The incident, which was captured on surveillance camera, happened around 9:50 a.m. inside Central Cellars.
The man, identified as Otis Gooding, was working in the store when the e-cigarette started sparking in his pocket. A colleague said it was sizzling and then caught fire. He said it looked like he had a pocket full of firecrackers.
Gooding is seen patting his leg and reportedly burned his hand.
He was taken by private ambulance to a local hospital, where he's in stable condition. His attorney, Sanford Rubenstein, said he was admitted to the burn unit for treatment and will require surgery.
This photo shows the aftermath of the explosion:
The colleague said the e-cigarette had a high-voltage battery, but there was no indication why it caught fire.
There was no impact to train service.