Endocrine Abstracts

Introduction: A biochemical profile of an underactive pituitary gland allied to visual field loss is commonly due to an underlying adenoma. We report a case where such a clinical picture was found but imaging/biopsy revealed a different cause.

Case report: A 52-year-old Indian male was referred by his GP to an endocrine outpatient department with reduced visual acuity, balance problems and a biochemical profile of an underactive pituitary gland. Past history included hyperlipidaemia, allergic rhinitis and depression. Examination revealed a bitemporal hemianopia but no long tract neurological signs. Blood tests showed free T₄ of 6 pmol/l, TSH 0.26 ml/l, testosterone nul <0.1 ng/ml, prolactin 885 μ/l and IGF1 6.0 nmol/l. An MRI head showed a large ill-defined mass of the optic chiasm. This extended into the hypothalamus and was suspicious of an optic chiasm glioma. The patient was started on thyroxine, testosterone and hydrocortisone therapy. He was referred for neurosurgical opinion and a hypothalamus biopsy revealed the presence of granuloma. Cerebrospinal fluid culture is currently negative for TB but showed a raised protein level of 0.98 g/l. The patient was started on anti-TB medication (he had reported contact with a family member who had TB) and steroids (for the possible differential of sarcoid.) This patient continues to be cared for by the endocrinology, neurology, ophthalmology and respiratory teams.

Discussion: Visual field loss alongside a picture of an underactive pituitary gland is not always caused by an adenoma. In such cases where other causes are apparent, medical replacement therapy is merited alongside involvement of different specialists in the long-term management plan.