When a dark spot appears inside the mouth, it often prompts questions about its nature and whether it signals a serious condition. Oral melanotic macules (OMMs) are common, benign dark spots that can develop on the lips or within the oral cavity. Understanding these spots can alleviate concerns about their appearance and persistence.
What Are Oral Melanotic Macules?
Oral melanotic macules are flat, well-defined areas of increased pigmentation that appear on the mucous membranes inside the mouth. They present as brown, black, or grayish-brown patches, usually less than 7 millimeters in diameter, with a uniform color and regular border. These macules are harmless and not cancerous. Common locations include the lower lip, gums (gingiva), inner cheek (buccal mucosa), and the roof of the mouth (palate).
OMMs result from an overproduction and accumulation of melanin, the natural pigment that colors skin, within tissues. Unlike freckles, their appearance is not influenced by sun exposure. While OMMs are benign and do not transform into cancer, a biopsy may be performed to confirm diagnosis and distinguish them from more serious conditions like oral melanoma.
Do They Go Away?
Generally, oral melanotic macules are stable and do not spontaneously disappear. Their persistence is normal for these benign lesions and not a cause for concern. While some sources suggest they may fade or even go away over time, especially those related to post-inflammatory pigmentation, OMMs are considered permanent.
Macules form from increased melanin production by melanocytes in the basal layer of the oral epithelium. This localized pigment increase, without an increased number of melanocytes, contributes to their stable, long-lasting presence. Their benign nature means persistence does not indicate malignancy.
When to Seek Professional Advice
While oral melanotic macules are harmless, consult a dentist or doctor for any new or changing dark spots in the mouth. A professional evaluation helps diagnose the lesion and rule out other conditions, including oral melanoma, a rare but aggressive cancer. Signs warranting immediate professional investigation include changes in size, shape, or color, irregular borders, elevation, pain, or bleeding.
Oral melanoma presents with features like asymmetry, irregular borders, varied coloration (red, white, blue, brown, or black), and may be larger than 6 millimeters. Unlike OMMs, oral melanoma can also present as a mass or plaque. A biopsy is necessary to differentiate between a benign macule and melanoma, especially if the lesion is large, growing, or in higher-risk areas like the palate in older male patients. Professional diagnosis provides peace of mind and ensures appropriate management if a serious condition is identified.