Endocrine Abstracts

Background: Pituitary gland metastasis is rarely the initial presentation of metastatic cancer. Most cases of pituitary gland metastasis are asymptomatic with diabetes insipidus being the most common symptomatic presentation. It can rarely present with symptoms of hormone underproduction such as anterior pituitary deficiency. Although pituitary gland metastasis is rare, it is underestimated, as it is commonly misdiagnosed with pituitary gland adenoma due to the lack of clear radiological criteria differentiating between both.

Case report: We present a case of a 63-year-old male known as small cell lung cancer owner for already two years, under chemotherapy and mediastinal radiotherapy. The brain scanner initially done as assessment of extension didn’t show any anomaly as for the rest computed tomography scan; however four months later; the patient presented blurry vision and persistent headache. This was followed by a brain magnetic resonance imaging (MRI), which showed one unique lesion with an enhancing mass 40 mm long axis involving the right clivus, intrasellar and suprasellar cistern with mass effect on the optic chiasm and involvement of the cavernous sinus and the internal carotid artery; this was supporting both diagnosis of pituitary’s macroadenoma and pituitary gland metastasis of small cell lung cancer. Further workup showed no sign of hypersecretion; but conversely showed evidence of hypopituitarism like corticotroph deficiency with (morning cortisol level 36 nmol/l ), thyreotropic deficiency TSH (0.062 uUI/ml) FT4 (10.19 pmol/l), gonadotropic deficiency FSH (0.403 mUI/ml) and LH (<0.100 mUI/ml) and disconnection hyperprolactinemia PRL (32 ng/ml), however there wasn’t any sign of diabetes insipidus.

Conclusion: The majority of pituitary gland metastasis cases presenting with hypopituitarism have lung cancer as their primary tumor. Many cases of pituitary gland metastasis have been misdiagnosed as pituitary adenomas due to the lack of clear radiological findings that differentiate between these two conditions. However, it is important for physicians to be familiar with the radiological findings and presentations that could favor one diagnosis over the other.