Clinics in Dermatology (2014) 32, 88–93
Flat pigmented macules on sun-damaged skin of the head/ neck: Junctional nevus, atypical lentiginous nevus, or melanoma in situ? Iris Zalaudek, MD a,b,⁎, Carlo Cota, MD c , Gerardo Ferrara, MD d , Elvira Moscarella, MD a , Pascale Guitera, MD, PhD e , Caterina Longo, MD a , Simonetta Piana, MD f , Giuseppe Argenziano, MD a a
Skin Cancer Unit, Arcispedale Santa Maria Nuova, Istituto di Ricovero e Cura a Carattere Scientifico, Viale Risorgimento 80, 42100 Reggio Emilia, Italy b Department of Dermatology, Medical University of Graz, Auenbruggerplatz 8, 8036 Graz, Austria c Department of Dermatopathology, San Gallicano Dermatologic Institute, Via Elio Chianesi 53, 00144 Rome, Italy d Pathologic Anatomy Unit, Gaetano Rummo General Hospital, Camperdown 2050, New South Wales, Australia e Melanoma Institute Australia, The University of Sydney and and Sydney Melanoma Diagnostic Centre, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia f Unit of Anatomic Pathology, Arcispedale Santa Maria Nuova, Istituto di Ricovero e Cura a Carattere Scientifico, Viale Risorgimento 80, 42100 Reggio Emilia, Italy
Abstract The clinical recognition of lentigo maligna (LM) in the mottled chronic sun-damaged skin can be challenging, because it shares many clinical features with other pigmented macules that commonly arise on sun-damaged skin. These include solar lentigo, flat seborrheic keratosis, and pigmented actinic keratosis, but almost never “nevus.” The reason nevus is not included in the differential diagnosis of LM can be explained by the fact that the stereotypical appearance of a facial nevus differs remarkably from that of an LM. Facial nevi in adults are usually nodular, dome-shaped, well-defined, and hypopigmented (ie, intradermal nevus of the Miescher type), whereas LM typically appears as a flat, ill-defined, and pigmented macule. Although this concept based on clinical observations sounds reasonable, clinicians apply it often only unconsciously and accept a given histopathologic diagnosis of a “junctional or lentiginous nevus” of a flat pigmented facial macule without the necessary criticism about its clinicopathologic validity. © 2014 Published by Elsevier Inc.
General background The term lentigo maligna (LM) refers to melanoma in situ arising on chronically sun-damaged skin. The most important risk factor for LM is cumulative sun exposure and, accordingly, it most commonly occurs on the head/neck area. Patients with LM are generally older than 40 years, with a mean age of 65 years. The peak incidence occurs in the ⁎ Corresponding author. Tel.: +43 676 33 282 69; fax: +39 069 762 5822. E-mail address: [email protected] (I. Zalaudek). 0738-081X/$ – see front matter © 2014 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.clindermatol.2013.05.029
seventh to eighth decades of life, with a slight female preponderance. Although cases of LM in association with a preexisting nevus have been reported, the great majority of them will arise de novo.1
Clinical features and biology LM belongs to the group of very slow-growing melanomas and, accordingly, can remain for years, if not
Facial melanoma in situ decades, in a horizontal growth phase before invading the dermis. 2–6 Initial lesions may appear as a clinically inconspicuous, small, flat, and uniform pigmented macule, acquiring over a variable time worrisome clinical features such as large size, irregular and ill-defined border, or color irregularity (Figure 1). This also explains why LM has been previously defined as premalignant or precursor of melanoma; currently, there is no doubt that LM represents melanoma in situ in all its aspects including morphology, biology, and genetics. Accordingly, LM should be diagnosed and treated at the earliest stage.
