Giant Prolactinoma Presenting With Facial Nerve Palsy and Hemiparesis

Aleksandra Sliwinska; Fatima Jalil; Lori De La Portilla; Michael Baldwin; Joseph Lorenzo; Ketan R. Bulsara; Faryal S. Mirza


J Endo Soc. 2021;5(9) 

In This Article

Abstract and Introduction


Background: Giant prolactinomas are an exceedingly uncommon type of pituitary adenomas that usually occur in men, and cause extremely high prolactin levels and mass-related symptoms. Rarely, patients may experience neurological deficits resembling ischemic events.

Methods: We describe an unusual case of a young man who presented with stroke-like symptoms and was found to have a giant prolactinoma.

Clinical Case: A 25-year-old man presented with left facial droop and gradually progressing upper and lower extremity weakness for evaluation of stroke. He reported recent weight gain and erectile dysfunction. Physical examination revealed left homonymous hemianopsia, left VII nerve palsy, and left hemiparesis. Magnetic resonance imaging of the brain showed an enormous mass in the sella turcica, which invaded the sphenoid sinus and right side of the skull base. Prolactin level was elevated at 13 580 ng/mL, and the testosterone level was low. The patient was started on cabergoline and had marked improvement in his symptoms in a few months. Fifteen months after starting treatment, he has had more than 90% reduction in tumor volume and a 93% reduction in prolactin level.

Conclusion: Giant prolactinomas are uncommon and present with compressive symptoms that can be mistaken for a stroke. Our case is a unique report of a facial nerve palsy and hemiparesis secondary to giant prolactinoma in the absence of stroke or pituitary apoplexy.


Lactotroph adenomas are the most common pituitary adenomas and can cause infertility and menstrual irregularities in women, and hypogonadism and gynecomastia in men.[1–3] Most prolactinomas are described as microadenomas with a diameter of less than 10 mm and are more prevalent in women.[1] Giant prolactinomas (GPs) are a subset of pituitary macroadenomas with limited literature on their management. GPs occur more commonly in men, and, by definition, grow to more than 4 cm in diameter and produce prolactin (PRL) levels above 1000 ng/mL.[4]

Symptoms from GPs are usually due to mass effect on surrounding tissue and significant elevation in PRL, causing hypogonadotropic hypogonadism. Dopamine agonists (bromocriptine and cabergoline [CAB]) are considered first-line therapy in GP treatment; however, a surgical approach may be necessary if the tumor continues to cause mass effect and impending visual threat.[5,6] Although palsies of cranial nerves III-VI have been reported, facial nerve palsy and hemiparesis are relatively unique presentations.[4]

We describe an unusual case of a young man who presented with symptoms of motor weakness in the upper and lower extremities with concern for stroke, who on evaluation was noted to have a large multilobular mass in the region of the right cavernous sinus. He was subsequently diagnosed with a giant prolactinoma based on an elevated PRL level. He was started on medical therapy with CAB with complete resolution of the motor deficits over the next few months.