Egan C L, Oliveria S A, Elenitsas R, Hanson J, Halpern A C
Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, USA.
J Am Acad Dermatol. 1998 Dec;39(6):923-32. doi: 10.1016/s0190-9622(98)70264-6.
Large congenital melanocytic nevi may undergo malignant transformation. Few prospective studies have evaluated the incidence of melanoma in large congenital nevi or have described how their phenotypic characteristics change over time.
We attempted to ascertain the incidence of cutaneous melanoma in a cohort of patients with large congenital nevi and to evaluate the frequency and nature of several morphologic changes over time.
Forty-six patients with large congenital nevi were prospectively followed up in our Pigmented Lesion Group. Large congenital nevi were defined as those occurring at birth and comprising 5% body surface area or greater in infants, children, and preadolescents and more than 20 cm in adolescents and adults. Information was obtained on location, satellitosis, changes in color and nodularity, and incidence of melanoma. The most atypical histologic findings from those who underwent biopsy were also noted. Standardized morbidity ratios (SMR) and 5-year cumulative risk were calculated and presented with corresponding 95% confidence intervals (CI).
Twenty-four male and 22 female patients (age range, 7 days to 36.7 years; mean, 8.4 years) with large congenital nevi were followed up prospectively for a total of 335 person-years (range, 0.17 to 17.5 person-years; mean, 7.3 person-years). Two patients (4.3%) experienced 3 cutaneous melanomas that originated in their primary congenital nevi. We found one case of neurocutaneous melanosis. No satellite, extremity, or extracutaneous melanomas were detected. The majority of nevi in our cohort were located on the posterior trunk, were accompanied by multiple satellite congenital nevi, and became lighter over time. In the 27 patients who underwent biopsies, the most atypical histologic findings included melanoma, atypical melanocytic dysplasia, neurocristic dysplasia, atypical neural crest hamartomas, atypical spindle cell tumors, and congenital nevi with dysplasia. The SMR comparing observed-to-expected melanoma incidence was 148 (95% CI 18, 535; P = .0002) indicating a substantially increased risk of melanoma in patients with large congenital nevi. The cumulative 5-year risk of cutaneous melanoma was 5.7% (95% CI 0%, 13.5%).
Our findings are consistent with the previously observed increased risk for the occurrence of cutaneous melanoma in patients with large congenital nevi. Although the number of patients with melanoma in this study is small, our observations and those of previous studies suggest that location and age correlates with melanoma risk. The majority of large congenital nevi are located on the trunk and may undergo several clinical changes as these patients age. Additional prospective studies are needed to gain more insight into the natural history and optimal management of large congenital nevi.
巨大先天性黑素细胞痣可能会发生恶变。很少有前瞻性研究评估巨大先天性黑素细胞痣中黑色素瘤的发病率，或描述其表型特征随时间的变化情况。
我们试图确定一组巨大先天性黑素细胞痣患者中皮肤黑色素瘤的发病率，并评估随着时间推移几种形态学变化的频率和性质。
我们色素沉着病变组对46例巨大先天性黑素细胞痣患者进行了前瞻性随访。巨大先天性黑素细胞痣定义为出生时即存在，在婴儿、儿童和青春期前儿童中占体表面积5%或更大，在青少年和成人中直径超过20 cm。收集了有关痣的位置、卫星灶、颜色和结节性变化以及黑色素瘤发病率的信息。还记录了接受活检患者最不典型的组织学表现。计算标准化发病比（SMR）和5年累积风险，并给出相应的95%置信区间（CI）。
24例男性和22例女性患者（年龄范围7天至36.7岁；平均8.4岁）患有巨大先天性黑素细胞痣，前瞻性随访共335人年（范围0.17至17.5人年；平均7.3人年）。2例患者（4.3%）发生了3例起源于原发性先天性黑素细胞痣的皮肤黑色素瘤。我们发现1例神经皮肤黑素沉着症。未检测到卫星灶、肢体或皮肤外黑色素瘤。我们队列中的大多数痣位于躯干后部，伴有多个卫星先天性黑素细胞痣，且随着时间推移颜色变浅。在接受活检的27例患者中，最不典型的组织学表现包括黑色素瘤、非典型黑素细胞发育异常、神经嵴发育异常、非典型神经嵴错构瘤、非典型梭形细胞瘤和发育异常的先天性黑素细胞痣。观察到的与预期的黑色素瘤发病率比较的SMR为148（95%CI 18，535；P = .0002），表明巨大先天性黑素细胞痣患者发生黑色素瘤的风险显著增加。皮肤黑色素瘤的5年累积风险为5.7%（95%CI 0%，13.5%）。
我们的研究结果与先前观察到的巨大先天性黑素细胞痣患者发生皮肤黑色素瘤的风险增加一致。尽管本研究中黑色素瘤患者数量较少，但我们的观察结果和先前研究表明，位置和年龄与黑色素瘤风险相关。大多数巨大先天性黑素细胞痣位于躯干，随着这些患者年龄增长可能会发生几种临床变化。需要更多的前瞻性研究来更深入了解巨大先天性黑素细胞痣的自然史和最佳治疗方法。
