Endocrine Abstracts

The most common cause of hyperprolactinemia is a prolactinoma in women after pregnancy is excluded. A 34-year-old female presented to our clinic with a 1.5 year history of secondary amenorrhea, galactorrhea and malaise. Prolactin (PRL) level was found to be 151.89 ng/ml. Pituitary imaging was reported to be normal. An examination of the patient revealed that PRL level was still high so the dose of cabergoline was further increased and subsequently, bromocriptine was added to the treatment. There was no reduction in PRL levels in controls. A scanning was performed to look for an ectopic focus. Abdominal computerized tomography revealed a heterogenous mass lesion originating from the uterus. Octreotide scintigraphy was performed and we observed an involvement consistent with the mass in the uterus. The patient underwent abdominal total hysterectomy. PRL dropped to 0.4 ng/ml the next day after the operation. The pathology result was a low-grade malignant mesenchymal tumor. Prolactin was found to be immunohistochemically negative. However, galactorrhea disappeared postoperative and PRL levels are still low. Elevated levels of PRL, resistant to bromocriptine and cabergoline, rapidly returned to normal after hysterectomy, which obviously indicates that hyperprolactinemia was associated with the myoma of the uterus. Other than pituitary PRL secretion, ectopic hyperprolactinemia may be caused by the presence of a pituitary tissue in the ectopic focus or, as in our case, secretion of dopamine antagonist or PRL stimulating factors from the tumor tissue, which is unable to detect.