Sunday, 8 July 2018

Pituitary stone

Clinically a known case of pituitary macro adenoma, prolactinoma as lab reports were showing high levels of prolactin. Under regular treatment of Bromocriptine.
CT SAG REFORMATTED IMAGE
CT SAG REFORMATTED IMAGE
MRI BRAIN SAGITTAL T2W IMAGE
Pituitary stone

Also known as pituitary lithiases or pituitary calculus.
A very rare entities defined as extensive calcifcation in the sella turcica.

There is inconsistency regarding what pituitary stones actually are. Some authors suggest the term be used only for calcifications in the sella turcica that occur in the absence of any other pituitary pathology, others use this term more liberally to describe excessive calcification from any cause, such as pituitary adenoma.

Epidemiology
Although the exact incidence is unknown, this entity is generally considered to be very rare as there are only 1 to 6 case reports of idiopathic calcifications so far. However, calcification in pituitary adenoma is considered more common which is approximately 10%.

The aetiology of 'primary' de-novo pituitary stones remains an enigma but is thought to be secondary to an unknown inflammatory process, subclinical haemorrhage, or cartilaginous metaplasia.
In cases secondary to other pathologies, most commonly pituitary adenomas, especially in prolactinomas, is thought to be a sequelae of fibrosis secondary to haemorrhage.

Other secondary causes rare and include Pituitary tuberculosis, metabolic imbalances like hypercalcaemia, sequel of pituitary apoplexy.

Clinical presentation varies significantly, may be entirely asymptomatic or endocrinopathies such as hypopituitarism, hyperprolactinaemia from an underlying pituitary adenoma or hemorrahge.

Imaging
CT is the modality of choice, best demonstrated on sagittal reformatted images as in this case, where they appear as well defined hyperdense nodule in the sella turcica. On MRI, signal changes are consistent with calcification that is low signal on T1, T2 as well as GRE without enhancement on post contrast.

Treatment and prognosis
Presence of stone in a macro adenoma not going to change line of management, treatment should be directed towards underlying cause. It should be left alone if idiopathic and asymptomatic.

Differential diagnosis off course in absence of macroadenoma should include calcified Rathke cleft cyst, calcified meningioma and calcified aneurysm in pituitary region. 

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