Updated

For two years, Rosemary McGinn’s friends and family thought she was constantly drunk – when she was actually stone sober.

McGinn, 53, had assumed her odd behavior was caused by her hypoglycemia, so she would often carry around snacks to keep her blood sugar up, according to a report from Mount Sinai Medical Center in New York.

“When my sugar would suddenly crash, it was like I was drunk,” McGinn said.  “I would become very combative, not knowing what I was saying and sway back and forth.”

But after a checkup with Dr. Ronald Tamler, clinical director of the Mount Sinai Diabetes Center, McGinn discovered that her condition was much more serious.

“A normal blood sugar is around 100 milligrams/deciliter, and most people start feeling poorly when their sugar dips below 70,” Tamler said. “But Rosemary had a sugar of 20. That level usually leads to seizures and coma.”

McGinn was subsequently diagnosed with insulinoma, a rare pancreatic tumor that constantly makes insulin – even when blood sugar is too low.  After undergoing a 90-minute surgery at Mount Sinai, McGinn’s tumor was removed, and she no longer exhibited odd behaviors.

To better understand the mechanisms that produce insulin, Tamler and his colleagues had McGinn’s tumor frozen after it was removed and incorporated it into Mount Sinai’s Tissue Bank, a database of samples and information used for research.

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