Benign lesions in skin of color

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Description	This chapter describes the dermoscopy of various benign lesion in skin of color such as dermatofibroma, angioma, seborrheic keratoses and sebaceous hyperplasia
Author(s)	Richard Usatine
Responsible author	Richard Usatine → send e-mail
Status	open
Status update	July 19, 2023
Status by	Ralph P. Braun

Skin of color, Benign lesions, Angioma, Dermatofibroma, Soc, Sebaceous hyperplasia, Seborrheic keratoses 06-Benign lesions in skin of color – cite! 06-Benign lesions in skin of color (message) 06-Benign lesions in skin of color – participate!

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Nevi

The following 4 studies describe how skin type impacts the structure and color of melanocytic nevi:

1. Tuma et al. performed the first study that compared the dermoscopic differences in acquired melanocytic nevi between skin types V/VI to that of skin types I/II. They concluded that dermoscopy of the acquired melanocytic nevi in skin type V/VI showed a reticular pattern, brown color, and tendency toward central hyperpigmentation whereas the acquired nevi in skin type I/II showed a light-brown color and a tendency toward structureless pattern and multiple areas of hypopigmentation (figure 1). Also, nevi in skin type V/VI displayed a higher frequency of gray and black colors. Black color (as dots centrally, blotches, and pigmented network) was not seen in the light-skinned group but was found in almost 5% of the lesions in the dark-skinned individuals.

Figure 1. These images of acquired melanocytic nevi are adapted from Tuma et al. Note the nevus on lighter skin (left) demonstrates a light-brown color, structureless pattern, and multiple areas of hypopigmentation. The nevus on darker skin (right) demonstrates a reticular pattern, dark brown color, and central hyperpigmentation.

2. Lallas et al. analyzed 300 naevi from subjects with skin type V and VI and found significant differences in the naevus pattern between these two groups. The majority of naevi in skin type V displayed a reticular pattern, whereas persons with skin type VI more frequently exhibited a structureless pattern. Skin type V individuals typically had dark brown colored nevi whereas skin type VI individuals were more likely to have black, blue and grey colors in their nevi.

3. Fonseca et al. performed a cross-sectional analysis of the dermoscopic patterns and structures of melanocytic naevi on the back and legs of adolescents, including a minority of participants with skin of color. Regarding nevi on the back, they found that Hispanic ethnicity, darker hair color and darker skin color were associated with a relatively higher percentage of reticular nevi and a lower percentage of homogenous nevi (compared to nevi on the backs of non-Hispanic whites, those with lighter hair color, and those with lighter skin color). On the legs, those with darker skin color had a higher percentage of reticular nevi and a lower percentage of homogenous nevi compared to those with lighter skin color.

4. Zalaudek et al. used dermoscopy to study how nevus type is related to skin type in persons with skin types I to IV.4 While they did not include persons of skin types V and VI, they did look at intermediate skin types that can be found in persons of lighter skin of color. They found these trends with darkening of skin type:

• Decreasing prevalence of light brown color
• Increasing prevalence of dark brown color
• Decreasing prevalence of central hypopigmentation
• Increasing prevalence of central hyperpigmentation

Need permission: The following graphs were adapted from Zalaudek et al. These are graphical representations of the aforementioned trends in nevus morphology.

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  nevus on type II skin, with light brown color and central hypopigmentation

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  nevus on type V skin with dark brown color and central hyperpigmentation.

The following images are from the ISIC archive. Note the light brown color and central hypopigmentation of the nevus on type I skin and the dark brown color and central hyperpigmentation of the nevus on type V skin.

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  Nevus on type I skin – hypopigmented center

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  Nevus on type V skin – hyperpigmented center

Intradermal nevi

There has been no literature published regarding the dermoscopic features of intradermal nevi in patients of color. Below are representative images of intradermal nevi.

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Note the appearance of the intradermal nevus on a patient of color (left) compared to the intradermal nevus on a patient with light skin color (right). The intradermal nevus on the patient of color has increased pigmentation.

Acral (volar) nevi

The following is a compilation of literature published on acral nevi in skin of color patients:

1. Tan and Stein recognize the diagnostic challenges of acral lesions due to the unique nature of acral surfaces. Dermoscopy assists in the differentiation of benign from malignant lesions, which is of particular importance on examination of skin of color patients, since acral lentiginous melanoma makes up a significant proportion of melanoma cases in this population. Visualization of the parallel ridge pattern (parallel linear pigmentation along the ridges of the dermatoglyphics on volar surfaces) has high sensitivity and specificity for the diagnosis of acral lentiginous melanoma (86% and 99%, respectively). Common features of benign, acquired acral nevi include parallel furrow, lattice-like, and fibrillar patterns.

