I have had gynecomastia for over a year. it was attributed to finesteride which i stopped 6 months ago. tenderness persists on 1side. is this unusual ?

Sometimes: Effect of Finasteride could be long lasting or even permanent. If you have a palpable residual mass, show it to your doctor because it could be, in rare cases, a tumor.

NO: Yes few develop gynecomastia in 3 % when discontinued may or may not reverse to normal size , also slight increased incidence of male breast cancer . Make sure to see your doctor , if needed get a biopsy done