occurs in about 85%. It shows peripheral enhancement around a non-enhancing infarcted center. Surrounding edema may be seen in the optic tracts and chiasm.
Routine CT is insensitive to the diagnosis unless frank intracranial hemorrhage is present. The pituitary mass may be evident and may be hyperdense. Fluid-debris levels may also be evident.
MRI typically demonstrates a pituitary region mass.
- T1: variable; in cases with hemorrhagic infarction, it is hyperintense due to blood (see aging blood on MRI)
- T2: variable signal
- T1 C+ (Gd): enhancement variable; usually peripheral and may be difficult to identify due to intrinsic high T1 signal
- DWI: restricted diffusion may be present in solid infarcted components 4
Treatment and prognosis
If prompt neurosurgical intervention with the transsphenoidal approach is available to decompress the gland, prognosis is good. Without surgery, the majority of the patients perish. Conservative management may be chosen in selected cases. Pituitary apoplexy is usually associated with irreversible hypopituitarism and often ophthalmoplegia and visual loss 5.
The differential is broadly that of a pituitary region mass, but as these patients present acutely with acute or subacute blood products, it can usually be limited to pituitary region masses with intrinsic high T1 signal.
- necrotic/hemorrhagic pituitary macroadenoma
- appearances are the same, but patients do not present acutely
- whether or not the term apoplexy can be used in subacute presentations is debatable
craniopharyngioma (adamantinomatous type)
- calcification in 90%
- usually in children
- usually not acute presentation
Rathke cleft cyst
- usually asymptomatic
- no associated mass
- usually have a fat component
- unless ruptured, the presentation is usually insidious
- if ruptured, locules of fat density/intensity material are often seen in the subarachnoid space
- 1. Ostrov SG, Quencer RM, Hoffman JC et-al. Hemorrhage within pituitary adenomas: how often associated with pituitary apoplexy syndrome? AJR Am J Roentgenol. 1989;153 (1): 153-60. AJR Am J Roentgenol (abstract) - Pubmed citation
- 2. Kim JP, Park BJ, Kim SB et-al. Pituitary Apoplexy due to Pituitary Adenoma Infarction. J Korean Neurosurg Soc. 2008;43 (5): 246-9. doi:10.3340/jkns.2008.43.5.246 - Free text at pubmed - Pubmed citation
- 3. Mattke AF, Vender JR, Anstadt MR. Pituitary apoplexy presenting as Addisonian crisis after coronary artery bypass grafting. Tex Heart Inst J. 2002;29 (3): 193-9. Tex Heart Inst J (abstract) - Free text at pubmed - Pubmed citation
- 4. Rogg JM, Tung GA, Anderson G et-al. Pituitary apoplexy: early detection with diffusion-weighted MR imaging. AJNR Am J Neuroradiol. 2002;23 (7): 1240-5. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 5. Loftus CM. Neurosurgical emergencies. Thieme Publishing Group. (2008) ISBN:3131350520. Read it at Google Books - Find it at Amazon
- 6. Lazaro CM, Guo WY, Sami M et-al. Haemorrhagic pituitary tumours. Neuroradiology. 1994;36 (2): 111-4. - Pubmed citation
- 7. Rogg JM, Tung GA, Anderson G et-al. Pituitary apoplexy: early detection with diffusion-weighted MR imaging. AJNR Am J Neuroradiol. 2002;23 (7): 1240-5. AJNR Am J Neuroradiol (full text) - Pubmed citation