Prolactinoma

Patient Presentation:
H.M., a 33-year-old female presents to the OB/GYN office complaining of amenorrhea and nipple discharge. Patient reports that she has been trying to get pregnant for the past 8 months so when she missed her period 5 months ago, she assumed she was pregnant; however, she reports that she has taken multiple pregnancy tests since her last menstrual period, all producing negative results. Patient reports having a normal 28-day menstrual cycle starting when she was 13-years-old with 5 day periods and mild cramping, headaches and breast soreness before each menses. Patient reports having her last regular menstrual period 5 months ago with no noted abnormalities. She reports that she has never been pregnant before and has taken oral contraceptives since she became sexually active up until 8 months ago when she and her husband began trying to get pregnant; and therefore, she is unaware of any underlying fertility issues. Patient describes nipple discharge as “white discharge that leaks from the breast randomly every day”. Patient denies any pain, swelling, tenderness or redness on nipples. Patient reports a decreased libido and vaginal dryness with intercourse and denies any other sexual dysfunction. Patient denies any other health changes, including regular headaches, weight changes, fatigue, depression, visual changes and/or changes in facial bone structure. Past medical history is insignificant and family history is significant only for colon cancer in two second degree paternal relatives. Physical exam reveals normal pelvic and genital development with Tanner Stage 5 breast development and Tanner stage 6 pubic hair development. Breasts are non-tender with no redness or swelling around nipples. Small amount of white, milky discharge is noted around nipples bilaterally. Palpation and stimulation of breasts elicited additional discharge secretion. Physical exam also revealed thin, dark hair on face in male distribution pattern, which patient described to be a recent development. Remainder of physical exam is benign. Patient denies use of any medications.

Differential List:
Prolactinoma presenting with galactorrhea and amenorrhea is the likely diagnosis due to history and physical exam findings. However, laboratory data and MRI imaging will be necessary for diagnosis. Other causes of hyperprolactinemia must be investigated before a diagnosis of prolactinoma can be confirmed. Renal failure, for instance, can elevate prolactin levels and, therefore, must be ruled out before diagnosis.

Diagnosis:
Laboratory tests reveal: negative pregnancy test; elevated prolactin (250 ng/ml); low FSH and LH levels due to suppression of GnRH; normal kidney function; normal thyroid function; normal liver function.  Radiology tests: MRI with contrast of the sella turcica reveals a pituitary microadenoma (estimated size is 6 mm in diameter).  The diagnosis is prolactinoma.

Treatment:
Asymptomatic microadenomas usually do not require treatment; however, in cases with problematic infertility and/or galactorrhea, patients are treated with dopaminergics, such as bromocriptine or cabergoline. In normal circumstances, the hypothalamus secretes dopamine, which acts as the prolactin inhibiting factor. Thus, dopaminergic medications, such as bromocriptine will treat hyperprolactinemia by providing prolactin’s inhibiting-factor. The use of these medications is associated with rapid reduction in tumor size and restoration of fertility. In this case, the patient receives bromocriptine. Within six months of initiating treatment, the patient begins to ovulate again with regular menstrual cycles and milk production ceases.

Outcome:
Goals for treatment of prolactinoma include controlling prolactin levels, maintaining normal gonadal function and cessation of galactorrhea. In this case, the goals for treatment were achieved within 6 months of treatment initiation. Therefore, this patient will continue medication under close medical attention. If the patient becomes pregnant, patient will need to consult with her OB/GYN closely in order to evaluate treatment options for during pregnancy and the post partum period. The OB/GYN may consider taking patient off of the medication in order to decrease fetal exposure; however, if the prolactinoma is large and/or causes severe symptoms, patient may continue with medication throughout pregnancy.  Infrequently, patients stop medicine after prolactin levels and gonadal function remain stable for a specified amount of time; however, with medication cessation, tumor re-growth is very likely. In more severe cases of prolactinoma, the tumor can grow to be so large that it interferes with vision by compressing on the optic chiasm. In such severe cases, surgical treatment in considered after medication is not successful.
Case created by Hannah MacIntyre, 2011.