Clinical differential diagnosis The clinical recognition of LM in the mottled, chronic sun-damaged skin can be challenging because it shares many clinical features with other pigmented macules that commonly arise on sun-damaged skin. These include solar lentigo, flat seborrheic keratosis, and pigmented actinic keratosis (Figure 2).7,8 It is remarkable that the list of differentials almost never includes a “nevus” but refers exclusively to nonmelanocytic lesions. The reason a nevus is not included in the differential diagnosis of LM can be explained by the common clinical evidence that nevus on the head/neck in an adult appears as a dome-shaped, well-defined, often hypopigmented nodule (ie, intradermal nevus of the Miescher type; Figure 3).9–13 In other words, the stereotypical clinical appearance of a head/neck nevus differs remarkably from that of an LM (Figure 4); as a consequence, nevus is not considered in the clinical differential diagnosis of flat, facial pigmented macule on sun-damaged skin. Although this concept based on epidemiologic and clinical data sounds simple and logical, it is all too often only unconsciously applied in clinical practice and, accord-
Fig. 1
89 ingly, a given histopathologic diagnosis of a “junctional or lentiginous nevus” of a flat pigmented macule of the head/ neck of an elderly patient is accepted without sufficient criticism about its clinicopathologic validity.
Limitations of histopathology The lack of criticism might be related to the fact that histopathology is undoubtedly the gold standard in the diagnosis of melanocytic and nonmelanocytic skin tumors. Although this is true in the diagnosis of equivocal lesions selected for biopsy, it must be acknowledged that histopathology cannot be regarded as the gold standard in the diagnosis of the wide range of benign lesions that are not routinely excised. In this setting, the clinical knowledge about the prevalence and morphologic appearance of common benign lesions such as facial dermal nevi outweighs by far any histopathologic experience. Pathologists are continuously faced with the decision, often based on a small piece of skin, whether a biopsied lesion is benign or malignant. The diagnosis of LM is particularly challenging because the “classical” pattern characterized by single-cell (basilar) predominance and deep intraepithelial adnexal extension is present in only a minority of cases; significant dysplastic (Clark) nevus-like features are present in more than 50% of cases14; Reed nevus-like features are also possible.14 Further problems can be encountered on small biopsy specimens as a consequence of an inaccurate sampling, namely, the discontinuous melanocytic proliferation (skip areas) and the occurrence of a “collision” neoplasm. The detection of cytologically atypical melanocytes is theoretically helpful; it is, however, very difficult (and highly subjective) to distinguish atypical melanocytes of LM from the pleomorphic, atypical melanocytes in actinically damaged skin.15–18
Clinical aspects in the progression of melanoma on chronically sun-damaged skin of the head/neck.
90
I. Zalaudek et al.
Fig. 2 Lentigo maligna, pigmented actinic keratosis, and flat seborrheic keratosis present clinically as flat, pigmented macule on chronically sun-damaged skin of the head/neck.
It, therefore, does not come as a surprise that the concept of junctional or atypical lentiginous nevus of the face of elderly and its role as potential precursor originate from histopathology.19,20
Importance of a good clinicopathologic correlation in the management of junctional melanocytic proliferations of the head/neck In light of the difficulties in the histopathologic diagnosis of early LM, it appears particularly to be the clinician’s responsibility and obligation to critically review a given diagnosis of a junctional or atypical lentiginous nevus and to correlate such diagnosis with the clinical context of the patient.
Fig. 3
The importance of a critical clinicopathologic correlation in the diagnosis of facial LM is best supported by the following case. A 54 year-old woman sought dermatologic consultation because of a newly developing pigmentation arising around a surgical scar located on the neck. On clinical examination, a 2.5-cm, reddish to light brown, irregularly defined macule was seen at the lateral border of a 5-cm scar on her throat (Figure 5). Her medical records revealed a complete excision of a junctional nevus 3 years ago and the re-excision of a recurrent junctional nevus 1 year ago. Based on the medical history and the clinical picture of a large, twice recurring pigmentation, a diagnosis of recurrent LM was made and the lesion was excised for histopathologic diagnosis. This time, a diagnosis of LM was made histopathologically (Figure 6). On additional review of the original slide from 3 years ago, the original diagnosis of “junctional” nevus was revised as melanoma in situ (Figure 7).
Stereotypical appearance of nevi on chronically sun-damaged skin of the head/neck.
Facial melanoma in situ
91
Fig. 4 Lentigo maligna presents as flat, pigmented macule (left), whereas nevi chronically sun-damaged skin of the head/neck of adults are nodular and hypopigmented. This explains why nevus is not included in the differential diagnosis of flat, pigmented macules of the head/neck area.
