Endocrine Abstracts

Background: Patients with macroprolactinoma commonly manifest with symptoms attributable to hyperprolactinemia and/or mass effect. Seizures are a rare presenting feature. We report a case of a male patient who presented with seizures and was subsequently diagnosed with cystic prolactinoma, with favourable response to dopamine agonist therapy.

Case description: A 29-year-old man initially presented with generalized tonic-clonic seizures. MRI brain revealed a 5.7x2.4x2.1 cm pituitary macroadenoma with suprasellar extension and cystic degeneration, without any evidence of hydrocephalus. Visual field assessment showed bitemporal hemianopia. Hormonal evaluation indicated a significantly elevated prolactin level of over 42,000 mIU/l, along with secondary hypogonadism. Cabergoline and Levetiracetam were initiated, resulting in notable clinical, biochemical improvement and near-complete radiological resolution; however, he was subsequently lost to follow-up. He presented again with similar seizure episodes five years after the initial presentation. Investigations revealed a recurrence of the partially cystic pituitary adenoma measuring 5.4x2.4x2.1 cm, with bitemporal hemianopia and prolactin levels of 84,821 mIU/l. The patient was treated mirroring the initial approach, supported by family involvement ensuring compliance. He exhibited a favourable response with respect to both his prolactin levels and visual symptoms. A follow-up MRI after six months of treatment showed significant tumour regression with residual changes, and the patient has remained free of seizures.

Conclusion: In the context of macroprolactinomas, seizures are occasionally observed as a complication of medical management, typically due to hemosiderin deposition in the medial temporal lobe following intra-tumoural haemorrhage. However, seizures as an initial presentation in patients with macroprolactinoma are rare. Our patient presented with seizures on both occasions, which were attributed to the large prolactinoma. Medical management, including dopamine agonists, remains the primary treatment approach, often resulting in documented tumour regression and subsequent reduction in seizure frequency, allowing for the gradual tapering and cessation of anti-epileptic treatment.