III.14
III.14.1 Definition
Nevi with particular pigmentation are defined herein as benign melanocytic nevi that do not contain significant amounts of brown color.
Chapter III.14
Nevi with Particular Pigmentation:
Black, Pink, and White Nevus
Iris Zalaudek, Robert Johr, Bernd Leinweber
III.14
III.14.2 Clinical Features III.14.2.1 Black Nevus
This variant of a benign melanocytic nevus is also referred to as a “hypermelanocytic nevus”
or “nevus of midlife.” [1] They appear as black macules often with a subtle touch of brown col- or at the periphery, 5 mm in size or even smaller typically located on the trunk and/or extremi- ties (Fig. III.14.1). Black nevi vary in number from a single lesion to more than 50, typically, but are not seen only in darker-skinned indi- viduals (Fitzpatrick photo-types III and IV) be- tween the ages of 16 and 30 years (“nevus of mid-life”). Because of the intense black color suggestive of melanoma, they are in the group of lesions that are referred to as melanoma simula- tors. A red flag of concern should always be raised when a black-pigmented lesion is found.
A single black nevus is more worrisome than multiple lesions.
Concerns about the diagnosis can be easily disarmed by its clinical hallmark, the “black la- mella.” This represents a removable pigmented scale located in the center or covering most of the lesion. With tape stripping the black lamella can be removed in most, but not all, lesions dis- playing local dermoscopic criteria. The pig- mented scale often is left on the tape, which confirms the banal nature of the lesion.
III.14.2.2 Pink Nevus
The worldwide distribution of this variant of a melanocytic nevus varies from country to coun- try, and even within regions of a single country.
Typically seen in individuals with fair skin type
Contents
III.14.1 Definition . . . .142
III.14.2 Clinical Features . . . .142
III.14.2.1 Black Nevus . . . .142
III.14.2.2 Pink Nevus . . . .142
III.14.2.3 White Nevus . . . .143
III.14.3 Dermoscopic Criteria . . . .143
III.14.3.1 Black Nevus . . . .143
III.14.3.2 Pink Nevus . . . .144
III.14.3.3 White Nevus . . . .144
III.14.4 Relevant Clinical Differential Diagnosis . . . .144
III.14.4.1 Black Nevus . . . .144
III.14.4.2 Pink Nevus . . . .144
III.14.4.3 White Nevus . . . .145
III.14.5 Histopathology . . . .145
III.14.5.1 Black Nevus . . . .145
III.14.5.2 Pink Nevus . . . .145
III.14.5.3 White Nevus . . . .145
III.14.6 Management . . . .145
III.14.6.1 Black Nevus . . . .145
III.14.6.2 Pink Nevus . . . .145
III.14.6.3 White Nevus . . . .146
References . . . .146
Nevi with Particular Pigmentation:
Black, Pink, and White Nevus
Iris Zalaudek, Robert Johr, Bernd Leinweber
III.14
(Fitzpatrick photo-types I and II) of all ages with other pigmented melanocytic nevi, they can be macules and papules (Fig. III.14.2) with varying shades of pink color. The papular le- sions are often soft, easily compressible, and at times have a single central hair. The number of pink nevi ranges from single to multiple lesions located on any part of the body including the scalp, where their hidden nature should be un- covered by a complete skin examination [2, 3].
III.14.2.3 White Nevus
This variant of melanocytic nevus is character- ized by white or pale pink macules on papules with accentuated skin markings and a silvery sheen when viewed with tangential lighting (Fig. III.14.3). They are located on the trunk or extremities in adults and vary from a few to hundreds of lesions usually but not always in fair-skinned individuals (Fitzpatrick photo- type I). White nevi are rare or under-reported and should be considered possible markers of melanoma development, because they are often found in individuals with a history of melanoma and/or have histopathological characteristics of dysplastic nevi [4].
III.14.3 Dermoscopic Criteria III.14.3.1 Black Nevus
Black nevi are characterized by a reticular pattern, typified by a fine brown pigment net- work with regular holes and meshes. Dots can also be seen; however, most of the criteria are hidden by the black lamella that appears as dark brown or black blotch of featureless color cover- ing most of, if not the entire, lesion (Fig. III.14.4).