The problem related to this case is that several clinical features were not critically questioned in light of a given histopathologic diagnosis of a benign junctional nevus: 1. Several studies support that nevi of the head/neck of persons older than 60 years are nodular and reveal histopathologic features of a benign intradermal nevus of the Miescher type. The presented lesion was diagnosed as a junctional nevus, which is unusual for the location of the lesion and the age of the patient.11–13 2. Clinically, junctional nevi are generally small and do exceed more than 6 mm in diameter.13 A surgical scar, even if considering the re-excision, of 5 cm points toward a lesion exceeding by far more than
Fig. 5 Clinical overview and close-up (insert) of recurrent lentigo maligna, initially underdiagnosed as junctional nevus. A faint redlight brown pigmentation at the lateral proportion of the surgical scar is seen.
6 mm. The large size of the lesion is suggestive of growth; yet, growing melanocytic lesions are rather unusual after the age of 50 years and should always raise the suspicion of melanoma.21–23 3. Recurrent nevi occur usually a few weeks after partial biopsy of a dermal or compound nevus but are seldom reported after partial biopsy of a junctional nevus.24–26 Supplementary, benign nevi recur usually only a few weeks after incomplete biopsy, and repigmentation occurs within the scar. Instead, recurrent melanoma tends to recur often months after incomplete biopsy and regrows more commonly lateral to the scar.25–27
Fig. 6 Histopathology of the lesion as shown in Figure 5 is characterized by increased single and nested atypical melanocytes irregularly distributed along the basal membrane; in the middle of the lesion, a band of cicatricial tissue with inflammation is present in the dermis. High magnification (inset) shows an atypical nest and upward migration of single atypical melanocytes into the epidermis.
92
I. Zalaudek et al. Finally, photographic documentation of lesions scheduled for biopsy and its review after receiving the histopathologic diagnosis will facilitate the clinicopathologic correlation, despite improving the clinical skills.
References
Fig. 7 Histopathology of the original excision of the lesion shown in Figure 5, which was initially diagnosed as junctional nevus. Histopathology shows an atypical junctional proliferation of melanocytes mainly arranged in single units associated with asymmetrically distributed lymphocytic infiltrate.
Teaching points and recommendations for the clinician Nevi on the sun-damaged skin of the head/neck are hypopigmented and nodular, whereas LM represents a flat, ill-defined, pigmented macule (Figure 8). Histopathologic underestimation of LM as benign junctional proliferation is a reality, and clinicians should be aware of this risk. To avoid misdiagnosis or delayed diagnosis of melanoma, clinicians should always question a given histopathologic diagnosis of a junctional nevus, dysplastic nevus, or atypical lentiginous nevus from sun-damaged skin of the head/neck area that underwent a biopsy. Any biopsy specimen destined for the pathologist should always be accompanied by the clinical information of sex, age, location, and leading clinical differential diagnosis.
Fig. 8 Stereotypical appearance of melanocytic tumors on the sun-damaged skin of the head and neck: The flat and pigmented macule is melanoma in situ (arrow), whereas the hypopigmented nodule is an intradermal nevus (square).
