Objective: To study the utility of immunohistochemistry (IHC) in differential diagnosis between trichoblastoma (TB) and basal cell carcinoma (BCC). Methods: Fifty-eight cases of TB and 40 cases of BCC were collected at Fudan University Shanghai Cancer Center from January 2009 to December 2019 and retrospectively analyzed by IHC for bcl-2, Ber-EP4, CD10, CK20 and Ki-67. Fisher exact test was performed for statistical analysis. Results: Twenty-five (43.1%) TBs and 5 (12.5%) BCCs showed bcl-2 staining in the outermost layer of the epithelial nests, the difference was statistically significant (P<0.01). The proportion of cases with bcl-2 staining>75% of epithelial cells in BCC group was much higher than that in TB group (40% vs. 12.1%; P<0.01). BCC group showed larger proportions with Ber-EP4 staining>75%, 51%-75% of epithelial cells than TB group (12.5% vs. 1.7%, 37.5% vs. 8.6%;P<0.05). Fifty-five (94.8%) TBs demonstrated CD10 expression in the follicular stroma, while only 16 (40.0%) BCCs showed focal or scattered CD10 expression in reactive fibrous stroma (P<0.01). CK20 expression was present in 37 (63.8%) TBs with scattered pattern, but BCCs exhibited no CK20 staining except for only one case (2.5%) showing focal staining (P<0.01). Compared with TB group, the BCC group included more cases with Ki-67 labeling index ≥15% on average and ≥25% in hotspot areas (P<0.05). Conclusion: IHC is helpful in differential diagnosis between TB and BCC. Scattered CK20 staining pattern and stromal CD10 expression support the diagnosis of TB. Bcl-2 staining limited to the outermost layer of the proliferation is more likely to be found in TB. In contrast, Ber-EP4 positivity and higher Ki-67 labeling index tend to be present in BCC.
目的： 探讨免疫组织化学在皮肤毛母细胞瘤（trichoblastoma，TB）与基底细胞癌（basal cell carcinoma，BCC）鉴别诊断中的应用价值。 方法： 回顾性分析2009年1月至2019年12月复旦大学附属肿瘤医院收集的58例TB与40例BCC，观察记录bcl-2、Ber-EP4、CD10、CK20和Ki-67免疫组织化学染色表达与差异，并行统计学分析。 结果： 25例（43.1%）TB bcl-2阳性表达定位于基底样上皮巢团周边细胞，BCC中仅有5例（12.5%），两组病例bcl-2阳性表达方式差异具有统计学意义（P<0.01）。bcl-2阳性细胞数比例>75%的病例数在BCC组中所占比例高于TB组（40.0%和12.1%，P<0.01）。BCC组中Ber-EP4阳性细胞数比例>75%与51%~75%的病例数所占比例均多于TB组（分别为12.5%和1.7%，37.5%和8.6%），两组间差异均有统计学意义（P<0.05）。在TB组中55例（94.8%）毛源性间质CD10阳性，而BCC组中仅16例（40.0%）存在少量或局部反应性纤维化间质CD10阳性（P<0.01）。TB组中37例（63.8%）有散在或星空状的CK20阳性表达，而BCC组中仅1例（2.5%）局部区域存在少量散在细胞阳性（P<0.01）。BCC组中Ki-67阳性指数平均值≥15%与Ki-67热点区域阳性指数≥25%的病例数所占比例均显著高于TB组（P<0.05）。 结论： 免疫组织化学染色标记在TB与BCC的鉴别诊断中具有一定应用价值。基底样上皮CK20散在阳性和上皮巢团周边间质细胞成分表达CD10支持TB。bcl-2阳性定位于瘤巢周边的表达方式更常见于TB中。而BCC中Ber-EP4和Ki-67的阳性比例和阳性指数相对更高。.