You need to put your husband under the care of an endocrinologist who works with or in a pituitary centre in a hospital that has high volumes of pituitary surgery.
Such an endocrinologist may be called a neuro endocrinologist, and is well versed with all issues related to the pituitary gland.
To get the most out of a visit to an endocrinologist you should be able to answer the following questions with respect you our husband's history:
Weight gain or weight loss over time?
Body temperature: fluctuations? Exaggerated? Steady?
Body temperature regulation (you already confirmed that)
Mental function: does he have brain fog? Is he slower than previously?
Depression: does he have this and if so, is it sometimes or often?
Does he have pain? If so where is the pain; how strong is it and how long does it last?
Does he crave food? If so, sweets? Salty? Fats?
How is his night-time sleep? Sound or does he wake up dying the night.
The more facts you can give an endocrinologist or neurologist the more you and your husband will get out of the visit.