Endocrine Abstracts

Introduction: Tumour metastasis to pituitary gland is very rare and constitutes only 1% of all pituitary lesions. Breast and lung cancer are the most common neoplasms reported to metastasize to pituitary gland. Most of the pituitary metastasis are asymptomatic, and thus can be easily overlooked in imaging studies. Polyuria and polydipsia due to diabetes insipidus are the most common sypmtoms in these patients. Patients may also present with visual impairment and symptoms of panhypopituitarism. Here, we present a case of endometrial carcinoma with pituitary metastasis.

Case: 71-year-old female presented with a one-week history of loss of apetite and nausea. When questioned, she also reported headache and mild polyuria. One week before admission, she developed gradual right palpebral ptosis, diplopia, and progressive deterioration of vision. Her initial cranial MRI revealed 17 × 17 mm contrast-enhanced sellar tumor and brain edema. The main differential diagnosis of the sellar mass was pituitary metastasis of malignancy. The patient admitted initially to Neurology Department. On admission, her physical examination was normal except for the low blood pressure and right palpebral ptosis. Her ophtalmologic examination confirmed third nerve palsy. She had a history of endometrial serous carcinoma diagnosed in 2017, and she had undergone total histerectomy,bilateralsalpingo-oophorectomy, bilateral pelvicand para-aorticlymph nodedissection and omentectomy. After six cycles of paclitaxel-carboplatin, 18F-fluorodeoxyglucose (FDG) positron emission tomographic/computed tomographic (PET/CT)revealed liver and bone metastasis. She received six cycles of bevacizumab and doxorubicin, and she was on remission until her follow-up visit in June 2019. Routine laboratory evaluation showed a mild hypernatremia (Na = 151 mEq/l) and low urine density (1005). Initial pituitary hormonal assessment demonstrated panhypopituitarism. Hypernatremia, low urine density and osmolality were compatible with diabetes insipidus. She was immediately treated with steroids, levothyroxine and desmopressin after the diagnosis. In subsequent days, her sodium levels were back to normal and urine output decreased. An 18F-FDG-PET-CT confirmed pituitary metastasis. Unfortunately, the patient was lost a week later due to extensive tumor burden. An autopsy was not performed.

Discussion: In conclusion, we present a case with sellar mass,ophthalmoplegia, headaches, hypopituitarism, mild diabetes insipidus, and known history of malignancy; imaging studies revealed pituitary metastasis. To the best of our knowledge, this is the second case of pituitary metastasis of endometrial carcinoma. Sudden onset of diabetes insipidus and ophtalmoplegia in a patient with known history of malignancy should raise the suspicion of pituitary metastasis.