Sardiña Luis A, Rubin Brian, Jour George, Piliang Melissa, Elston Carly, Bergfeld Wilma F
Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio.
Departments of Pathology and Dermatology, New York Langone Medical Center, New York, New York.
J Cutan Pathol. 2019 Apr;46(4):256-260. doi: 10.1111/cup.13411. Epub 2019 Feb 10.
The role of the mammalian target of rapamycin (mTOR) in hair follicle tumorigenesis is unclear. mTOR controls cell growth and can be activated through ribosomal S6 kinase. Herein, we sought to evaluate the expression of phospho-S6 in six different benign and malignant follicular tumor types.
76 cases were selected (17 fibrofolliculomas, 20 trichoepitheliomas, 10 tricholemmomas, 19 pilomatricomas, 1 malignant proliferating tricholemmal tumor, 8 tricholemmal carcinomas, and 1 trichoblastic carcinoma) and collected over 16 years. Immunohistochemistry with monoclonal antibody for phospho-S6 was performed and analyzed semi-quantitatively; statistical analysis using the χ test was performed, with P < 0.05 considered significant.
All malignant neoplasms in our series (8/8 [100%] cases of tricholemmal carcinoma, 1/1 [100%] trichoblastic carcinoma, and 1/1 [100%] malignant proliferating tricholemmal tumor) showed a strong and diffuse pattern of staining for phospho-S6 involving 70% to 90% of tumor cells. By contrast, a minority of benign tumors were positive for phospho-S6 and most stained in a patchy pattern including 12/17 (71%) fibrofolliculomas, 9/20 (45%) trichoepitheliomas and 1/10 (10%) tricholemmomas, involving 30% to 50%, 5% to 20%, and 40% to 50% of tumor cells, respectively. Most pilomatricomas (17/19 [89%]) exhibited a stronger, but distinctive staining pattern, staining mostly the basaloid cells with a multifocal distribution, involving 70% to 90% of tumor cells.
Phospho-S6 is differentially expressed among benign and malignant hair follicle tumors (P = 0.0044). While malignant tumors show diffuse expression, only a small subset of benign neoplasms were positive, primarily in a patchy distribution.
雷帕霉素哺乳动物靶点（mTOR）在毛囊肿瘤发生中的作用尚不清楚。mTOR控制细胞生长，并可通过核糖体S6激酶被激活。在此，我们试图评估磷酸化S6在六种不同的良性和恶性毛囊肿瘤类型中的表达情况。
选取76例病例（17例纤维毛囊瘤、20例毛发上皮瘤、10例毛鞘瘤、19例毛母质瘤、1例恶性增殖性毛鞘瘤、8例毛鞘癌和1例毛母细胞癌），收集时间超过16年。采用抗磷酸化S6单克隆抗体进行免疫组织化学检测并进行半定量分析；采用χ检验进行统计学分析，P<0.05为差异有统计学意义。
我们系列中的所有恶性肿瘤（8/8 [100%]例毛鞘癌、1/1 [100%]例毛母细胞癌和1/1 [100%]例恶性增殖性毛鞘瘤）均显示磷酸化S6呈强而弥漫性染色模式，累及70%至90%的肿瘤细胞。相比之下，少数良性肿瘤磷酸化S6呈阳性，大多数呈斑片状染色，包括12/17（71%）例纤维毛囊瘤、9/20（45%）例毛发上皮瘤和1/10（10%）例毛鞘瘤，分别累及30%至50%、5%至20%和40%至50%的肿瘤细胞。大多数毛母质瘤（17/19 [89%]）表现出更强但独特的染色模式，主要对基底样细胞进行多灶性染色，累及70%至90%的肿瘤细胞。
磷酸化S6在良性和恶性毛囊肿瘤中的表达存在差异（P = 0.0044）。恶性肿瘤呈弥漫性表达，而只有一小部分良性肿瘤呈阳性，主要呈斑片状分布。
