Malignant lesions in skin of color
|Description||This chapter describes the dermoscopy aspect of malignant lesions in skin of color such as basal cell carcinoma, squamous cell carcinoma and melanoma|
|Responsible author||Richard Usatine → send e-mail|
|Status update||August 19, 2023|
|Status by||Ralph P. Braun|
Skin of color, Malignant lesions, Basal cell carcinoma, Squamous cell carcinoma, Melanoma 06-Malignant lesions in skin of color – cite! 06-Malignant lesions in skin of color (message) 06-Malignant lesions in skin of color – participate!
Basal cell carcinoma (BCC)
Basal cell carcinoma (BCC) is the most common malignancy.  It is most prevalent in those of light and intermediate skin types, and only rarely affects those of darker skin tones. Unfortunately, the lower incidence and lack of surveillance frequently results in delayed diagnosis, increased morbidity, and poorer outcomes for this population.  Health inequities, poverty and lack of healthcare access also contribute to delayed diagnosis and worse outcomes.
The dermoscopic features and structures of BCC have been very well described and delineated in the literature. A summary of these features and structures can be found here: https://dermoscopedia.org/Basal_cell_carcinoma
The following schematic is a great overview of BCC features.
|File created by Natalia Jaimes.|
Despite this extensive knowledge about the dermoscopy of BCCs, very little has been reported about the dermoscopy of BCCs in patients of color. The most comprehensive dermatology article on skin cancer in skin of color does not even mention dermoscopy once.  Therefore, we will summarize dermoscopy features of BCC in patients of color here.
We will divide the section up by the most common BCC types:
Nodular basal cell carcinoma
The central ulceration is visible dermoscopically and clinically but is not specific for one type of skin cancer. The dark pigment on the border resembles leaf-like structures, dark globules or pseudopods of melanoma. This is another example of how a darkly pigmented nodular BCC in skin of color can mimic a melanoma.
In summary, many nodular BCCs in patients of color are darkly pigmented, and have one or more of the following dermoscopic features:
- Arborizing vessels
- Shiny white blotches and strands
- Blue-gray ovoid nests
- Blue-gray non-aggregated globules
It is also important to note that some BCCs in patients of color have features that mimic melanoma (i.e. blue white veil).
Superficial basal cell carcinoma
In summary, the following are some dermoscopy features seen in superficial BCCs in patients of color:
- Leaf-like structures
- Spoke-wheel structures
Morpheaforme/sclerosing/infiltrative basal cell carcinoma
Squamous cell carcinoma SCC
Cutaneous squamous cell carcinoma (sSCC) is often described as the most common skin malignancy in those with the darkest skin types but is less common than BCC in ethnic groups with intermediate pigmentation, including Hispanics and Asians. However, based on the most recent data in the US, BCC was more prevalent than cSCC in all ethnicities, including Black patients (BCC:SCC ratios, 1.60 for Asian patients, 1.45 for Black patients, 2.00 for Hispanic patients, and 1.69 for White patients of all ages). 
Known risk factors for SCC in skin of color patients include chronic scarring processes, inflammatory conditions, HPV, immunosuppression, sites of radiation therapy, and exposure to chemical carcinogens. In comparison to patients with light skin, ultraviolet radiation exposure is not as an important a risk factor for SCC with the darkest skin.
SCC in situ (Bowen’s disease - BD) is frequently seen in patients with intermediate pigmentation and may be more likely to manifest as pigmented Bowen’s disease. The epidemiology of this has not yet been established, but nonpigmented Bowen’s disease is very uncommon in the darkest skin types in our experience.
Invasive cSCC often appears as a fungating mass with ulcerations and excess keratin. These masses can be nodular, plaque-like, papillomatous or exophytic. SCC of the keratoacanthoma type has the typical appearance of a central keratin core with a rolled pearly raised border and is histologically well-differentiated. Less differentiated and more advanced cSCC has less visible keratin and appears as a vascular mass with abnormal vessels.
- Scale (rough texture) is present in almost all lesions
- Glomerular (coiled) vessels
- Focally distributed towards the periphery
- Diffusely present throughout lesion
- Aligned linearly within lesion
- White circles
- Brown circles
- Rosettes (seen with polarized light)
- Brown dots aligned in a linear fashion
- Radially arranged brown lines
- Strawberry pattern seen in actinic keratosis (AK)
- Hairpin (looped) vessels with a white halo can be seen in keratoacanthomas (KA). In KA these looped-vessels tend to be aligned at the periphery.
- Polymorphous vascular pattern composed of dotted, short linear and long linear irregular (serpentine) vessels.
See chapter on SCC for further information.
SCC superficially invasive
SCC of the Keratoacanthoma type
SCC poorly differentiated
Next 4 images courtesy of Dr. Bengü Nisa Akay
Melanoma occurs less frequently in persons of color but is associated with higher rates of morbidity and mortality. In a systematic review performed by Higgins et al., the following conclusions were made: 
- African Americans have deeper tumors at time of diagnosis in addition to increased rates of regionally advanced and distant disease. Lesions are generally located on the lower extremities and have an increased propensity for ulceration. Acral lentiginous melanoma (ALM) is the most common melanoma subtype found in AA patients.
- In Hispanics, superficial spreading melanoma is the most common melanoma subtype. Lower extremity lesions are more common relative to Caucasians. Hispanics have the highest rate of oral cavity melanomas across all ethnic groups.
