Observational study on the mitotic rate and other prognostic factors in cutaneous primary melanoma arising from naevi and from melanoma de novo. (14th February 2014)

• Record Type: Journal Article
• Authors: Betti, R.; Santambrogio, R.; Cerri, A.; Vergani, R.; Moneghini, L.; Menni, S.
• Is Part Of: Journal of the European Academy of Dermatology and Venereology. Volume 28:Number 12(2014:Dec.)
• Page Start: 1738
• Page End: 1741
• Publication Date: 2014-02-14
• Subjects: Dermatology -- Periodicals; Sexually transmitted diseases -- Periodicals; 616.5
• DOI: 10.1111/jdv.12395
• Languages: English
• ISSNs: 0926-9959

Abstract

<abstract abstract-type="main" id="jdv12395-abs-0001"> <title>Abstract</title> <sec id="jdv12395-sec-0001" sec-type="section"> <title>Background</title> <p>Melanomas can arise from naevi or appear <italic>de novo</italic>. The frequency or the effect of their origin on prognosis is still debated. Mitotic rate (MR) and ulceration of melanomas have been proposed as further new prognostic indexes.</p> </sec> <sec id="jdv12395-sec-0002" sec-type="section"> <title>Aim</title> <p>To determine the different prognostic factors in melanomas <italic>de novo</italic> and melanomas from pre‐existing naevi and whether these two melanoma groups have different MR or presence of ulceration.</p> </sec> <sec id="jdv12395-sec-0003" sec-type="section"> <title>Methods</title> <p>All patients with confirmed primary melanomas observed in our clinic from 1996 to July 2013 were included. The distinction between the two groups of melanomas was histologically based. We compared Breslow's thickness, the number of mitosis/mm<sup>2</sup> and the presence of ulceration between the naevus‐associated melanoma and <italic>de novo</italic> melanoma group.</p> </sec> <sec id="jdv12395-sec-0004" sec-type="section"> <title>Results</title> <p>Of the 873 melanomas, 626 (71.8%) have a <italic>de novo</italic> melanoma, 247 (28.2%) a naevus‐associated melanoma. Breslow's thickness was not significantly different in the two groups (0.77 ± 1.47 mm vs. 0.59 ± 1.35 mm). The number of patients with presence of ulceration and MR ≥1 mitosis/mm<sup>2</sup> was not significantly different in the two groups (19.6% vs. 16.3%). In thicker melanomas (Breslow's thickness ≥ 1 mm), the number of patients with ≥6 mitosis/mm<sup>2</sup> was significantly higher (26.6% vs. 7.9%; <italic>P</italic> < 0.05) in the <italic>de novo</italic> melanoma group.</p> </sec> <sec id="jdv12395-sec-0005" sec-type="section"> <title>Conclusions</title> <p>When mitosis ≥ 1 mm/mm<sup>2</sup>, the results obtained do not show a better or worse prognosis based on Breslow's thickness, ulceration and MR in melanomas associated with naevus vs. melanomas <italic>de novo</italic>. When ≥6 mitosis/mm<sup>2</sup> are considered, the number of patients in the <italic>de novo</italic> melanoma group with thick melanoma is highly more represented. The debate about the cut‐off value of mitosis ≥1 mm<sup>2</sup> is open.</p> </sec> </abstract>