"Buffalo hump" and purple stretch marks certainly sounds like classic symptoms of Cushing's disease. Here's a link to a good patient-information site and organization: http://www.cushings-help.com/toc.htm
She may need to see an endocrinologist and/or a neurosurgeon (if she has it and it is the type due to a pituitary tumor). If her initial bloodwork is clearly abnormal and makes the diagnosis, great - if it comes back normal, you may need to see an endocrinologist and push for further testing - sometimes the diagnosis of Cushing's can be difficult to make. Of course, if the MRI shows something obvious like a pituitary growth, that may help clinch the diagnosis.