- In Asians, acral and subungual sites are most common. Specifically, Pacific Islanders have the highest proportion of mucosal melanomas across all ethnic groups.
Local dermoscopic features described for melanoma in general (mostly studied in light skinned populations) are the following:
Melanoma specific structures:
Current literature on melanoma in SOC:
December 2020, Pubmed search of dermoscopy melanoma “skin of color” comes up with 2 references only:
Tan A, Stein JA. Dermoscopic patterns of acral melanocytic lesions in skin of color. Cutis. 2019 May;103(5):274-276. 
Madankumar R, et al. Acral melanocytic lesions in the United States: Prevalence, awareness, and dermoscopic patterns in skin-of-color and non-Hispanic white patients. J Am Acad Dermatol. 2016 Apr;74(4):724-30.e1. doi: 10.1016/j.jaad.2015.11.035. Epub 2016 Jan 20. PMID: 26803347.
(Note that none of the lesions were melanomas)
A similar search on “dermoscopy melanoma African” added this article: de Giorgi V, Trez E, Salvini C, Duquia R, De Villa D, Sestini S, Gervini R, Lotti T. Dermoscopy in black people. Br J Dermatol. 2006 Oct;155(4):695-9. doi: 10.1111/j.1365-2133.2006.07415.x.  Performed in Brazil, 100 clinically suspicious cases, 79 were Clark naevi, 15 seborrhoeic keratoses, four blue naevi, one dermatofibroma and one melanoma. Darker pigmentation of the skin did not impede the identification of single dermoscopic features. With only one melanoma, it is hard to draw conclusions about sensitivity of the features described originally in lighter skin.
A similar search on “dermoscopy melanoma Asian” found 13 articles including some relating to Hispanic skin. Most of these articles dealt with ALM. The Asian population is clearly the most studied group among all types of skin of color for dermoscopy of melanoma. We will address the details under the ALM section.
Superficial Spreading Melanoma
Lentigo Maligna Melanoma
While LMM can occur on the face and other sun-damaged areas.
- Annular-granular pattern
- Asymmetric follicular openings
- Gray dots/granules around ostial openings
- Circle within circle sign
- Angulated lines forming rhomboids
Acral lentiginous melanoma (ALM)
Many articles in the medical literature state that acral lentiginous melanoma (ALM) is the most common type of melanoma in Asians and persons of African descent.
Data from the US Surveillance, Epidemiology, and End Results (SEER) registry from 2006 to 20152 showed % of ALM by ethnic group as:
- Black Americans (blacks) -34%
- Asian/Pacific Islanders -23%
- Hispanic whites – 9%
- Non-Hispanic whites – 1%.
Studies outside the US have shown percentage of ALM amongst all melanoma cases by ethnic groups:
Acral Volar patterns: melanomas on the palms and soles
- Parallel ridge pattern
- Atypical fibrillar pattern
- Diffuse pigmentation with multiple shades of brown
- Multi-component pattern
In general, it is clear that ALM is a major cause of morbidity and mortality in skin of color patients. Therefore, the dermoscopy of these melanomas needs to be clearly understood and clinically applied.
Other specific melanoma locations of interest are covered in the next subchapters.
Links to additional chapters on Skin of Color
- Marzuka & Book: Basal cell carcinoma: pathogenesis, epidemiology, clinical features, diagnosis, histopathology, and management. Yale J Biol Med 2015;88:167-79. PMID: 26029015.
- Ahluwalia et al.: Basal cell carcinoma in skin of color. J Drugs Dermatol 2012;11:484-6. PMID: 22453586.
- Gloster & Neal: Skin cancer in skin of color. J Am Acad Dermatol 2006;55:741-60; quiz 761-4. PMID: 17052479. DOI.
- Hogue & Harvey: Basal Cell Carcinoma, Squamous Cell Carcinoma, and Cutaneous Melanoma in Skin of Color Patients. Dermatol Clin 2019;37:519-526. PMID: 31466591. DOI.
- Lukowiak et al.: Association of Age, Sex, Race, and Geographic Region With Variation of the Ratio of Basal Cell to Cutaneous Squamous Cell Carcinomas in the United States. JAMA Dermatol 2020;. PMID: 32845319. DOI.
- Higgins et al.: Clinical Presentations of Melanoma in African Americans, Hispanics, and Asians. Dermatol Surg 2019;45:791-801. PMID: 30614836. DOI.
- Tan & Stein: Dermoscopic patterns of acral melanocytic lesions in skin of color. Cutis 2019;103:274-276. PMID: 31233579.
- Madankumar et al.: Acral melanocytic lesions in the United States: Prevalence, awareness, and dermoscopic patterns in skin-of-color and non-Hispanic white patients. J Am Acad Dermatol 2016;74:724-30.e1. PMID: 26803347. DOI.
- de Giorgi et al.: Dermoscopy in black people. Br J Dermatol 2006;155:695-9. PMID: 16965417. DOI.
- Huang et al.: Acral Lentiginous Melanoma: Incidence and Survival in the United States, 2006-2015, an Analysis of the SEER Registry. J Surg Res 2020;251:329-339. PMID: 32208196. DOI.
- Mun et al.: Dermoscopy of Melanomas on the Trunk and Extremities in Asians. PLoS One 2016;11:e0158374. PMID: 27391775. DOI.
- Lino-Silva et al.: Melanoma in Mexico: Clinicopathologic Features in a Population with Predominance of Acral Lentiginous Subtype. Ann Surg Oncol 2016;23:4189-4194. PMID: 27401447. DOI.