fat biopsy

I recently took a patient to the operating room to perform a biopsy of the abdominal wall fat pad. About a square 1/2 inch by 1/2 inch of fat from the abdominal wall was taken....no skin was taken, just fat. This is used by pathology to diagnose amyloidosis. I can't find a cpt code that fits. I found a suggestion of 114xx series on the internet, but I didn't excise a benign lesion...or did I? The only other code I can think of is skin biopsy (even though no skin was biopsied) - 11100. I just refuse to accept $40 for taking a patient to the operating room...This really cant be done at bedside because its a relatively deep biopsy. Can anyone suggest anything?

Could you use

12031? Depends on your closure. Or use 11100 and then the modifier for prolonged surgery and send your op note and a letter.