Craniopharyngioma

What it is

Craniopharyngioma is a low-grade malignancy derived from remnants of Rathke pouch.

How it presents

Two compressions give it its picture. Optic chiasm compression gives bitemporal hemianopsia. Pituitary stalk compression gives endocrinopathies, for example growth hormone deficiency and diabetes insipidus.

That second route is why it appears again among the causes of primary amenorrhea. There it sits under pituitary dysfunction with low FSH and LH, that is hypogonadotropic hypogonadism with low estrogen, so the secondary sexual characters are absent: underdeveloped breasts and absent axillary and pubic hair.