I received (missed) two calls from this number. I believe they were to inform me of medications that are ready to be picked up. Just knowing that the calls originated on Ft. Sam, and that I was expecting a notification from them allows me to make this deduction.
To address 'Jack's' comment of sexual pranks. Any calls originating from BAMC (Brooke Army Medical Center)and potentially all of Ft. Sam will use this number. Similar to all calls from WHMC (Wilford Hall Medical Center - USAF), all calls originating from the hospital, if not the whole base, will be shown as 210-292-0000