2. Madankumar et al. studied acral melanocytic lesions in skin of color and white patients in the United States. Acral pigmented lesions were more commonly seen in those with Fitzpatrick skin types IV to VI compared to skin types I to II. The following were the most common dermoscopic patterns of acral nevi in skin-of-color patients:

• Parallel furrow (43%)
• Lattice-like pattern (13%)
• Homogenous pattern (10%)

In comparison, the most common patterns in non-Hispanic white patients were:

• Parallel furrow (48%)
• Lattice-like pattern (16%)
• Fibrillar pattern (8%)

3. Barquet et al. studied a diverse Latin American population in Uruguay. The Uruguayan population is heterogeneous; most of the population is of European descent (mainly Spanish and Italian), but there are also people of indigenous (1---20%) and African (7---15%) descent. The following dermoscopic patterns were seen among 158 acral volar nevi in 80 patients:

• Parallel furrow pattern (51.3% of nevi)
• Lattice-like pattern (13.3%)
• Homogeneous pattern (12.7%)
• Globular pattern (9.5%)
• Fibrillar pattern (7%)

They concluded that no new dermoscopic patterns were observed in this population; the patterns described in Asian and European literature also apply to their population.7

Here are some examples of acral nevi:

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  2 examples of parallel furrow patterns in AA persons

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  Benign lattice pattern on palms of an AA person

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  A 1 cm hyperpigmented macule on the sole of a 30-year-old African-American man.

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  Note the fibrillar pattern. A biopsy was performed because of its size and rapid growth. It was determined to be a benign acral nevus

Dermatofibroma

A dermatofibroma is a scar-like benign tumor that is firm to palpation and often shows a dimple sign. On dermoscopy it typically shows a central hypopigmented or pink scar-like area surrounded by fine reticular network.

Classic dermoscopic features:

• Delicate pigment (reticulated) network at the periphery of the lesion.
• A central scar-like white or pink patch with or without shiny white lines

Additional dermoscopic features:

• Ring-like globules
• White network -white lines surrounding small islands of brown pigment or surrounding globule-like (i.e., “ring-like”) structures.
• Homogenous areas with brown color
• Vascular structures
• Rarely comedo-like openings, scale, ulceration, peripheral collarette fissures, ridges and mammillated surface.

The best description of DF in skin of color was performed in Morocco from 2015 to 2016 and included 100 cases. All the patients had a dark skin phototype (Fitzpatrick scale types IV and V). A total of 14 morphological dermoscopic structures were distinguished, and 17 dermoscopic patterns were observed, with the most common pattern being the central white patch and peripheral pigment network (21%).

Examples in a variety of patients with skin of color

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  The arm of a 48-year-old African-American woman with a dermatofibroma.

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  1. Peripheral fine network – blends into surrounding darker pigmentation 2. Central white or pink scar-like area – less pink 3. Ring-like globules – annular edge is less visible

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  African-American woman - leg

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  Central shiny white structures that are creating polygonal patterns (not one of typical 10 patterns described by Zaballos et al.)

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  31yo Indian man – arm -clear ringlike globules with white scar like center and particular network fine on the edge

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  African-American woman leg

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  Note the barely visible short shiny white lines in the center

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  DF in a 53 yo Chinese man

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  26-year-old Hispanic female – note how the ring globules have more visible ring edges with the lighter skin - Fitzpatrick IV

Never forget to do the pinch test:

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  Pinch test of a DF on the abdomen

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  DF with visible vessels and more keratin on the surface than usual. Central white lines/scar are typical.

Angioma and other vascular lesions

Angioma

Angiomas are benign vascular tumors that have the dermoscopic features of lacunae and septae. These features are found independent of the color of the skin. Angiomas can have colors that vary from a light pink to a deep purple regardless of the skin type. Whether angiomas are more likely to be lighter pinks in light-skinned persons and darker reds and purples in dark skinned persons is possible but not proven.

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  Pink colored angioma in a light-skinned person.

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  Violaceous colored angioma in a darker-skinned individual.

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  Two cherry angiomas on the back of a Hispanic man.

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  Note the lacunae and septae are present and how the colors can vary in one patient.

Angiokeratoma

Angiokeratomas are acquired vascular lesions that present as shiny, soft, dark red to violaceous, 2–10 mm papules which may develop a blue-violaceous to black color and a surface scale.

Dermoscopy

• Dark lacunae: sharply demarcated, ovoid structures with a dark blue, dark violaceous or black color.
• Blue-White veil: confluent blue pigmentation with an overlying whitish haze.
• Ulceration and surface scale may be present.
• Rarely, a rainbow pattern may be present.

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  Angiokeratoma on foot of a Hispanic woman for 15 years.

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  Dermoscopy showing violaceous lacunae, overlying whitish haze and surface scale.

Pyogenic Granuloma

Pyogenic granuloma (PG) is a relatively common benign acquired friable vascular growth of the skin and mucous membranes often started by trauma. PG is a misnomer as it is neither pyogenic nor granulomatous. However, it often has a purulent-appearing exudate that explains how it got its name. A more accurate name in use is “lobular capillary hemangioma”.