1. Reed JA, Shea CR. Lentigo maligna: melanoma in situ on chronically sun-damaged skin. Arch Pathol Lab Med. 2011;135:838-841. 2. Lipsker D, Engel F, Cribier B, Velten M, Hedelin G. Trends in melanoma epidemiology suggest three different types of melanoma. Br J Dermatol. 2007;157:338-343. 3. Argenziano G, Zalaudek I, Ferrara G. Fast-growing and slow-growing melanomas. Arch Dermatol. 2007;143:802-803. 4. Ferrara G, Ligrone L, Zalaudek I, Mordente I, Argenziano G. Lentigo maligna in a young adult. Dermatology. 2008;217:66-68. 5. Zalaudek I, Marghoob AA, Scope A, et al. Three roots of melanoma. Arch Dermatol. 2008;144:1375-1379. 6. Schiffner R, Perusquia AM, Stolz W. One-year follow-up of a lentigo maligna: first dermoscopic signs of growth. Br J Dermatol. 2004;151: 1087-1089. 7. Stolz W, Schiffner R, Burgdorf WH. Dermatoscopy for facial pigmented skin lesions. Clin Dermatol. 2002;20:276-278. 8. Witt C, Krengel S. Clinical and epidemiological aspects of subtypes of melanocytic nevi (Flat nevi, Miescher nevi, Unna nevi). Dermatol Online J. 2010;16:1. 9. Ackerman AB, Magana-Garcia M. Naming acquired melanocytic nevi. Unna’s, Miescher’s, Spitz’s Clark’s. Am J Dermatopathol. 1990;12: 193-209. 10. Yus ES, del Cerro M, Simón RS, Herrera M, Rueda M. Unna’s and Miescher’s nevi: two different types of intradermal nevus: hypothesis concerning their histogenesis. Am J Dermatopathol. 2007;29: 141-151. 11. Piliouras P, Gilmore S, Wurm EM, Soyer HP, Zalaudek I. New insights in naevogenesis: number, distribution and dermoscopic patterns of naevi in the elderly. Australas J Dermatol. 2011;52:254-258. 12. Lund HZ, Stobbe GD. The natural history of the pigmented nevus; factors of age and anatomic location. Am J Pathol 1949;25:1117–1155, incl 4 pl. 13. Schmoeckel C. Classification of melanocytic nevi: do nodular and flat nevi develop differently? Am J Dermatopathol. 1997;19:31-34. 14. Farinaz F, Egbert B, Swetter SM. Histological similarities between lentigo maligna and dysplastic nevus: importance of clinicopathologic distinction. J Cutan Pathol. 2005;32:405-412. 15. Massi G, LeBoit PE, eds. Histopathological diagnosis of nevi and melanoma. Darmstadt: Springer; 2004: 401-408. 16. Weyers W, Bonczkowitz M, Weyers I, Bittinger A, Schill WB. Melanoma in situ versus melanocytic hyperplasia in sun-damaged skin. Assessment of the significance of histopathologic criteria for differential diagnosis. Am J Dermatopathol. 1996;18:560-566. 17. Hendi A, Wada DA, Jacobs MA, et al. Melanocytes in nonlesional sunexposed skin: a multicenter comparative study. J Am Acad Dermatol. 2011;65:1186-1193. 18. Hendi A, Brodland DG, Zitelli JA. Melanocytes in long-standing sunexposed skin: quantitative analysis using the MART-1 immunostain. Arch Dermatol. 2006;142:871-876. 19. Kossard S. Atypical lentiginous junctional naevi of the elderly and melanoma. Australas J Dermatol. 2002;43:93-101. 20. Kossard S, Commens C, Symons M, Doyle J. Lentinginous dysplastic naevi in the elderly: a potential precursor for malignant melanoma. Australas J Dermatol. 1991;32:27-37. 21. Zalaudek I, Schmid K, Marghoob AA, et al. Frequency of dermoscopic nevus subtypes by age and body site: a cross-sectional study. Arch Dermatol. 2011;147:663-670.
Facial melanoma in situ 22. Kittler H, Seltenheim M, Dawid M, Pehamberger H, Wolff K, Binder M. Frequency and characteristics of enlarging common melanocytic nevi. Arch Dermatol. 2000;136:316-320. 23. Zalaudek I, Catricalà C, Moscarella E, Argenziano G. What dermoscopy tells us about nevogenesis. J Dermatol. 2011;38: 16-24. 24. Sommer LL, Barcia SM, Clarke LE, Helm KF. Persistent melanocytic nevi: a review and analysis of 205 cases. J Cutan Pathol. 2011;38: 503-507.
93 25. Marghoob AA, Changchien L, DeFazio J, et al. The most common challenges in melanoma diagnosis and how to avoid them. Australas J Dermatol. 2009;50:1-13. quiz 14–15. 26. Longo C, Moscarella E, Pepe P, et al. Confocal microscopy of recurrent naevi and recurrent melanomas: a retrospective morphological study. Br J Dermatol. 2011;165:61-68. 27. Zalaudek I, Horn M, Richtig E, et al. Local recurrence in melanoma in situ: influence of sex, age, site of involvement and therapeutic modalities. Br J Dermatol. 2003;148:703-708.
