Nevi with Particular Pigmentation: Black, Pink, and White Nevus III.14 Iris Zalaudek, Robert Johr, Bernd Leinweber

Chapter III.14 Nevi with Particular Pigmentation: Black, Pink, and White Nevus III.14 Iris Zalaudek, Robert Johr, Bernd Leinweber

Contents III.14.2 Clinical Features III.14.1 Definition...... 142 III.14.2.1 Black Nevus III.14.2 Clinical Features...... 142 III.14.2.1 Black Nevus...... 142 This variant of a benign melanocytic nevus is III.14.2.2 Pink Nevus...... 142 also referred to as a “hypermelanocytic nevus” III.14.2.3 White Nevus ...... 143 or “nevus of midlife.” [1] They appear as black macules often with a subtle touch of brown col- III.14.3 Dermoscopic Criteria...... 143 or at the periphery, 5 mm in size or even smaller III.14.3.1 Black Nevus...... 143 typically located on the trunk and/or extremi- III.14.3.2 Pink Nevus...... 144 ties (Fig. III.14.1). Black nevi vary in number III.14.3.3 White Nevus ...... 144 from a single lesion to more than 50, typically, III.14.4 Relevant Clinical Differential but are not seen only in darker-skinned indi- Diagnosis...... 144 viduals (Fitzpatrick photo-types III and IV) be- III.14.4.1 Black Nevus...... 144 tween the ages of 16 and 30 years (“nevus of III.14.4.2 Pink Nevus...... 144 mid-life”). Because of the intense black color III.14.4.3 White Nevus ...... 145 suggestive of melanoma, they are in the group of III.14.5 Histopathology...... 145 lesions that are referred to as melanoma simula- III.14.5.1 Black Nevus...... 145 tors. A red flag of concern should always be III.14.5.2 Pink Nevus...... 145 raised when a black-pigmented lesion is found. III.14.5.3 White Nevus ...... 145 A single black nevus is more worrisome than multiple lesions. III.14.6 Management ...... 145 Concerns about the diagnosis can be easily III.14.6.1 Black Nevus...... 145 disarmed by its clinical hallmark, the “black la- III.14.6.2 Pink Nevus...... 145 mella.” This represents a removable pigmented III.14.6.3 White Nevus ...... 146 scale located in the center or covering most of References...... 146 the lesion. With tape stripping the black lamella can be removed in most, but not all, lesions dis- playing local dermoscopic criteria. The pigmented scale often is left on the tape, which confirms the banal nature of the lesion.

III.14.2.2 Pink Nevus III.14.1 Definition The worldwide distribution of this variant of a Nevi with particular pigmentation are defined melanocytic nevus varies from country to coun- III.14 herein as benign melanocytic nevi that do not try, and even within regions of a single country. contain significant amounts of brown color. Typically seen in individuals with fair skin type Chapter III.14 Black, Pink, White Nevi Chapter III.14 143 Nevi with Particular Pigmentation: Black, Pink, and White Nevus III.14 Iris Zalaudek, Robert Johr, Bernd Leinweber

Fig. III.14.1. Clinical image of a so-called black nevus Fig. III.14.3. Clinical view of multiple white nevi lo- shows a symmetric dark-colored plaque with a scaly sur- cated on the back. When examined by tangential light, a face. The surface scale is due to the black lamella, which silvery shiny surface with accentuated skin markings can can be easily removed by tape be seen (left)

III.14.2.3 White Nevus

This variant of melanocytic nevus is characterized 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 Fig. III.14.2. Clinical view of a pink nevus reveals a found in individuals with a history of melanoma symmetric pink plaque. Note that on the surrounding and/or have histopathological characteristics of skin pigmented nevi are present. Because this was the dysplastic nevi [4]. only pink lesion seen in this patient, excision was performed and histopathology revealed a benign nevus with mild dysplasia III.14.3 Dermoscopic Criteria III.14.3.1 Black Nevus (Fitzpatrick photo-types I and II) of all ages with other pigmented melanocytic nevi, they Black nevi are characterized by a reticular can be macules and papules (Fig. III.14.2) with pattern, typified by a fine brown pigment net- varying shades of pink color. The papular le- work with regular holes and meshes. Dots can sions are often soft, easily compressible, and at also be seen; however, most of the criteria are times have a single central hair. The number of hidden by the black lamella that appears as dark pink nevi ranges from single to multiple lesions brown or black blotch of featureless color cover- located on any part of the body including the ing most of, if not the entire, lesion (Fig. III.14.4). scalp, where their hidden nature should be un- No high-risk local criteria, such as streaks (typi- covered by a complete skin examination [2, 3]. cal for spitzoid lesions), are ever seen which as- certains the dermoscopic diagnosis [5]. 144 I. Zalaudek, B. Leinweber, R. Johr

Fig. III.14.4. Dermoscopic view of the black nevus as Fig. III.14.5. Dermoscopy of the pink nevus shown in shown in Fig. III.14.1. The central lamella appears as Fig. III.14.2. There is lack of specific structures which a structureless black blotch and covers the underlying would allow the diagnosis of a benign nevus with extreme regular and fine pigment network, which is seen at the confidence. Because this nevus was the only pink lesion border in a patient with a fair skin type and numerous nevi, excision was performed in order to rule out a malignant tumor

