1例徽章样真皮树突细胞错构瘤组织病理特征分析

Histopathological features of medallion-like dermal dendrocyte hamartoma in one case

目的探讨1例徽章样真皮树突细胞错构瘤患儿的临床表现及组织病理特征。方法2021年11月广东医科大学附属医院诊治徽章样真皮树突细胞错构瘤患儿1例,男,2岁,以“右臀部褐红色斑块2年”为主诉入院。患儿右臀部可见数片萎缩性斑块,皮损最大约4.0 cm×3.5 cm,形状不规则,呈红褐色,质地坚实,表面光滑,边界较清,部分皮损融合,中部萎缩,轻度压痛。完善体表超声检查和盆腔MRI检查后行手术治疗,术后行组织病理、免疫组织化学检查及COL1A1-PDGFB融合基因、PRDM10断裂基因检查。随访1年观察肿瘤复发情况。结果术前体表超声检查提示血管瘤可能。盆腔MRI检查可见右侧臀部皮下异常信号灶,T_(1)WI低信号、T_(2)WI压脂信号影,增强扫描明显强化,大小约19 mm×10 mm×23 mm,边界清晰,形态规则,考虑肿瘤性病变。全身麻醉下完整切除肿瘤。术后组织病理检查结果显示表皮大致正常,真皮中上层可见大量梭形成纤维细胞带状浸润,梭形肿瘤细胞与表皮平行分布,未累及真皮乳头层,细胞形态较为均一,部分呈胖梭形,异型性不明显,核分裂象少见,肿瘤细胞间可见较多肥大细胞散在分布及扩张的小血管,局部可见梭形细胞向皮下脂肪层浸润,肿瘤区域附属器结构完整,间质胶原化明显;免疫组织化学结果显示CD34、vimentin、CD117肥大细胞阳性,CD31、CD68、S-100、Melan-A、Desmin、SMA、EMA、ERG、SOX-10、STAT-6、h-Caldesmon、Calponin、FⅩⅢa、CK-pan、CD21、CD23阴性,Ki-67≥10%;COL1A1-PDGFB融合基因、PRDM10断裂基因阴性;诊断为徽章样真皮树突细胞错构瘤。随访至2023年1月,未见肿瘤复发。结论徽章样真皮树突细胞错构瘤组织病理特征与良性成纤维细胞肿瘤近似,肿瘤细胞带状浸润,CD34阳性,而对其他血管、肌源性、神经及黑素细胞等标志物均不敏感。

Objective To investigate the clinical manifestations and histopathological features of medallion-like dermal dendrocyte hamartoma in one child.Methods A 2-year-old boy with medallion-like dermal dendrocyte hamartoma was diagnosed and treated in Affiliated Hospital of Guangdong Medical University in November 2021.He was admitted with the chief complaint of maroon plaque in the right buttock for 2 years.Physical examination showed several atrophic plaques on the right buttock,about 4.0 cm×3.5 cm at the largest lesion,irregular in shape,maroon,firm in texture,smooth in surface,clear in border,fusion of some lesions,atrophy in the middle,and mild tenderness.Preoperative body surface ultrasonography and pelvic MRI were performed.Histopathological and immunohistochemical examinations and COL1A1-PDGFB fusion gene and PRDM10 breakage gene examination were performed after operation.He was followed up for 1 year to observe the tumor recurrence.Results Preoperative body surface ultrasonography revealed hemangioma;pelvic MRI showed abnormal subcutaneous signal lesions in the right buttock,low-signal intensity on T_(1)WI and fat signal shadow on T_(2)WI,which were significantly enhanced on enhanced scan,measuring about 19 mm×10 mm×23 mm,with clear boundary and regular shape,considering neoplastic lesions.The results of postoperative histopathological examination showed that the epidermis was approximately normal;a large number of spindle fibroblasts were infiltrated in the middle and upper dermis;spindle tumor cells were distributed in parallel with the epidermis,without involving the papillary dermis;the cell morphology was relatively uniform,some of which showed fat spindle-shaped,atypia was not obvious,and mitotic figures were rare;more mast cells were scattered and dilated small blood vessels were observed between tumor cells,and the spindle cells were infiltrated into the subcutaneous fat layer locally;the adnexa structure of the tumor area was intact,and interstitial collagenization was obvious.The immunohistochemical results showed that CD34,vimentin and CD117 mast cells were positive,CD31,CD68,S-100,Melan-A,Desmin,SMA,EMA,ERG,SOX-10,STAT-6,h-Caldesmon,calponin,FⅩⅢa,CK-pan,CD21 and CD23 were negative,and Ki-67 was≥10%.COL1A1-PDGFB fusion gene and PRDM10 breakage gene were negative.This child was diagnosed with medallion-like dermal dendrocyte hamartoma.The follow-up was done till January 2023,showing no tumor recurrence.Conclusion Medallion-like dermal dendrocyte hamartoma is histopathologically featured by zonal infiltration of tumor cells,CD34 positivity,and insensitive to blood vessels,myogenic,nerves and melanocytes markers,which are similar to those of benign fibroblastic tumors.