Flat pigmented macules on sun-damaged skin of the head/ neck: Junctional nevus, atypical lentiginous nevus, or melanoma in situ? Iris Zalaudek, MD a,b,⁎, Carlo Cota, MD c , Gerardo Ferrara, MD d , Elvira Moscarella, MD a , Pascale Guitera, MD, PhD e , Caterina Longo, MD a , Simonetta Piana, MD f , Giuseppe Argenziano, MD a a
Skin Cancer Unit, Arcispedale Santa Maria Nuova, Istituto di Ricovero e Cura a Carattere Scientifico, Viale Risorgimento 80, 42100 Reggio Emilia, Italy b Department of Dermatology, Medical University of Graz, Auenbruggerplatz 8, 8036 Graz, Austria c Department of Dermatopathology, San Gallicano Dermatologic Institute, Via Elio Chianesi 53, 00144 Rome, Italy d Pathologic Anatomy Unit, Gaetano Rummo General Hospital, Camperdown 2050, New South Wales, Australia e Melanoma Institute Australia, The University of Sydney and and Sydney Melanoma Diagnostic Centre, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia f Unit of Anatomic Pathology, Arcispedale Santa Maria Nuova, Istituto di Ricovero e Cura a Carattere Scientifico, Viale Risorgimento 80, 42100 Reggio Emilia, Italy
Abstract The clinical recognition of lentigo maligna (LM) in the mottled chronic sun-damaged skin can be challenging, because it shares many clinical features with other pigmented macules that commonly arise on sun-damaged skin. These include solar lentigo, flat seborrheic keratosis, and pigmented actinic keratosis, but almost never “nevus.” The reason nevus is not included in the differential diagnosis of LM can be explained by the fact that the stereotypical appearance of a facial nevus differs remarkably from that of an LM. Facial nevi in adults are usually nodular, dome-shaped, well-defined, and hypopigmented (ie, intradermal nevus of the Miescher type), whereas LM typically appears as a flat, ill-defined, and pigmented macule. Although this concept based on clinical observations sounds reasonable, clinicians apply it often only unconsciously and accept a given histopathologic diagnosis of a “junctional or lentiginous nevus” of a flat pigmented facial macule without the necessary criticism about its clinicopathologic validity. © 2014 Published by Elsevier Inc.
General background The term lentigo maligna (LM) refers to melanoma in situ arising on chronically sun-damaged skin. The most important risk factor for LM is cumulative sun exposure and, accordingly, it most commonly occurs on the head/neck area. Patients with LM are generally older than 40 years, with a mean age of 65 years. The peak incidence occurs in the ⁎ Corresponding author. Tel.: +43 676 33 282 69; fax: +39 069 762 5822. E-mail address: [email protected] (I. Zalaudek). 0738-081X/$ – see front matter © 2014 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.clindermatol.2013.05.029
seventh to eighth decades of life, with a slight female preponderance. Although cases of LM in association with a preexisting nevus have been reported, the great majority of them will arise de novo.1
Clinical features and biology LM belongs to the group of very slow-growing melanomas and, accordingly, can remain for years, if not
Facial melanoma in situ decades, in a horizontal growth phase before invading the dermis. 2–6 Initial lesions may appear as a clinically inconspicuous, small, flat, and uniform pigmented macule, acquiring over a variable time worrisome clinical features such as large size, irregular and ill-defined border, or color irregularity (Figure 1). This also explains why LM has been previously defined as premalignant or precursor of melanoma; currently, there is no doubt that LM represents melanoma in situ in all its aspects including morphology, biology, and genetics. Accordingly, LM should be diagnosed and treated at the earliest stage.
