Approach to the Patient: A Case With an Unusual Cause of Hypopituitarism

Hypopituitarism, which refers to insufficiency of one or more hormones of the pituitary, can be due to myriad causes. The clinical and radiological spectrum of the condition is heterogeneous, based on the patient's age, gender, clinical setting, and/or other past medical history. Hypopituitarism includes central hypocortisolism, hypothyroidism, hypogonadism, and growth hormone deficiency. Both hypo- and hyperprolactinemia can be associated with hypopituitarism, with low prolactin signifying more extensive pituitary damage. Posterior pituitary insufficiency (arginine vasopressin deficiency) occurs either in isolation or with anterior pituitary hormone deficiency. Clinical symptomatology of hypopituitarism is usually nonspecific and insidious in onset and progression. Overall, the most common cause of hypopituitarism is a pituitary adenoma and/or its management (surgery, radiotherapy, pharmacotherapy, or a combination of these). However, it is this subset of patients which is more likely to be identified and managed in a timely manner, possibly alleviating the premature mortality associated with hypopituitarism. What is more challenging is the recognition of hypopituitarism in less common settings, which may be either due to direct involvement of the pituitary (infection, traumatic brain injury, or infiltrative causes) or indirectly as a consequence of the primary process (thalassemia, vasculotoxic snakebite, subarachnoid hemorrhage). These entities are often under-recognized, and increased awareness can help in greater recognition of the burden. Further, pituitary insufficiency in most of these settings is dynamic and may progress, or rarely, show recovery of function. This renders complexity to the problem, but makes it even more imperative to suspect, screen, and appropriately manage patients with less common causes of hypopituitarism.