Category: Reproductive Endocrinology
To report an interesting case of a postmenopausal woman presenting with elevated human chorionic gonadotropin (hCG)
Methods : A 54-year-old woman presents to her gynecologist for colposcopy for an abnormal pap smear. Urine pregnancy test was obtained prior to the procedure which came back positive. Quantitative hCG was then obtained and was elevated at 12 miu/mL. Patient reports that her LMP was not since age 47. Her last sexual intercourse was a year ago. She denies any known pituitary disease or prior malignancy and is otherwise healthy. She denies any tobacco, alcohol or illicit drug use. Biochemical data showed elevated FSH of 212 miu/mL and LH of 138 miu/mL confirming postmenopausal state. Transvaginal ultrasound were obtained with no evidence of discrete nodules or adnexal mass. She was then referred to our clinic for further evaluation.
On further consultation, the patient admitted to chronic marijuana use preceding the abnormal test, but had discontinued since the positive pregnancy test. With the knowledge that marijuana use has been reported to result in a false-positive elevation of beta-hCG, we rehecked patient’s hCG level now that patient had already discontinued marijuana use, and the test came back normal. Patient was then advised that no further endocrine intervention is warranted.
Slightly elevated serum (hCG) can be a normal finding in postmenopausal women. Studies have since demonstrated that hCG production by the pituitary increases in menopause, but the precise mechanism by which such production occurs has not been elucidated. The level of hCG attributable to pituitary production ranges from 1 to 32 mIU/mL. Confirmation of the pituitary as a source of low level hCG can be made by placing the patient on an oral contraceptive pill for three weeks to inhibit release of GnRH and, in turn, pituitary hCG production. If hCG is suppressed after this period of time, then the pituitary gland is the origin of the hCG. False-positive elevation of beta-hCG from Marijuana use can also be seen. Evidence suggests that marijuana can reduce female fertility by disrupting hypothalamic release of GnRH. However, the mechanism behind spurious rise in hCG induced by marijuana remains unclear.
With the prevalence of positive hCG among postmenopausal women of approximately 8%, it is important that physicians are aware of normal pituitary secretion of hCG in postmenopausal women. It is equally important for endocrinologist to be aware of possible spurious elevation of hCG level with marijuana use in postmenopausal women to avoid unnecessary evaluation and clinical confusion.
Assistant Professor of Medicine
Loyola University Medical Center
Clinical Educator at Loyola University Medical Center