Derm Dx: Growth on the Left Index Finger

A 58-year-old man presents for evaluation of a mass affecting his left index finger. The lesion has been gradually increasing in size over the past 3 years and has only recently become bothersome. He is currently taking medication to control hypertension and hyperlipidemia. He denies arthritis, gout, or history of trauma to the affected area.

Can you diagnose this condition?