Management of a mixed ACTH- and prolactin-secreting pituitary adenoma during pregnancy

The diagnosis and management of Cushing's disease (CD) during pregnancy are challenging. Only a few cases of mixed pituitary adenomas secreting prolactin and ACTH have been reported, and none during pregnancy. We report the case of a 30-year-old woman who presented with galactorrhea, weight gain, hypertension, prediabetes, dorsal fat pad, and abdominal striae. Initial biochemical investigations revealed hyperprolactinemia with increased ACTH but no biochemical signs of hypercortisolism. Pituitary MRI showed a 10 mm pituitary adenoma, which was first considered a prolactinoma potentially co-secreting ACTH. Surgery was indicated, but the patient did not undergo treatment immediately due to lack of health insurance. Cabergoline monotherapy was initiated, with close follow-up advised until regularization of social status in Belgium. The patient was then lost to follow-up and presented 15 months later because of an early pregnancy with treatment-resistant hypertension. Biochemical evaluation during the first trimester led to the suspicion of ACTH-dependent cortisol excess and showed hyperprolactinemia despite ongoing cabergoline treatment. She underwent transsphenoidal surgery at 16 weeks of pregnancy, and pathological examination showed a single adenoma with two different cell components staining for PRL/PIT1 and ACTH/TPIT, respectively. Surgery was successful, the patient developed corticotrope insufficiency, and was able to stop antihypertensive drugs. Because of failed induction of labor (for gestational insulin-requiring diabetes), she underwent cesarean section at 39 weeks of pregnancy and gave birth to a healthy boy with no maternal or neonatal complications. Adrenal insufficiency recovered 12 months after surgery. Genetic testing for MEN1 and AIP was negative.

Mixed ACTH- and PRL-secreting pituitary adenomas, although extremely rare, do occur and may lead to both Cushing's syndrome and galactorrhea/oligo- or amenorrhea syndrome. Cabergoline therapy is an option in such cases and may decrease both PRL and ACTH levels; however, its efficacy in controlling Cushing's disease is limited. Preconception counseling is essential in women of childbearing age suffering from secreting pituitary tumors. Management of prolactinoma during pregnancy usually includes cessation of dopamine agonists and close follow-up to detect tumor growth, especially during the third trimester. Diagnosis of Cushing's syndrome during pregnancy is challenging due to the physiological activation of the hypothalamic-pituitary-adrenal axis. Cushing's syndrome may worsen during pregnancy and is associated with severe maternal and fetal complications. Early diagnosis and treatment are essential to improve fetomaternal outcomes. Transsphenoidal surgery performed during the second trimester is an effective and safe treatment for ACTH-secreting adenomas during pregnancy.