III.14.3.2 Pink Nevus III.14.4 Relevant Clinical Differential Diagnosis Pink nevi can be featureless with only shades of III.14.4.1 Black Nevus pink color or feature poor with foci of light- brown color, remnants of fine pigment network, Melanoma is the most important consideration or teleangiectatic vascular structures. The vas- in this clinical setting. Dysplastic nevi and Spitz cular patterns are basically non-specific or may nevi should also be included in the differential reveal dotted, “comma-shaped,” and larger lin- diagnosis. A single lesion is more worrisome ear vessels that can be seen alone or in combina- than multiple symmetrical uniformly pigment- tion (Fig. III.14.5) [6]. The larger arborizing ves- ed round to oval macules or papules with the sels typical of basal cell carcinoma and other typical black lamella. high-risk local dermoscopic criteria seen in pigmented melanocytic nevi are absent. III.14.4.2 Pink Nevus

III.14.3.3 White Nevus A solitary pink macule or papule could be melanocytic or non-melanocytic, benign or malig- White nevi are featureless and reveal only te- nant. Multiple pink lesions, even in their clini- leangiectasias of the dermal plexus shimmering cal features, are typically seen in fair skin types. through the epidermis. 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 III.14 solitary pink lesion could also be amelanotic melanoma. Pediatric patients have a high per- Black, Pink, White Nevi Chapter III.14 145 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 distribution of lesions plus the age and history of the patient. When few in number, consider flat warts as well as seborrheic and lichen planus- Fig. III.14.6. Histopathology of a black nevus reveals like keratosis. With multiple lesions consider an increased number of melanocytes arranged as mainly solitary units at the dermo-epidermal junction. Note the post-inflammatory hypopigmentation, pityria- overlying pigmented parakeratosis corresponding to the sis alba, idiopathic guatte hypomelanosis, hy- clinico-dermoscopic feature of the black lamella popigmented early vitiligo, morphea, lichen sclerosis et atophicus hypopigmented mycosis fungoides, and leprosy [4]. The silvery sheen changes may show focally lamellar fibrosis, but seen with tangential lighting will be a clue to the no evidence of inflammatory infiltrates, accu- diagnosis, which is finally made when the clini- mulation of melanophages, or increase of blood cal picture is put together with histopathology. vessels. Staining with Fontana-Masson does not reveal pigmented granules. Immunohistochem- ical staining for S-100 protein shows strong III.14.5 Histopathology positivity of all cells, whereas HMB-45 may be positive only in scattered melanocytes. III.14.5.1 Black Nevus

Black nevus is characterized by melanocytes ar- III.14.6 Management ranged mainly along the basal layer (junctional nevus) and the finding of pigmented parakera- III.14.6.1 Black Nevus tosis in the stratum corneum (Fig. III.14.6). The stereotypical black nevus does not need to be excised. Attention should be focused not to III.14.5.2 Pink Nevus miss subtle clues pointing to a more ominous diagnosis. The novice dermoscopist might con- Histopathologically, melanocytes in pink nevi sider excising a solitary black nevus or one of do not contain pigment and are typically ar- multiple lesions to confirm the diagnosis. With ranged in nests at the dermo-epidermal junc- experience, this will no longer be necessary. tion and in the upper dermis (compound ne- Baseline gross and digital dermoscopic images vus). can be used to follow these patients.

III.14.5.3 White Nevus III.14.6.2 Pink Nevus Histopathology reveals an increased number of The index of suspicion should always be in- atypical melanocytes with hyperchromatic and creased for potentially high-risk pathology pleomorphic nuclei, arranged as solitary units when a pink lesion is seen. There is no general and in nests, mainly at the dermo-epidermal management rule for these nevi; it depends junction and the papillary dermis. Stromal strongly on the experience of the clinician. In 146 I. Zalaudek, B. Leinweber, R. Johr

cases of a single lesion and/or history of change, References excision to rule out melanoma should be performed. 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 III.14.6.3 White Nevus 2. Friedmann RJ, Heilman ED, Rigel DS, Kopf AW, et al. Clinical features of dysplastic melanocytic nevi. The diagnosis of this peculiar nevus is based on Dermatol Clin 1985; 9:239–249 its histopathological features, since the clinical 3. Johr RH. Pink lesions. Clin Dermatol 2002;20:289– diagnosis is often difficult. Patients with this 296 type of nevus seem to be at higher risk for mela- 4. Zalaudek I, Hofmann-Wellenhof R, Cerroni L, Kerl noma development and should be managed H. “White” dysplastic melanocytic naevi. Lancet 2002; 359:1999–2000 similar to patients with a dysplastic nevus syn- 5. Hofmann-Wellenhof R, Blum A, Wolf IH, Piccolo D, drome (i.e., complete skin examinations and Kerl H, Garbe C, Soyer HP. Dermoscopic classifica- regular follow-up visits every 6–12 months). 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- C Core Messages er HP. Vascular structures in skin tumors: a dermos- ■ Black, pink, or white nevi represent a copy study. Arch Dermatol 2004;140:1485–1489 7. Ferrari A, Bono A, Baldi M, Collini P, Casanova M, sub-group of melanocytic lesions that Pennacchioli E, Terenziani M, Marcon I, Santinami differ in color from the ubiquitous M, Bartoli C. Does melanoma behave differently in brown melanocytic nevus. younger children than in adults? A retrospective ■ Their management should be individu- study of 33 cases of childhood melanoma from a alized for each patient. single institution. Pediatrics 2005;115:649–654 ■ 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.

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