Abstract
Prolactinomas are the most common form of endocrinologically active pituitary adenoma;
they account for ∼ 45% of pituitary adenomas encountered in clinical practice. Giant
adenomas are those > 4 cm in diameter. Less than 0.5% of pituitary adenomas encountered
in neurosurgical practice are giant prolactinomas. Patients with giant prolactinomas
typically present with highly elevated prolactin levels, endocrinologic disturbances,
and neurologic symptoms from mass-induced pressure. Described here is an unusual case
of a giant prolactinoma presenting with neck pain and structural compromise of the
occipital condyles. Transnasal biopsy of the nasopharyngeal portion of the mass obtained
tissue consistent with an atypical prolactinoma with p53 reactivity and a high Ki-67
index of 5%. Despite the size and invasiveness of the tumor, the patient had resolution
of his clinical symptoms, dramatic reduction of his hyperprolactinemia, and near-complete
disappearance of his tumor following medical treatment.
Keywords
pituitary adenoma - giant prolactinoma - occipitocervical instability - occipital
condyles - invasive adenoma
