Proliferative nodules in congenital melanocytic nevi：a clinicopathological analysis of eight cases
10.3760/cma.j.issn.0529-5807.2014.09.008
- VernacularTitle:先天性痣伴增生性结节的临床病理分析
- Author:
Yunyi KONG
1
;
Bo DAI
;
Xu CAI
;
Jingjing DENG
;
Jincheng KONG
Author Information
1. 200032,复旦大学上海医学院肿瘤学系 复旦大学附属肿瘤医院病理科
- Keywords:
Nevus;
Skin diseases;
Immunohistochemistry;
Diagnosis,differential
- From:
Chinese Journal of Pathology
2014;(9):609-612
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the clinicopathologic features , differential diagnosis and prognosis of proliferative nodules ( PNs) in congenital melanocytic nevi ( CMN).Methods Histopathologic evaluation and immunohistochemical study by EnVision method were carried out in 8 cases of PNs in CMN.The clinical information and follow-up data were analyzed.Results The age of patients ranged from 1 to 54 years ( mean 27.6 years).Tumors were located on face (3 cases), on back (2 cases), upper extremities (2 cases) and lower extremities(1 case).Microscopically, PNs with expansile growth were observed in 8 cases of CMN.Melanocytes in PNs show variable pleomorphism with a mitotic activity of 0 to 4 per 10 high power fields.Blending of cells with adjacent CMN was noted in 6 cases.According to the morphology of melanocytes in PNs, it was classified into different types including large oval melanocytes ( 4 cases ) , small melanocytes (2 cases) and Spitz-nevus-like forms ( 2 cases ).Immunohistochemically , melanocytes in PNs were consistent with those in adjacent CMN.They were diffusely positive for S-100 protein, but were either negative or focally positive for HMB45.Less than 5% of melanocytes were positive for Ki-67 in 8 cases of PN.Follow-up was available in all cases , ranging from 9 to 82 months.Seven patients with excision of single PN in CMN were alive with no evidence of disease , while 1 patient with multiple PNs in CMN was stable with disease after 62 months follow-up.Conclusions PN is a rare melanocytic lesion arising in CMN.Recognition of its specific histologic features can help to avoid being misdiagnosed as melanoma .Long term follow-up should be recommended in patients with PNs , especially in those with atypical histologic features.Further investigation is needed to elucidate its clinical behavior.
