Thanks for your question!
Have you seen a dermatologist about this? I'm not sure this is related to the pimple that you had 5 years ago. It could be an ingrown hair or something known as a sebaceous or "Fatty" cyst. It's very common and non-cancerous but basically it looks like a lump under your skin. Depending on the location and its size, some doctor will opt to remove it with a simple surgical procedure that requires a local anesthetic. Please schedule an appointment with your dermatologist and keep us posted.