Plasma melatonin, luteinizing hormone, follicle-stimulating hormone, prolactin, and corticoids in two patients with pinealoma.

Plasma melatonin, LH, FSH, PRL, and corticoids were measured in two patients with pineal tumors. Plasma melatonin was not detectable (less than 7 pg/ml) in either patient while gonadotropin and cortisol levels were within the normal range. One patient exhibited low PRL levels and the other patient, a prepubertal boy, had elevated levels. The clinical value of the measurement of melatonin as a potential marker for all pineal tumors must be questioned.