<s>[INST] I don t know how long these have been here, but I have 4 dark spots in my mouth on the inside of my cheeks I can t tell if there dark red or brown but they look like freckles inside my mouth but I ve been in and out of the hospital lately for my stomach I ve had horrible stomach aches for 6 months now does that have anything to do with my sotmach? [/INST] Oral pigmentation can occur due to variety of reasons. Local irritants such as smoking may cause melanosis. These oral pigmented lesions result from cellular hyperplasia that can range from benign nevi to fatal oral melanoma. It may also be drug induced. Pigmentation occurs due to chronic irritation and post trauma too. </s>