Clinical differential diagnosis The clinical recognition of LM in the mottled, chronic sun-damaged skin can be challenging because it shares many clinical features with other pigmented macules that commonly arise on sun-damaged skin. These include solar lentigo, flat seborrheic keratosis, and pigmented actinic keratosis (Figure 2).7,8 It is remarkable that the list of differentials almost never includes a “nevus” but refers exclusively to nonmelanocytic lesions. The reason a nevus is not included in the differential diagnosis of LM can be explained by the common clinical evidence that nevus on the head/neck in an adult appears as a dome-shaped, well-defined, often hypopigmented nodule (ie, intradermal nevus of the Miescher type; Figure 3).9–13 In other words, the stereotypical clinical appearance of a head/neck nevus differs remarkably from that of an LM (Figure 4); as a consequence, nevus is not considered in the clinical differential diagnosis of flat, facial pigmented macule on sun-damaged skin. Although this concept based on epidemiologic and clinical data sounds simple and logical, it is all too often only unconsciously applied in clinical practice and, accord-
Fig. 1
89 ingly, a given histopathologic diagnosis of a “junctional or lentiginous nevus” of a flat pigmented macule of the head/ neck of an elderly patient is accepted without sufficient criticism about its clinicopathologic validity.
Limitations of histopathology The lack of criticism might be related to the fact that histopathology is undoubtedly the gold standard in the diagnosis of melanocytic and nonmelanocytic skin tumors. Although this is true in the diagnosis of equivocal lesions selected for biopsy, it must be acknowledged that histopathology cannot be regarded as the gold standard in the diagnosis of the wide range of benign lesions that are not routinely excised. In this setting, the clinical knowledge about the prevalence and morphologic appearance of common benign lesions such as facial dermal nevi outweighs by far any histopathologic experience. Pathologists are continuously faced with the decision, often based on a small piece of skin, whether a biopsied lesion is benign or malignant. The diagnosis of LM is particularly challenging because the “classical” pattern characterized by single-cell (basilar) predominance and deep intraepithelial adnexal extension is present in only a minority of cases; significant dysplastic (Clark) nevus-like features are present in more than 50% of cases14; Reed nevus-like features are also possible.14 Further problems can be encountered on small biopsy specimens as a consequence of an inaccurate sampling, namely, the discontinuous melanocytic proliferation (skip areas) and the occurrence of a “collision” neoplasm. The detection of cytologically atypical melanocytes is theoretically helpful; it is, however, very difficult (and highly subjective) to distinguish atypical melanocytes of LM from the pleomorphic, atypical melanocytes in actinically damaged skin.15–18
Clinical aspects in the progression of melanoma on chronically sun-damaged skin of the head/neck.
90
I. Zalaudek et al.
Fig. 2 Lentigo maligna, pigmented actinic keratosis, and flat seborrheic keratosis present clinically as flat, pigmented macule on chronically sun-damaged skin of the head/neck.
It, therefore, does not come as a surprise that the concept of junctional or atypical lentiginous nevus of the face of elderly and its role as potential precursor originate from histopathology.19,20
Importance of a good clinicopathologic correlation in the management of junctional melanocytic proliferations of the head/neck In light of the difficulties in the histopathologic diagnosis of early LM, it appears particularly to be the clinician’s responsibility and obligation to critically review a given diagnosis of a junctional or atypical lentiginous nevus and to correlate such diagnosis with the clinical context of the patient.
Fig. 3
The importance of a critical clinicopathologic correlation in the diagnosis of facial LM is best supported by the following case. A 54 year-old woman sought dermatologic consultation because of a newly developing pigmentation arising around a surgical scar located on the neck. On clinical examination, a 2.5-cm, reddish to light brown, irregularly defined macule was seen at the lateral border of a 5-cm scar on her throat (Figure 5). Her medical records revealed a complete excision of a junctional nevus 3 years ago and the re-excision of a recurrent junctional nevus 1 year ago. Based on the medical history and the clinical picture of a large, twice recurring pigmentation, a diagnosis of recurrent LM was made and the lesion was excised for histopathologic diagnosis. This time, a diagnosis of LM was made histopathologically (Figure 6). On additional review of the original slide from 3 years ago, the original diagnosis of “junctional” nevus was revised as melanoma in situ (Figure 7).
Stereotypical appearance of nevi on chronically sun-damaged skin of the head/neck.
Facial melanoma in situ
91
Fig. 4 Lentigo maligna presents as flat, pigmented macule (left), whereas nevi chronically sun-damaged skin of the head/neck of adults are nodular and hypopigmented. This explains why nevus is not included in the differential diagnosis of flat, pigmented macules of the head/neck area.
