Pituitary Origin of Persistently Elevated Human Chorionic Gonadotropin in a Patient with Gonadal Failure

Capsule:
Pituitary hCG should be considered in the differential diagnosis of persistently elevated hCG levels in young patients with gonadal failure when the more common and more ominous causes have been excluded.

Authors:
Zaher Merhi, M.D., Staci E. Pollack, M.D.

Volume 99, Issue 1, Pages 293-296, January 2013

Abstract:

Objective:
To report a case of persistently elevated low levels of hCG to increase awareness of pituitary origin of persistently elevated hCG in patients with gonadal failure.

Design:
Case report and literature review.

Setting:
Large university-affiliated infertility practice.

Patient(s):
A 16-year-old patient with primary amenorrhea, normal secondary sex characteristics, ovarian failure, and a 46,XY karyotype. Her past medical history was significant for focal segmental glomerulosclerosis, leading to a diagnosis of Frasier syndrome.

Intervention(s):
At age 31 years, she desired pregnancy by oocyte donation and was found to have persistently elevated low levels of hCG (>35 mIU/mL).

Main Outcome Measure(s):
Pituitary hCG.

Result(s):
Both serum free β-hCG and hyperglycosylated hCG were undetectable. Total serum hCG diluted appropriately was not blocked by blocking agent and was detected in the urine. Subsequent treatment with exogenous E2, in preparation of a donor oocyte cycle, suppressed her hCG levels (down to 8 mIU/mL). These results indicated a pituitary source of the serum hCG.

Conclusion(s):
This report reinforces the need to consider pituitary hCG as the origin of persistently elevated hCG levels in patients with gonadal failure. Although levels of hCG <14 mIU/mL have been considered normal in postmenopausal women, our case suggests that patients with gonadal failure at younger ages might have a higher pituitary output of hCG.

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