Betti R, Santambrogio R, Cerri A, Vergani R, Moneghini L, Menni S
Dermatologic Clinic, Department of Health Sciences, Università degli Studi di Milano, Milan, Italy.
J Eur Acad Dermatol Venereol. 2014 Dec;28(12):1738-41. doi: 10.1111/jdv.12395. Epub 2014 Feb 14.
Melanomas can arise from naevi or appear de novo. 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.
To determine the different prognostic factors in melanomas de novo and melanomas from pre-existing naevi and whether these two melanoma groups have different MR or presence of ulceration.
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(2) and the presence of ulceration between the naevus-associated melanoma and de novo melanoma group.
Of the 873 melanomas, 626 (71.8%) have a de novo 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(2) 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(2) was significantly higher (26.6% vs. 7.9%; P < 0.05) in the de novo melanoma group.
When mitosis ≥ 1 mm/mm(2) , 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 de novo. When ≥6 mitosis/mm(2) are considered, the number of patients in the de novo melanoma group with thick melanoma is highly more represented. The debate about the cut-off value of mitosis ≥1 mm(2) is open.
黑色素瘤可起源于痣或新发。其起源的频率或对预后的影响仍存在争议。黑色素瘤的有丝分裂率（MR）和溃疡已被提出作为新的预后指标。
确定新发黑色素瘤和由既往痣发展而来的黑色素瘤的不同预后因素，以及这两组黑色素瘤的有丝分裂率或溃疡情况是否不同。
纳入1996年至2013年7月在我们诊所观察到的所有确诊原发性黑色素瘤患者。两组黑色素瘤的区分基于组织学。我们比较了痣相关黑色素瘤组和新发黑色素瘤组之间的 Breslow厚度、每平方毫米有丝分裂数以及溃疡情况。
在873例黑色素瘤中，626例（71.8%）为新发黑色素瘤，247例（28.2%）为痣相关黑色素瘤。两组的 Breslow厚度无显著差异（0.77±1.47毫米对0.59±1.35毫米）。两组中存在溃疡且有丝分裂率≥1个/平方毫米的患者数量无显著差异（19.6%对16.3%）。在较厚的黑色素瘤（Breslow厚度≥1毫米）中，新发黑色素瘤组中每平方毫米有丝分裂数≥6个的患者数量显著更高（26.6%对7.9%；P<0.05）。
当有丝分裂率≥1个/平方毫米时，基于 Breslow厚度、溃疡和有丝分裂率，痣相关黑色素瘤与新发黑色素瘤的预后结果并无优劣之分。当考虑有丝分裂率≥6个/平方毫米时，新发黑色素瘤组中厚黑色素瘤患者的数量占比更高。关于有丝分裂率≥1个/平方毫米的临界值的争论仍在继续。
