Mucosa in Skin of Color
Dermoscopy of mucous membranes has been named mucoscopy. At this time there are no studies that compare dermoscopy of mucous membranes from persons of color with persons of lighter skin. In fact, the literature on mucoscopy is small due to the fact that melanomas are rare on mucous membranes such as the lips, oral mucosa and anogenital regions. While squamous cell carcinoma is more common than melanoma in these regions due to HPV, there is still little written on the dermoscopy of these lesions. We will review some of the existing literature and present examples from our practice and the chapter on mucous membranes in the general area of Dermoscopedia.
In one study, benign pigmented lesions of the mucocutaneous junction and mucous membranes presented with:
- dotted-globular pattern (25%)
- homogeneous pattern (25%)
- fish scale-like pattern (18.8%)
- hyphal pattern (18.8%)
- (note the fish scale-like pattern and hyphal pattern are considered to be variants of the ring-like pattern)
Melanomas of these sites showed:
- multicomponent pattern (75%)
- homogeneous pattern (25%) 
In a multicenter study by the International Dermoscopy Society (IDS), the combination of blue, gray, or white color with structureless zones are the strongest indicators of malignant mucosal lesions in dermoscopy. 
Labial melanotic macules
Squamous cell carcinoma of the lip
Melanoma of the lip
A retrospective dermoscopic study was conducted on 87 genital lesions with histopathologically proven benign melanosis. The patterns found were:
- ring-like pattern (32%) characterized by multiple round to oval structures, white to tan, with dark brown, well-defined regular borders
- structureless and globular-like patterns (21%)
- parallel pattern (17%)
- cobblestone-like and reticular-like patterns (5%)
The ring-like pattern was frequently associated with multifocality and simultaneous occurrence at the labia majora and the labia minora.
Photographs from: Andreas Blum, Olga Simionescu
A great summary chart from the Mucosa chapter in Dermoscopedia by Andreas Blum, Olga Simionescu:
|Parallel pattern||The pigmentation is linearly distributed (wispy linear streaks)||Vulvar melanosis, in focal areas of mucosal melanoma, pigmented warts|
|Structureless (homogenous) pattern||Diffuse light to dark brown, black, grey-blue pigmented or white areas devoid of any visible structures. In white structures polymorphic vessels could be visible||Highly suggestive for melanoma, mainly in elderly people|
|Reticular pattern||Honeycomb pattern of pigmented network|
|Dotted globular pattern||Dots and globules||Melanocytic lesions |
|Ring-like pattern||Do not form a complete circle (“fish scale like structures”)||Melanosis|
Links to additional chapters on Skin of Color
- Lin et al.: Dermoscopy of pigmented lesions on mucocutaneous junction and mucous membrane. Br J Dermatol 2009;161:1255-61. PMID: 19673880. DOI.
- Blum et al.: Dermoscopy of pigmented lesions of the mucosa and the mucocutaneous junction: results of a multicenter study by the International Dermoscopy Society (IDS). Arch Dermatol 2011;147:1181-7. PMID: 21680757. DOI.
- Ferrari et al.: The ringlike pattern in vulvar melanosis: a new dermoscopic clue for diagnosis. Arch Dermatol 2008;144:1030-4. PMID: 18711077. DOI.