Sebaceous cyst on cheek, got cortisone shot 4 months ago. There's a divot on my cheek. Will the divot heal on its own? (Photo)

The treatment for a sebaceous cyst is surgical removal, not cortisone injection! You probably had too much cortisone injected and it caused atrophy of the fat in the area. Fillers, Sculptra, or Fat transfer may help improve the appearance. Best wishes.

Sebaceous cysts on the face are not typically treated with cortisone injections. If in fact you did have a sebaceous cyst then the proper treatment is surgical removal. It is unfair for anyone to comment on your specific case without having seen BEFORE photos or having examined you in person. That being said, steroid injections are well known to have as a side effect the possibility of fat atrophy, an indentation, or depression in the area of treatment. Pigment (color) changes are also possible. You seem to have both. This is unlikely to go away on its own if it has already been 4 months since your cortisone injection. Revision of the area with a complete excision may help. This is a challenging situation.  Please make sure you choose someone with extensive experience in cosmetic facial surgery. Best wishes.
Damon B. Chandler, MD
Harvard-Penn Trained Oculofacial Plastic Surgeon