浅表软组织普通淋巴管畸形临床病理及遗传学特征分析

Clinicopathological and genetic characteristics of common lymphatic malformations in superficial soft tissues

目的探讨发生于浅表软组织的单纯性普通淋巴管畸形(common lymphatic malformation,CLM)临床病理学特征、分型和遗传学特征,以及分型与上述特征间的相关性。方法回顾性收集河南省人民医院2019年8月至2022年8月手术切除CLM病例110例,分析临床及病理学信息,并行相关免疫组织化学染色及PIK3CA基因荧光定量PCR检测,随访患者。结果110例患者中男性53例,女性57例,65例(65/110,59.1%)为≤2岁时首次发现,常见于头颈部(41/110,37.3%),102例(102/110,92.7%)为单灶,83例(83/110,75.5%)为肤色肿块,69例(69/110,62.7%)边界不清,10例(10/110,9.1%)为弥漫性大面积重症表现。CLM的分型中,巨囊型52例(52/110,47.3%),微囊型23例(23/110,20.9%),混合型35例(35/110,31.8%)。巨囊型CLM大体上表现为柔软半透明肿块,切面可见大囊腔;镜下由大的不规则扩张管壁组成,管壁较厚,常有不规则平滑肌及淋巴细胞浸润。微囊型CLM大体上表现为皮肤表面疣状突起或半透明水泡,切面多呈细小蜂窝状结构;镜下由圆形或成角的扩张小淋巴管组成,管壁少或无平滑肌。混合型兼具巨囊型和微囊型的形态学表现。免疫组织化学染色显示淋巴管内皮细胞呈LYVE-1、D2-40、PROX1、CD31、VEGFR3阳性,CD34阴性;巨囊型及局灶混合型淋巴管壁呈平滑肌肌动蛋白阳性。13例CLM中8例存在PIK3CA基因点突变。所有患者获随访,24例(24/110,21.8%)术后复发,其多见于混合型,其次为微囊型。结论CLM是异常淋巴管扩张形成的先天性脉管畸形,存在PIK3CA基因突变;不同分型间临床病理学表现存在差异,鉴于微囊型和混合型较易复发,病理诊断应尽可能给予精准分型以指导疾病治疗和预后判断。

Objective To investigate the clinicopathological features,classification,and genetic characteristics of common lymphatic malformation(CLM)in superficial soft tissue.Methods A retrospective study of 110 patients with the diagnosis of CLM at the Henan Province People′s Hospital,China from August 2019 to August 2022 was performed.The clinicopathological features,relevant immunohistochemical(IHC)staining results,and fluorescence quantitative PCR of PIK3CA mutation were analyzed,and patients were followed up.Results Among the 110 CLM patients,there were 53 males and 57 females;65 cases(65/110,59.1%)were first detected when the patients were≤2 years old.The most common location was the head and neck in 41 cases(41/110,37.3%).Clinically,102 cases(102/110,92.7%)were solitary,83 cases(83/110,75.5%)were skin-colored,69 cases(69/110,62.7%)had indistinct borders,and 10 cases(10/110,9.1%)had diffuse and severe macroscopic manifestations.There were 52 macrocystic type(52/110,47.3%),23 microcystic type(23/110,20.9%),and 35 combined type(35/110,31.8%).The macrocystic CLM presented as soft,translucent masses with large cystic cavities on the cut surface,and histologically they were composed of large,irregularly dilated channels that were thicker with irregular smooth muscle and lymphocytic infiltration.Microcystic CLM showed wartlike projections or translucent blisters on the skin,with small honeycomb structures on the cut surface,and histologically consisted of round or angular dilated small lymphatic vessels with little or no smooth muscle.The combined CLM had both macrocystic and microcystic morphologies.IHC staining showed that the lymphatic endothelial cells were positive for LYVE-1,D2-40,PROX1,CD31,and VEGFR3 but negative for CD34;in the macrocystic and combined CLM vessel walls were positive for SMA.Eight of 13 CLM had PIK3CA mutation.All patients were followed up,and 24(24/110,21.8%)had relapses,which more frequently occurred in combined type,followed by microcystic type.Conclusions CLM is a congenital vascular malformation composed of dilated,abnormal lymphatic channels,with PIK3CA mutation.There are significant differences in clinicopathological characteristics among the different types.Since microcystic and combined CLM are prone to recurrence,accurate pathological subtyping is necessary to guide treatment and to predict prognosis.