Dermoscopic features predicting the presence of mitoses in thin melanoma
Introduction
Dermoscopy is a pivotal imaging tool that is currently regarded as gold standard for the preoperative diagnosis of melanoma [1]. In addition, dermoscopy provides a relatively good preoperative assessment of melanoma thickness [2], [3]. More specifically, the presence of an irregular pigment network has been significantly associated to thin melanomas (with a Breslow thickness of less than 0.75 mm), while the present of blue-white veil and atypical vascular patterns have been associated to thicker melanomas (Breslow > 0.75 mm) [2]. Another study assessing the value of dermoscopy to predict sentinel lymph node (SLN) positivity [3] demonstrated that the presence of ulceration and blotches and the absence of pigment network were more likely associated to SLN positivity.
Since the 7th AJCC classification for melanoma introduced the number of mitoses as an additional important prognostic factor for upstaging thin melanoma [4], other studies have analysed their prognostic role in melanoma patients [5]. Yet no studies have been performed to evaluate a possible correlation between certain morphologic features of thin melanoma and the presence of mitoses as measured on histopathology.
The purpose of the current study is to evaluate the correlation between dermoscopic features and the presence of mitoses in a consecutive cohort of thin melanomas.
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Materials and methods
We conducted a retrospective analysis of clinical, dermoscopic and histopathological characteristics of thin melanomas (equal or less than 1 mm in Breslow thickness) consecutively excised at a referral pigmented lesion clinic from 2011 to 2014. Recorded clinical features of the patients included age, sex, date of diagnosis, and body site location of the primary tumour. Two dermatologists (SR and CL) jointly assessed all polarized dermoscopic images in blind for the presence/absence of dermal
Results
Dermoscopic images from 177 histopathologically proven melanomas with Breslow thickness <= 1 mm in 177 patients (119; 67% men) were analysed. Clinical and dermoscopic characteristics of the lesions are listed in Table 1, Table 2, respectively. The majority of lesions (131; 74%) had no mitosis at the histopathological examination, while 46 (36%) had at least 1 mitosis per mm2 (range, 0–11 mitoses). The average Breslow thickness was 0.57 +/− 0.22 (range 0.2–1 mm). Distribution of mitoses according to
Discussion
In the last AJCC staging system, mitotic rate and ulceration have been considered upstaging factors in melanoma thinner than 1 mm, thus influencing the decision to perform SLN biopsy [4]. The invasive technique of sentinel lymph node biopsy (SLNB) has become the standard procedure to detect occult regional node metastasis, and has a value for staging and prognosis in clinically localised primary melanomas [9], [10]. In our study, aimed to identify dermoscopic features that may predict the
References (15)
- et al.
Clinical and dermatoscopic criteria for the preoperative evaluation of cutaneous melanoma thickness
J. Am. Acad. Dermatol.
(1999) - et al.
International Dermoscopy Society Board members Dermoscopy report: proposal for standardization. Results of a consensus meeting of the International Dermoscopy Society
J. Am. Acad. Dermatol.
(2007) - et al.
Accuracy in melanoma detection: a 10-year multicenter survey
J. Am. Acad. Dermatol.
(2012) - et al.
Dermoscopy structures as predictors of sentinel lymph node positivity in cutaneous melanoma
Br. J. Dermatol.
(2015) - et al.
Final version of 2009 AJCC melanoma staging and classification
J. Clin. Oncol.
(2009) - et al.
Mitotic rate correlates with sentinel lymph node status and outcome in cutaneous melanoma greater than 1 millimeter in thickness: a multi-institutional study of 1524 cases
J. Am. Acad. Dermatol.
(2016) - et al.
Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis
J. Eur. Acad. Dermatol. Venereol.
(2016)