Pituitary hyperplasia refers to the diffuse pituitary enlargement that can be physiologic in young menstruating females or pregnant/lactating women or, less commonly, secondary to end-organ failure.
Upper limit of normal pituitary height varies with age and gender:1
- infants, children: 6mm
- males and postmenopausal women: 8mm
- young menstruating females: 10mm
- pregnant/lactating women: 12mm
Nonphysiologic pituitary hyperplasia is commonly caused by an end-organ failure such as hypothyroidism, Addison disease3 and neuroendocrine tumors4. Medications such as oestrogen, GNRH analogues and and antipsychotics can cause or exacerebrate pituitary hyperplasia4.
The pituitary gland can be assessed both by CT and MRI dedicated protocols, which can show:1
- enlarged homogeneously enhancing pituitary gland with a convex superior margin
- size : > 10mm up to 15 mm
- may be globular / nodular, mimicking pituitary adenoma
Treatment and prognosis
Only surveillance is suggested till reversal of the underlying pathological condition as pituitary hyperplasia rarely progresses4.
- 1. Osborn AG, Salzman KL, Barkovich AJ. Diagnostic Imaging. Lippincott Williams & Wilkins. (2009) ISBN:1931884722. Read it at Google Books - Find it at Amazon
- 2. Elster AD, Sanders TG, Vines FS et-al. Size and shape of the pituitary gland during pregnancy and post partum: measurement with MR imaging. Radiology. 1991;181 (2): 531-5. doi:10.1148/radiology.181.2.1924800 - Pubmed citation
- 3. Agrawal A, Diwan SK. Pituitary hyperplasia resulting from primary hypothyroidism. Asian J Neurosurg. 2011;6 (2): 99-100. doi:10.4103/1793-5482.92171 - Free text at pubmed - Pubmed citation
- 4. De Sousa SM, Earls P, McCormack AI. Pituitary hyperplasia: case series and literature review of an under-recognised and heterogeneous condition. Endocrinology, diabetes & metabolism case reports. 2015: 150017. doi:10.1530/EDM-15-0017 - Pubmed