Detection of a microgonadotropinoma by magnetic resonance imaging performed because of excellent response to controlled ovarian hyperstimulation despite elevated day 3 FSH.

PURPOSE: To determine if a better response than anticipated to controlled ovarian stimulation in a woman assumed to have diminished oocyte reserve based on an increased day 3 serum follicle stimulating hormone (FSH) level, could be related to a gonadotropinoma.

MATERIALS AND METHODS: Magnetic resonance imaging (MRI) with and without gadolinium contrast was used in a woman who made 21 mature oocytes despite a history of day 3 serum FSH as high as 20 mIU/mL.

RESULTS: A pituitary microgonadotropinoma was detected.

CONCLUSIONS: The presence of a better response than anticipated to controlled ovarian hyperstimulation (COH) with exogenous gonadotropins despite an increase in day 3 serum FSH should prompt a search for a possible gonadotropinoma.