Follicle Stimulating Hormone (FSH) secreting pituitary adenoma causing spontaneous ovarian hyperstimulation syndrome

Objectives: As a spontaneously occurring entity, ovarian hyperstimulation syndrome (OHSS) presents as an atypical and perplexing array of symptoms. It has been described in association with pregnancy in polycystic ovarian disease patients, severe primary hypothyroidism, and granulosa cell tumors. We present a case of spontaneous OHSS resulting from a FSH-secreting pituitary adenoma.Design: Case studyMaterials and Methods: This patient is a previously healthy 29 year old gravida 0 presenting with gradually increasing right-sided adnexal pain, a six month history of increasing abdominal girth, and secondary amenorrhea. Ultrasound examination revealed multiple two to three centimeter ovarian cysts and a bilateral ovarian diameter of approximately 20 cm. A laparotomy was performed and multiple benign follicular cysts excised. Laboratory evaluation showed an FSH of 6.8 mIU/ml, LH of 0.1 mIU/ml, prolactin of 67 ng/ml, progesterone of 3.5 ng/ml, estradiol of 237 pg/mL, and an α-subunit of 1.2 ng/ml. MRI examination of the sella demonstrated a homogeneously enhancing mass measuring 2.0x2.3x1.5 cm within the pituitary, which extended superiorly and impinged on the optic chiasm. Slight deviation of the left internal carotid artery was noted and possible extension to the left cavernous sinus.Results: An uncomplicated transsphenoidal resection of all evident tumor was performed, including a portion of tumor extending into the cavernous sinus. Pathologic description was consistent with a benign pituitary gonadotroph adenoma. Sections revealed sheets of reticulin-free adenomatous tissue, comprised of cells with cytoplasm immunoreacting focally with antibodies against FSH, but not with those against GH, PRL, ACTH, LH, TSH or α-subunit. MRI examination two months after surgery confirmed the absence of tumor within suprasellar and sellar regions, but revealed a small amount of tissue within the cavernous sinus consistent with residual tumor. Her menstrual cycle resumed within 4 months, with laboratory evidence of ovulation.Conclusions: This patient had a FSH level within normal limits, which suggests that the FSH isoform was either biologically more active, or not adequately detected by our assay. Her estradiol level and elevated FSH/LH ratio was consistent with tonic FSH stimulation, and her clinical picture clearly suggested that the pituitary mass was secreting gonadotropins. This case is another example of the conditions’ unusual presentation, and the potential for misdirected management. Our case also outlines the need to view the ovary as a part of the hypothalamic-pituitary-gonadol axis, and not as an organ in isolation. Objectives: As a spontaneously occurring entity, ovarian hyperstimulation syndrome (OHSS) presents as an atypical and perplexing array of symptoms. It has been described in association with pregnancy in polycystic ovarian disease patients, severe primary hypothyroidism, and granulosa cell tumors. We present a case of spontaneous OHSS resulting from a FSH-secreting pituitary adenoma. Design: Case study Materials and Methods: This patient is a previously healthy 29 year old gravida 0 presenting with gradually increasing right-sided adnexal pain, a six month history of increasing abdominal girth, and secondary amenorrhea. Ultrasound examination revealed multiple two to three centimeter ovarian cysts and a bilateral ovarian diameter of approximately 20 cm. A laparotomy was performed and multiple benign follicular cysts excised. Laboratory evaluation showed an FSH of 6.8 mIU/ml, LH of 0.1 mIU/ml, prolactin of 67 ng/ml, progesterone of 3.5 ng/ml, estradiol of 237 pg/mL, and an α-subunit of 1.2 ng/ml. MRI examination of the sella demonstrated a homogeneously enhancing mass measuring 2.0x2.3x1.5 cm within the pituitary, which extended superiorly and impinged on the optic chiasm. Slight deviation of the left internal carotid artery was noted and possible extension to the left cavernous sinus. Results: An uncomplicated transsphenoidal resection of all evident tumor was performed, including a portion of tumor extending into the cavernous sinus. Pathologic description was consistent with a benign pituitary gonadotroph adenoma. Sections revealed sheets of reticulin-free adenomatous tissue, comprised of cells with cytoplasm immunoreacting focally with antibodies against FSH, but not with those against GH, PRL, ACTH, LH, TSH or α-subunit. MRI examination two months after surgery confirmed the absence of tumor within suprasellar and sellar regions, but revealed a small amount of tissue within the cavernous sinus consistent with residual tumor. Her menstrual cycle resumed within 4 months, with laboratory evidence of ovulation. Conclusions: This patient had a FSH level within normal limits, which suggests that the FSH isoform was either biologically more active, or not adequately detected by our assay. Her estradiol level and elevated FSH/LH ratio was consistent with tonic FSH stimulation, and her clinical picture clearly suggested that the pituitary mass was secreting gonadotropins. This case is another example of the conditions’ unusual presentation, and the potential for misdirected management. Our case also outlines the need to view the ovary as a part of the hypothalamic-pituitary-gonadol axis, and not as an organ in isolation.