Clinical Cases in Dermoscopy of Skin Cancers

By Danica Tiodorovic

This book provides a practical guide to the clinical decision-making process used in the management of skin cancers with the use of dermoscopy. Clinical cases are examined to help the reader through the treatment of unusual skin cancers using best practice techniques. A variety of skin conditions are covered, including melanoma, basal cell carcinoma, squamous cell carcinoma, Bowen’s disease and actinic keratosis.

Clinical Cases in Dermoscopy of Skin Cancers highlights evidence-based best practice through its multidisciplinary approach and is an important addition to the literature to help trainees and practicing dermatologists or any healthcare professional who manages these patients.

 

• Language: English
• Publisher: Springer
• Release date: Jan 1, 2020
• ISBN: 9783030294472

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© Springer Nature Switzerland AG 2020

D. TiodorovicClinical Cases in Dermoscopy of Skin CancersClinical Cases in Dermatologyhttps://doi.org/10.1007/978-3-030-29447-2_1

1. A Sixty-Seven-Year-Old Man with a Pigmented Lesion on the Left Temporal Region

Danica Tiodorovic¹  

(1)

Medical Faculty of Nis, Clinical Center of Nis Clinic of Dermatovenerology, University of Nis, Nis, Serbia

Danica Tiodorovic

Keywords

MelanomaLentigo malignaFlat pigmented lesionAngulated lines

History and Clinical

Herein, we present a 67-year-old man with a pigmented lesion on his left temporal region. The patient was retired and spent his life as a teacher of history without any significant professional or sport or other leisure activity that would require sun-exposure. Both the family and personal history of previous skin cancer history were negative. Concerning the history of sunburns, the patient reported several sunburns in the past.

The interesting fact was that the patient did not visit our department for this very lesion, but for a nodular apigmented lesion on his back, which appeared 3 years before that moment, and was gradually growing. Two days earlier, the lesion started bleeding, and the patient got scared and came. The lesion was dermoscopically evaluated and showed the dermoscopic features of nodular basal cell carcinoma, which was afterward excised and pathohistologically verified. As an accurate dermoscopic examination involves examining the entire skin, we initiated a full body examination.

Physical Examination

Numerous solar lentigines and seborrheic keratosis were detected with a few pigmented nevi of regular dermoscopic features. During the examination, apart from solar lentigines on the face, which were mainly located on the forehead, a newly developing lesion was noticed on the patient’s face (Fig. 1.1a). The lesion was irregularly shaped, forming a triangular figure, with 0.9 cm in diameter. It had light brown coloration in the central part of the lesion, while the edges were of a slightly darker brown coloration, located on the left temporal region. The history of the lesion was unreliable as the patient did not know the time of appearance of the lesion.

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Figure 1.1

(a) Flat pigmented macule on the left temporal region of a 67-year old man. (b) Dermoscopic examination showed angulated lines, including discrete rhomboidal structures (black arrow) and zig-zag pattern (white arrow) indicating the diagnosis of lentigo maligna. (c) Atypical melanocytes with continual spreading along epidermodermal boarder without infiltration of dermis. Dermis shows solar elastosis

Diagnosis

Although the clinical appearance did not indicate a suspicious lesion, the dermoscopic evaluation of the lesion revealed dermoscopic features which correlated with the diagnosis of early lentigo maligna. Namely, the fine lines of a zig-zag pattern presented by incompletely formed rhomboidal structures, together with discrete rhomboidal structures were detected. Both described dermoscopic terms encompassed by the term angulated lines are pathognomonic for lentigo maligna (Fig. 1.1b). The lesion was excised by a plastic surgeon, and the diagnosis of lentigo maligna was histopathologically confirmed by the presence of atypical melanocytes with continual spreading along epidermodermal boarder without infiltration of dermis (Fig. 1.1c).

Discussion

Dermoscopy is a non-invasive diagnostic method used for early recognition of melanoma and non-melanoma skin cancers. Clinical examination nowadays implies a dermoscopic examination as an irreplaceable diagnostic tool in everyday routine, so-called dermatologic stethoscope. Depending on dermatologic expertise, dermoscopy can be a powerful tool in the early recognition of skin cancers, both melanoma, and non-melanoma ones [1–4]. In the developmental pathway of dermoscopy, there were a lot of methods such as ABCD rule, Menzies method, and others [5, 6]. However, the patter analysis represents a gold standard in the dermoscopic evaluation of skin lesions. This is because the pattern analysis allows for early detection of suspected lesions based on a single dermoscopic feature, thus allowing the earliest diagnosis of clinically inconspicuous looking skin tumors possible [7].

Although this book is oriented to the resolution of clinical dermoscopy cases, it intends to provide a very brief review of the most important aspects of dermoscopy.

Lentigo maligna (LM) and its invasive form named lentigo maligna melanoma (LMM) are located on the face in the majority of cases. Though there is an extra-facial variant, it is much less frequent [8, 9]. Dermoscopic features of in situ (LM) and an invasive variant of this special type of melanoma (LMM) are caused by special histopathological structures of the facial skin such as closely packed pilosebaceous units and absence of rete ridges. The progression model of lentigo maligna had been previously described and includes: asymmetric pigmented follicles (gray circles within or around the follicular opening), annular-granular pattern (gray dots and globules in between the follicular openings), circle within a circle (gray circle within the hair follicular surrounded by an outer gray to gray-brown circle), pigmented rhomboidal structures (brown to grayish lines or dots forming lines or rhomboids between the follicular openings), darkening at dermoscopic examination (observation on dermoscopic images of the presence of a color, invisible to the naked eye, and darker than all clinically observable shades of brown or gray), target-like pattern (presence of a dark dot in the center of the hair follicle surrounded by a gray circle), increased density of the vascular network (vascular network of higher density within the lesion than in the peripheral skin), red rhomboidal structures (linear vessels occurring in the area separating the hair follicles from the others), obliterated hair follicles (structureless blue-gray areas within the follicular opening), white scar-like areas (white-gray structureless areas in between the follicular openings) [10]. Recently, the new term has been proposed and named angulated lines which encompasses all previously described dermoscopic features such as rhomboidal structures, zig-zag pattern (brown to bluish gray dots and lines arranged in an angulated linear fashion) and polygonal structures (large rhomboidal structures) [11]. Apart from these dermoscopic features, the presence of gray color irrespectively of the associated dermoscopic pattern may represent the only dermoscopic clue for recognition of early LM leading clinicians to perform a biopsy [12].

Understanding the dermoscopic presentation of lentigo maligna is of crucial importance to make an early diagnosis and consequential surgical excision on the one hand, while reducing unnecessary surgical excisions among many mimickers of lentigo maligna such as solar lentigo, seborrhoeic keratosis, pigmented actinic keratoses, and others, on the