Pituitary tumors

• Anterior Lobe (adenohypophysis) - T1 dark, produces ACTH, TSH, GH, prolactin, LH, FSH, endorphin and intermedins
• Posterior Lobe (neurohypophysis) - T1 bright, stores oxytocin and ADH
• Pars Intermedia - inbetween anterior and posterior
• Stalk - connects to hypothalamus

Masses

Rathke Cleft Cyst

• Midline at pars intermedia
• Variable T1 and T2 signal due to proteinacious material
• No enhancment

Adenoma

• Arises from anterior lobe
• Less than 1 cm is microadenoma, Grearter than 1 cm is macroadenoma
• May be functional
• Important to identify invasion of cavernous sinus
• Macroadenomas have a figure of 8 appearance and can cause bitemporal hemianopsia

Pituitary Apoplexy - Hemorrhage resulting in sudden onset of headache usually associated with visual disturbance

Differential

• Craniopharingioma - suprasellar
• Meningioma - narrows ICA
• Sarcoidosis - typically involving the stalk
• Hypophysitis
• LCH
• Metastasis
• Hypothalamic hamartoma - gelastic seizures
• Optic glioma
• Chondrosarcoma
• Germinoma

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Chapter 4 - Radiology of the Pituitary Jane Evanson, MD, Consultant neuroradiologist Barts and the London NHS trust.