No high-risk local criteria, such as streaks (typi- cal for spitzoid lesions), are ever seen which as- certains the dermoscopic diagnosis [5].
Fig. III.14.2. Clinical view of a pink nevus reveals a symmetric pink plaque. Note that on the surrounding skin pigmented nevi are present. Because this was the only pink lesion seen in this patient, excision was per- formed and histopathology revealed a benign nevus with mild dysplasia
Fig. III.14.1. Clinical image of a so-called black nevus shows a symmetric dark-colored plaque with a scaly sur- face. The surface scale is due to the black lamella, which can be easily removed by tape
Fig. III.14.3. Clinical view of multiple white nevi lo- cated on the back. When examined by tangential light, a silvery shiny surface with accentuated skin markings can be seen (left)
144 I. Zalaudek, B. Leinweber, R. Johr
III.14
III.14.3.2 Pink Nevus
Pink nevi can be featureless with only shades of pink color or feature poor with foci of light- brown color, remnants of fine pigment network, or teleangiectatic vascular structures. The vas- cular patterns are basically non-specific or may reveal dotted, “comma-shaped,” and larger lin- ear vessels that can be seen alone or in combina- tion (Fig. III.14.5) [6]. The larger arborizing ves- sels typical of basal cell carcinoma and other high-risk local dermoscopic criteria seen in pig- mented melanocytic nevi are absent.
III.14.3.3 White Nevus
White nevi are featureless and reveal only te- leangiectasias of the dermal plexus shimmering through the epidermis.
III.14.4 Relevant Clinical Differential Diagnosis
III.14.4.1 Black Nevus
Melanoma is the most important consideration in this clinical setting. Dysplastic nevi and Spitz nevi should also be included in the differential diagnosis. A single lesion is more worrisome than multiple symmetrical uniformly pigment- ed round to oval macules or papules with the typical black lamella.
III.14.4.2 Pink Nevus
A solitary pink macule or papule could be mela- nocytic or non-melanocytic, benign or malig- nant. Multiple pink lesions, even in their clini- cal features, are typically seen in fair skin types.
In these cases, regular follow-up should over- ride excision, although they could be a combi- nation of banal and dysplastic nevi. If there is just a single lesion, differentiation from non- melanoma skin cancer may be difficult, or even impossible, clinically or with dermoscopy.
No matter how old or young the patient is, a solitary pink lesion could also be amelanotic melanoma. Pediatric patients have a high per-
Fig. III.14.4. Dermoscopic view of the black nevus as shown in Fig. III.14.1. The central lamella appears as a structureless black blotch and covers the underlying regular and fine pigment network, which is seen at the border
Fig. III.14.5. Dermoscopy of the pink nevus shown in Fig. III.14.2. There is lack of specific structures which would allow the diagnosis of a benign nevus with extreme confidence. Because this nevus was the only pink lesion in a patient with a fair skin type and numerous nevi, excision was performed in order to rule out a malignant tumor
centage of amelanotic melanomas that do not fit the criteria of the typical pigmented melanoma [7]. In this clinical setting, “If in doubt, cut it out.”
III.14.4.3 White Nevus
The differential diagnosis of white nevus is ex- tensive and depends on the number and distri- bution of lesions plus the age and history of the patient. When few in number, consider flat warts as well as seborrheic and lichen planus- like keratosis. With multiple lesions consider post-inflammatory hypopigmentation, pityria- sis alba, idiopathic guatte hypomelanosis, hy- popigmented early vitiligo, morphea, lichen sclerosis et atophicus hypopigmented mycosis fungoides, and leprosy [4]. The silvery sheen seen with tangential lighting will be a clue to the diagnosis, which is finally made when the clini- cal picture is put together with histopathology.
III.14.5 Histopathology III.14.5.1 Black Nevus
Black nevus is characterized by melanocytes ar- ranged mainly along the basal layer (junctional nevus) and the finding of pigmented parakera- tosis in the stratum corneum (Fig. III.14.6).