Dermoscopy

• Reddish or red-whitish homogeneous area: a structureless zone whose color varies from completely red to red with whitish zones.
• White collarette: a ring-shaped or arcuate squamous structure that is usually located at the periphery of the lesions.
• White rail lines: white streaks that intersect the lesion.
• Vascular structures (dotted vessels, hairpin vessels, linear-irregular vessels, telangiectasias, polymorphous vessels).
• Ulceration may be present

The most frequent dermoscopic pattern of PG consists of reddish homogenous areas separated by white lines resembling rails and surrounded by a white collarette. Dermoscopy of pyogenic granulomas are not known to vary by skin type.

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  Pyogenic granuloma on the arm of a 41-year-old Hispanic woman.

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  Note the red lacunae and the white septae that appear similar to an angioma.

Kaposi’s sarcoma

Low-grade malignant vascular tumor caused by human herpesvirus-8 (HHV-8) producing a vascular proliferation.

Dermoscopy

• Homogeneous pattern with differing colors (i.e., whitish, pinkish, reddish, bluish, or violaceous) in different lesions in the same patient.
• Rainbow-like appearance: multicolored areas showing various colors of the rainbow spectrum.
• Whitish structureless areas, vascular structures, scale, and a white collarette may also be seen.

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  Classic Kaposi’s sarcoma in an 89-year-old Hispanic woman who is HIV negative.

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  There is a pink to violaceous color with a hazy brown border and some small white lines and out of focus vessels.

Lymphangioma circumscriptum

Malformation involving lymphatic vessels that may be present at birth or occur later typically from trauma (including postsurgical). The clinical appearance has been described as looking like frog spawn. There is no known variation based on skin color.

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  Lymphangioma circumscriptum in a 35-year-old Hispanic man related to trauma.

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  Note how the blood layers out at the bottom of the lymph filled vessels as blood is heavier than lymphatic fluid. I call this the “hyphema sign”.

Note how this resembles the hyphema that might be seen in an eye that has experienced trauma in which there is bleeding in the anterior chamber:

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This has been incorrectly compared to hypopyon which consists of white blood cells that create a white layer at the bottom of the anterior chamber in iritis:

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Courtesy of the Color Atlas and Synopsis of Family Medicine. Usatine R, Smith M, Mayeaux EJ, Chumley H. The Color Atlas and Synopsis of Family Medicine, 3rd Edition. McGraw-Hill, New York, 2018.

I suggest it is time to rename the sign the “hyphema sign”.

Seborrheic keratoses

Seborrheic keratoses are the most common benign epithelial lesion in adults. Their dermoscopic features have been well described in the chapter above. The following schematic shows the most typical features.

Schematic of SK

Seborrheic keratoses are found with shades of colors that span light brown to dark brown. They can also have multiple shades of brown and areas of white within a single benign lesion. The darkest SKs can mimic melanoma clinically which makes the understanding of the dermoscopic features so important.

There is no data on how SKs in darker skin compare to SKs in lighter skin, but many have observed that dark SKs are common in dark skin.

Examples of darker SKs in persons with skin of color

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  Large dark cerebriform SK on the face of a Hispanic woman.

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  Dermoscopy shows ridges and fissures (gyri and sulci)

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  An SK on the arm of an African American woman.

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  Dermoscopy shows a cerebral form pattern made up by dark brown keratin ridges.

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  Large dark brown SK on the back of an African American woman

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  Dermoscopy shows fat fingers on the periphery caused by keratin ridges. This was biopsied because the fat fingers mimicked streaking/pseudopods.

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  Small dark SK in a preauricular location of a Hispanic man.

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  Dermoscopy is consistent with negative network however the biopsy demonstrated this to be an SK.

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  Sk thigh 85-year-old African American woman – well demarcated border and short keratin ridges

Sebaceous hyperplasia

Sebaceous hyperplasia represents enlarged sebaceous glands principally found on the forehead, cheeks and nose in older adults. They can be found in persons of all skin colors and are typically 2 to 5 mm in diameter with a yellowish-white color and a light brown central opening. Due to some prominent vessels they may be mistaken for a basal cell carcinoma. Fortunately, dermoscopy almost always allows us to distinguish them from a BCC.

Dermoscopic features of sebaceous hyperplasia in all skin types include:

• White to yellowish-white globules that resemble popcorn in appearance. When the color is more yellow think of them as buttered popcorn (the butter is the sebum).
• Crown vessels are fine branching vessels that are more prominent on the periphery and do not cross the midline.
• Light brown central umbilication of the pilosebaceous unit. It has been described having the appearance of a round Bonbon caramel toffee.

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  Sebaceous hyperplasia in a Hispanic woman.

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  The sebaceous hyperplasia has all the features described above. The darker skin background makes it easy to distinguish the sebaceous hyperplasia from the surrounding skin.

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  Sebaceous hyperplasia in a man of African descent with dark skin. The darker skin background makes it easy to distinguish the sebaceous hyperplasia from the surrounding skin.

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  Sebaceous hyperplasia in a white man. Note how it does not stand out as readily from the surrounding pink skin.

Links to additional chapters on Skin of Color

• Dermoscopy of Skin of Color