10.5826/dpc.1202a60
text/xml
2160-9381
1888
en
Caroline Mills
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
skin cancer
Dermoscopic Features of Amelanotic and Hypomelanotic Melanomas: A Review of 49 Cases
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2022-05-02
2021-07-15
2022-05-02
2022-05-24
e2022060
Dermatol Pract Concept
Caroline Mills
2022/05/02
10.5826/dpc.1202a60
e2022060
St Woolos Hospital, Dermatology department, Newport, United Kingdom
2160-9381
skin cancer
en
e2022060
Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors J Am Acad Dermatol. 2010;63(3):361-374. DOI: 10.1016/j.jaad.2009.11.698. PMID: 20708469..
Dermoscopic Features of Amelanotic and Hypomelanotic Melanomas: A Review of 49 Cases
https://dpcj.org/index.php/dpc/article/download/1888/1595
      Dermoscopic Features of Amelanotic and
   Hypomelanotic Melanomas: a Review of 49 Cases
                      Sarah Dawood1, Alla Altayeb1, Ausama Atwan1, Caroline Mills1


1 St Woolos Hospital, Dermatology department, Newport, United Kingdom.



Key words: Hypomelanotic melanoma, amelanotic melanoma, dermatoscopy, dermoscopy, skin cancer
Citation: Dawood S, Altayeb A, Atwan A, Mills C. Dermoscopic features of Amelanotic and Hypomelanotic Melanomas:
A review of 49 cases. Dermatol Pract Concept. 2022;12(2):e2022060. DOI: https://doi.org/10.5826/dpc.1202a60
Accepted: October 21, 2021; Published: April 2022
Copyright: ©2022 Dawood et al. This is an open-access article distributed under the terms of the Creative Commons
Attribution-NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted
noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing interests: None.
Authorship: All authors have contributed significantly to this publication.
Corresponding author: Dr Sarah Dawood, St Woolos Hospital Dermatology 131 Stow Hill, Newport NP20 4SZ, United Kingdom.
E-mail: sarahamrd@live.co.uk




Introduction                                                             melanoma = 3; lentigomaligna melanoma = 2). The ­remaining
                                                                         3 lesions were in situ AHM. The median Breslow t­hickness
Amelanotic and hypomelanotic melanomas (AHM) represent                   of AHM was higher than pigmented MM (AHM = 1.7
2-8% of all melanomas. They are often diagnosed late due                 mm interquartile range [IQR] = 3.50) versus 0.98 mm
to the lack of a distinctive clinical appearance. As a result,           (IQR = 1.23) for pigmented MM).
AHM is associated with higher mortality compared with pig-                    Short white lines (Figure 1B) and milky-red areas
mented melanomas. It is, therefore, crucial to be aware of the           (­Figure 2B) were the most common dermoscopic findings in
dermoscopic features of such lesions to aid early diagnosis.             our cohort of AHM, observed in 39 lesions (79.6%) and 33
                                                                         lesions (67.3%), respectively. Milky-red areas were present

Case Presentation                                                        in similar frequencies in lesions ≤ 1 mm in thickness (70%)
                                                                         and lesions > 1 mm in thickness (63.9%) (Table 1).
During a 6-year period (2014-2019), a total of 165 ­melanoma                  In our study, 63.3% of AHM had more than one vascu-
cases were diagnosed via our teledermoscopy service, using               lar pattern (Table 1). Dotted, linear, and looped vessels were
Nikon D300S camera and Heine® Delta 20T dermatoscope.                    present in 57.1%, 63.2%, and 63.3% of lesions, respectively.
Of those, 49 cases (29.7%) were AHM, including 27 males                  Dotted vessels were seen in 90% of AHM of < 1mm, com-
and 22 females with a median age of 68 years (range 16-87                pared with 44.4% of AHM of > 1mm.
years). Most AMH were on the upper limbs (20 patients)                        Remnant pigment was present in 27 lesions (55.1%), and
and the trunk (13 patients). The rest were on the lower limbs            present in 70% of lesions ≤ 1mm in thickness and 50% of
(9 patients), and head and neck (7 patients).                            lesions > 1 mm in thickness. Gray granular structures and la-
    Most lesions (n = 46, 83.8%) were invasive AHM                       cunae were less frequently seen, found in 44.9% and 26.5%
(­
 superficial spreading = 27; nodular = 14; desmoplastic                  of lesions, respectively.




Research Letter | Dermatol Pract Concept. 2022;12(2):e2022060                                                                        1
                         Figure 1. (A) Lesion on the forearm of a 46-year-old woman. A confirmed melanoma with
                         Breslow thickness of 1.1 mm. (B) Dermoscopy shows dotted (black arrows) and looped (white
                         arrows) vessels, milky red areas (stars), and white structures (long arrows).




                   Figure 2. (A) Lesion on the lower leg of a 57-year-old woman. A confirmed melanoma with
                   Breslow thickness of 3 mm. (B) Dermoscopy shows irregularly distributed dotted vessels (arrows),
                   a milky red area (star), and a subtle remnant of pigment at the periphery.




Discussion                                                             The incidence of milky-red areas in our study (67.3%) was
                                                                       close to the incidence reported in the literature at 54.5%
Short white lines were the most common finding in our co-              [2,3]. Also, polymorphic vessels, an important distinguishing
hort, seen in 79.6% of cases. This is higher than reported             feature in AHM, were present in over 50% of our AHM cases.
observations at 30.8% [1]. We assume reviewing magnified                   Dotted vessels were present in nearly half of our cases.
images on the monitor contributed to better visualization of           This was similar to the incident reported in the literature
these subtle features.                                                 [1]). Zalaudeket al reported a strong association between



2                                                                          Research Letter | Dermatol Pract Concept. 2022;12(2):e2022060
        Table 1. Dermoscopic features of Amelanotic and hypomelanotic melanoma in our study
                                 AHM ≤ 1mm in thickness          AHM > 1 mm in              AHM in situ             Total AHM
                                        (n = 10)                thickness (n = 36)            (n = 3)                (n = 49)
    Dermoscopic criteria               n               %          n            %            n           %            n         %
 Dotted vessels                        9             90.0         16          44.4          3          100          28        57.1
 Linear vessels                        5             50.0         23          63.9          3          100          31        63.2
 Looped vessels                        3             30.0         26          72.2          2          66.7         31        63.3
 Granular structures                   5             50.0         16          44.4          1          33.3         22        44.9
 Short white lines                     8             80.0         28          77.8          3          100          39        79.6
 Lacuna structures                     3             30.0         10          27.8          0            0          13        26.5
 Milky-red areas                       7             70.0         23          63.9          3          100          33        67.3
 Remnant pigment                       7             70.0         18          50.0          2          66.7         27        55.1
 Polymorphous vessels                  6             60.0         22          61.1          3          100          31        63.2

AHM = amelanotic and hypomelanotic melanomas.



dotted vessels and AHM with Breslow thickness less than 1         References
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We thank the Medical Illustration Department at Aneurin
                                                                      of vascular structures seen with dermoscopy: part I. Melanocytic
Bevan University Health Board for providing the telederma-            skin tumors J Am Acad Dermatol. 2010;63(3):361-374. DOI:
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Research Letter | Dermatol Pract Concept. 2022;12(2):e2022060                                                                        3
