What does this 17-year-old’s brain tell us about why she stopped menstruating?

This 17-year-old female presents with secondary amenorrhea. You are shown two sagittal and three coronal images. What are the causes of pituitary gland enlargement other than a tumor? Which tumor causes infertility and dysmenorrhea or galactorrhea? Could this pituitary hypertrophy be in any way related to amenorrhea? What does the arrow on image 5 indicate?

Sagittal T1

Sagittal T1

Coronal T1

Coronal T2

Coronal T1

Pituitary enlargement with heights of 12-14 mm can occur during the normal pubertal period, and can also occur during pregnancy and/or lactation. These are by far the most common causes of pituitary enlargement or hypertrophy.

Other important causes of pituitary hypertrophy include anorexia nervosa, hypothyroidism and any end organ failure. In fact, end organ failure at the endocrine axis in the pelvis, including ovarian failure, may lead the gland to hypersecrete LH and FSH to compensate and result in pituitary hypertrophy, though this is a rare event.

Pituitary microadenomas with prolactin secretion can cause infertility. No such lesion is present here. In fact, the pituitary vasc plexus or “tuft” is midline. Localizing the midline position of this tuft can be invaluable in assessing whether a true pituitary microadenoma a millimeter or two in size is present. If present, the tuft will be displaced.¬†The green arrow on image 5 is a sign of the absence of intrasellar mass effect. For more case review, head to MRI Online.

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