III.14.5.2 Pink Nevus
Histopathologically, melanocytes in pink nevi do not contain pigment and are typically ar- ranged in nests at the dermo-epidermal junc- tion and in the upper dermis (compound ne- vus).
III.14.5.3 White Nevus
Histopathology reveals an increased number of atypical melanocytes with hyperchromatic and pleomorphic nuclei, arranged as solitary units and in nests, mainly at the dermo-epidermal junction and the papillary dermis. Stromal
changes may show focally lamellar fibrosis, but no evidence of inflammatory infiltrates, accu- mulation of melanophages, or increase of blood vessels. Staining with Fontana-Masson does not reveal pigmented granules. Immunohistochem- ical staining for S-100 protein shows strong positivity of all cells, whereas HMB-45 may be positive only in scattered melanocytes.
III.14.6 Management III.14.6.1 Black Nevus
The stereotypical black nevus does not need to be excised. Attention should be focused not to miss subtle clues pointing to a more ominous diagnosis. The novice dermoscopist might con- sider excising a solitary black nevus or one of multiple lesions to confirm the diagnosis. With experience, this will no longer be necessary.
Baseline gross and digital dermoscopic images can be used to follow these patients.
III.14.6.2 Pink Nevus
The index of suspicion should always be in- creased for potentially high-risk pathology when a pink lesion is seen. There is no general management rule for these nevi; it depends strongly on the experience of the clinician. In
Fig. III.14.6. Histopathology of a black nevus reveals an increased number of melanocytes arranged as mainly solitary units at the dermo-epidermal junction. Note the overlying pigmented parakeratosis corresponding to the clinico-dermoscopic feature of the black lamella
146 I. Zalaudek, B. Leinweber, R. Johr
III.14
cases of a single lesion and/or history of change, excision to rule out melanoma should be per- formed.
III.14.6.3 White Nevus
The diagnosis of this peculiar nevus is based on its histopathological features, since the clinical diagnosis is often difficult. Patients with this type of nevus seem to be at higher risk for mela- noma development and should be managed similar to patients with a dysplastic nevus syn- drome (i.e., complete skin examinations and regular follow-up visits every 6–12 months).
C
Core Messages
■ Black, pink, or white nevi represent a sub-group of melanocytic lesions that differ in color from the ubiquitous brown melanocytic nevus.
■ Their management should be individu- alized for each patient.
■ A good clinical-dermoscopic correla- tion is essential and as much of the clinical picture should be put together before deciding on the disposition of a lesion.
References
1. Cohen LM, Bennion SD, Johnson TW, Golitz LE.
Hypermelanotic nevus: clinical, histopathologic, and ultrastructural features in 316 cases. Am J Der- matopathol 1997; 19:23–30
2. Friedmann RJ, Heilman ED, Rigel DS, Kopf AW, et al. Clinical features of dysplastic melanocytic nevi.
Dermatol Clin 1985; 9:239–249
3. Johr RH. Pink lesions. Clin Dermatol 2002;20:289–
4. Zalaudek I, Hofmann-Wellenhof R, Cerroni L, Kerl 296 H. “White” dysplastic melanocytic naevi. Lancet 2002; 359:1999–2000
5. Hofmann-Wellenhof R, Blum A, Wolf IH, Piccolo D, Kerl H, Garbe C, Soyer HP. Dermoscopic classifica- tion of atypical melanocytic nevi (Clark nevi). Arch Dermatol 2001;13:1575–1580
6. Argenziano G, Zalaudek I, Corona R, Sera F, Cicale L, Petrillo G, Ruocco E, Hofmann-Wellenhof R, Soy- er HP. Vascular structures in skin tumors: a dermos- copy study. Arch Dermatol 2004;140:1485–1489 7. Ferrari A, Bono A, Baldi M, Collini P, Casanova M,
Pennacchioli E, Terenziani M, Marcon I, Santinami M, Bartoli C. Does melanoma behave differently in younger children than in adults? A retrospective study of 33 cases of childhood melanoma from a single institution. Pediatrics 2005;115:649–654