The problem related to this case is that several clinical features were not critically questioned in light of a given histopathologic diagnosis of a benign junctional nevus: 1. Several studies support that nevi of the head/neck of persons older than 60 years are nodular and reveal histopathologic features of a benign intradermal nevus of the Miescher type. The presented lesion was diagnosed as a junctional nevus, which is unusual for the location of the lesion and the age of the patient.11–13 2. Clinically, junctional nevi are generally small and do exceed more than 6 mm in diameter.13 A surgical scar, even if considering the re-excision, of 5 cm points toward a lesion exceeding by far more than
Fig. 5 Clinical overview and close-up (insert) of recurrent lentigo maligna, initially underdiagnosed as junctional nevus. A faint redlight brown pigmentation at the lateral proportion of the surgical scar is seen.
6 mm. The large size of the lesion is suggestive of growth; yet, growing melanocytic lesions are rather unusual after the age of 50 years and should always raise the suspicion of melanoma.21–23 3. Recurrent nevi occur usually a few weeks after partial biopsy of a dermal or compound nevus but are seldom reported after partial biopsy of a junctional nevus.24–26 Supplementary, benign nevi recur usually only a few weeks after incomplete biopsy, and repigmentation occurs within the scar. Instead, recurrent melanoma tends to recur often months after incomplete biopsy and regrows more commonly lateral to the scar.25–27
Fig. 6 Histopathology of the lesion as shown in Figure 5 is characterized by increased single and nested atypical melanocytes irregularly distributed along the basal membrane; in the middle of the lesion, a band of cicatricial tissue with inflammation is present in the dermis. High magnification (inset) shows an atypical nest and upward migration of single atypical melanocytes into the epidermis.
92
I. Zalaudek et al. Finally, photographic documentation of lesions scheduled for biopsy and its review after receiving the histopathologic diagnosis will facilitate the clinicopathologic correlation, despite improving the clinical skills.
References
Fig. 7 Histopathology of the original excision of the lesion shown in Figure 5, which was initially diagnosed as junctional nevus. Histopathology shows an atypical junctional proliferation of melanocytes mainly arranged in single units associated with asymmetrically distributed lymphocytic infiltrate.
Teaching points and recommendations for the clinician Nevi on the sun-damaged skin of the head/neck are hypopigmented and nodular, whereas LM represents a flat, ill-defined, pigmented macule (Figure 8). Histopathologic underestimation of LM as benign junctional proliferation is a reality, and clinicians should be aware of this risk. To avoid misdiagnosis or delayed diagnosis of melanoma, clinicians should always question a given histopathologic diagnosis of a junctional nevus, dysplastic nevus, or atypical lentiginous nevus from sun-damaged skin of the head/neck area that underwent a biopsy. Any biopsy specimen destined for the pathologist should always be accompanied by the clinical information of sex, age, location, and leading clinical differential diagnosis.
Fig. 8 Stereotypical appearance of melanocytic tumors on the sun-damaged skin of the head and neck: The flat and pigmented macule is melanoma in situ (arrow), whereas the hypopigmented nodule is an intradermal nevus (square).
