Mucocele-like formation leading to neurological symptoms in prolactin-secreting pituitary adenomas under dopamine agonist therapy

Abstract

BACKGROUND Mucocele-like formation associated with pituitary adenomas, to the best of our knowledge, has been paid little attention. We report three adult male patients with a mucocele-like formation that developed behind the tumor and led to neurological symptoms in prolactin-secreting pituitary adenomas (prolactinomas) under dopamine agonist therapy. CLINICAL PRESENTATION Three adult male patients with prolactinomas developed hyperprolactinemia and new neurological symptoms during dopamine agonist treatment. In each case, the pathogenesis of these symptoms was due in part to a mass enlargement with development of a mucocele-like formation behind a prolactinoma. In our patients, a prolactinoma with a suprasellar extension originally filled the sphenoid sinus. When dopamine agonist therapy became ineffective, new symptoms, such as progressive visual impairment other than typical hemianopsia or headache, developed and mass enlargement was found on MRI. MRI demonstrated two different components: an enhancing prolactinoma and a nonenhancing mucocele-like formation behind the tumor. Two patients had compression of the optic nerves by a mass. Transnasal removal of mucoceles and adenomas led to resolution of the neurological symptoms. CONCLUSION Early suspicion of a mucocele-like formation under dopamine agonist therapy for prolactinomas is important in order to avoid a delay in surgery, because a change in medical treatment will be ineffective.