Endocrine Abstracts

Introduction: Pituitary metastases (PM) are an uncommon manifestation of Neuroendocrine neoplasms (NENs) and are rarely reported. We report two cases of PM with different clinical lessons.

Case 1: A 37-year-old female underwent surgical resection for a high grade poorly differentiated neuroendocrine carcinoma of the cervix (Ki67 90%). Serial follow-up surveillance assessments revealed disease progression (local, liver, lung, and bone) for which she underwent different oncological therapies including chemo-, immuno- and radiotherapy. However, 4 years from initial diagnosis, she presented with frontal headaches and peripheral visual disturbance. MRI brain imaging revealed a 3 cm lesion within the pituitary Sella with suprasellar extension suggestive of pituitary metastasis. Treatment with dexamethasone led to symptomatic relief. Biochemistry was suggestive of secondary hypothyroidism (TSH 0.1 mU/l [0.55–4.78]; free T4 10 pmol/l [10–22]) and hypogonadotrophic hypogonadism (LH <1 mu/l; FSH 3 mU/l; oestradiol <70 pmol/l). Her pituitary lesion showed a marked reduction in size with the addition of carboplatin/paclitaxel (from 3 cm to 0.8 cm). Due to tumour size reduction and patient wishes, surgery was withheld. She was subsequently treated with external beam radiotherapy.

Case 2: A 64-year-old female diagnosed with a T2a N2 M0 lung NEN for which she underwent primary surgical resection (histology: well-differentiated grade 3 NEN [Ki67=25%]) with satisfactory postoperative cross-sectional and functional imaging. Within 12 months surveillance imaging showed bone metastases and she was commenced on lanreotide, Denosumab and external beam radiotherapy. Three months later she presented with headaches and visual disturbance; MRI brain showed 0.7 cm hypointense lesion on the pituitary gland. She was biochemically eupituitary and suspected to have an incidental pituitary adenoma. Surveillance imaging (4 months later) showed progressive increase in the size of the pituitary lesion (11 mm). Clinical symptoms and pituitary function tests revealed panhypopituitarism and DI (cortisol 84 nmol/l, ACTH <5 ng/l, TSH <0.02 mU/l, free T4 11.6 pmol/l, FSH 1 IU/l, LH 1 IU/l, serum osmolality 296 mOsm/kg [275–295], urine osmolality 87 mOsm/kg [>100], sodium 147 mmol/l [133–146], IGF-1 22 ng/ml [39–165]). She was treated with hydrocortisone, levothyroxine, and desmopressin. She underwent debulking surgery after multidisciplinary team discussion and post-operative histology was in keeping with a metastatic lung NEN. She is receiving postoperative radiotherapy.

Discussion: Pituitary metastases are rare but important in NENs and should be considered in patients with headaches, visual disturbances or features of hypopituitarism. The multimodal treatment for PM requires multidisciplinary input with individualized options being offered to the patient.