1. Reed JA, Shea CR. Lentigo maligna: melanoma in situ on chronically sun-damaged skin. Arch Pathol Lab Med. 2011;135:838-841. 2. Lipsker D, Engel F, Cribier B, Velten M, Hedelin G. Trends in melanoma epidemiology suggest three different types of melanoma. Br J Dermatol. 2007;157:338-343. 3. Argenziano G, Zalaudek I, Ferrara G. Fast-growing and slow-growing melanomas. Arch Dermatol. 2007;143:802-803. 4. Ferrara G, Ligrone L, Zalaudek I, Mordente I, Argenziano G. Lentigo maligna in a young adult. Dermatology. 2008;217:66-68. 5. Zalaudek I, Marghoob AA, Scope A, et al. Three roots of melanoma. Arch Dermatol. 2008;144:1375-1379. 6. Schiffner R, Perusquia AM, Stolz W. One-year follow-up of a lentigo maligna: first dermoscopic signs of growth. Br J Dermatol. 2004;151: 1087-1089. 7. Stolz W, Schiffner R, Burgdorf WH. Dermatoscopy for facial pigmented skin lesions. Clin Dermatol. 2002;20:276-278. 8. Witt C, Krengel S. Clinical and epidemiological aspects of subtypes of melanocytic nevi (Flat nevi, Miescher nevi, Unna nevi). Dermatol Online J. 2010;16:1. 9. Ackerman AB, Magana-Garcia M. Naming acquired melanocytic nevi. Unna’s, Miescher’s, Spitz’s Clark’s. Am J Dermatopathol. 1990;12: 193-209. 10. Yus ES, del Cerro M, Simón RS, Herrera M, Rueda M. Unna’s and Miescher’s nevi: two different types of intradermal nevus: hypothesis concerning their histogenesis. Am J Dermatopathol. 2007;29: 141-151. 11. Piliouras P, Gilmore S, Wurm EM, Soyer HP, Zalaudek I. New insights in naevogenesis: number, distribution and dermoscopic patterns of naevi in the elderly. Australas J Dermatol. 2011;52:254-258. 12. Lund HZ, Stobbe GD. The natural history of the pigmented nevus; factors of age and anatomic location. Am J Pathol 1949;25:1117–1155, incl 4 pl. 13. Schmoeckel C. Classification of melanocytic nevi: do nodular and flat nevi develop differently? Am J Dermatopathol. 1997;19:31-34. 14. Farinaz F, Egbert B, Swetter SM. Histological similarities between lentigo maligna and dysplastic nevus: importance of clinicopathologic distinction. J Cutan Pathol. 2005;32:405-412. 15. Massi G, LeBoit PE, eds. Histopathological diagnosis of nevi and melanoma. Darmstadt: Springer; 2004: 401-408. 16. Weyers W, Bonczkowitz M, Weyers I, Bittinger A, Schill WB. Melanoma in situ versus melanocytic hyperplasia in sun-damaged skin. Assessment of the significance of histopathologic criteria for differential diagnosis. Am J Dermatopathol. 1996;18:560-566. 17. Hendi A, Wada DA, Jacobs MA, et al. Melanocytes in nonlesional sunexposed skin: a multicenter comparative study. J Am Acad Dermatol. 2011;65:1186-1193. 18. Hendi A, Brodland DG, Zitelli JA. Melanocytes in long-standing sunexposed skin: quantitative analysis using the MART-1 immunostain. Arch Dermatol. 2006;142:871-876. 19. Kossard S. Atypical lentiginous junctional naevi of the elderly and melanoma. Australas J Dermatol. 2002;43:93-101. 20. Kossard S, Commens C, Symons M, Doyle J. Lentinginous dysplastic naevi in the elderly: a potential precursor for malignant melanoma. Australas J Dermatol. 1991;32:27-37. 21. Zalaudek I, Schmid K, Marghoob AA, et al. Frequency of dermoscopic nevus subtypes by age and body site: a cross-sectional study. Arch Dermatol. 2011;147:663-670.
Facial melanoma in situ 22. Kittler H, Seltenheim M, Dawid M, Pehamberger H, Wolff K, Binder M. Frequency and characteristics of enlarging common melanocytic nevi. Arch Dermatol. 2000;136:316-320. 23. Zalaudek I, Catricalà C, Moscarella E, Argenziano G. What dermoscopy tells us about nevogenesis. J Dermatol. 2011;38: 16-24. 24. Sommer LL, Barcia SM, Clarke LE, Helm KF. Persistent melanocytic nevi: a review and analysis of 205 cases. J Cutan Pathol. 2011;38: 503-507.
93 25. Marghoob AA, Changchien L, DeFazio J, et al. The most common challenges in melanoma diagnosis and how to avoid them. Australas J Dermatol. 2009;50:1-13. quiz 14–15. 26. Longo C, Moscarella E, Pepe P, et al. Confocal microscopy of recurrent naevi and recurrent melanomas: a retrospective morphological study. Br J Dermatol. 2011;165:61-68. 27. Zalaudek I, Horn M, Richtig E, et al. Local recurrence in melanoma in situ: influence of sex, age, site of involvement and therapeutic modalities. Br J Dermatol. 2003;148:703-708.
