Al-Zaid Tariq, Ditelberg Jeremy S, Prieto Victor G, Lev Dina, Luthra Raja, Davies Michael A, Diwan A Hafeez, Wang Wei-Lien, Lazar Alexander J
Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030-4009, USA.
J Cutan Pathol. 2012 May;39(5):493-9. doi: 10.1111/j.1600-0560.2012.01888.x. Epub 2012 Apr 5.
Trichilemmoma (TL) can occur as a solitary sporadic lesion usually on the face or as multiple facial lesions almost invariably associated with Cowden syndrome (CS). CS is a multisystem disorder caused by a germline inactivating mutation in PTEN (10q23.31), a tumor suppressor gene. We sought to identify PTEN loss by immunohistochemistry (IHC) in sporadic and CS-associated TL to determine whether IHC is a useful tool to assess an individual for CS.
Six TL biopsies associated with CS and 33 biopsies without CS were retrieved. IHC for PTEN was performed. RESULTS were scored as positive (reactivity in TL cells) or negative (no reactivity in TL cells); normal squamous epithelium and vascular endothelium served as internal positive controls.
Complete PTEN loss was noted in 5/6 (83%) CS-associated TL and 1/33 (3%) sporadic (non-CS) TL.
Demonstration of complete PTEN loss in TL by IHC is strongly suggestive of association with CS, but retention of PTEN staining does not entirely exclude CS. Therefore, PTEN IHC in TLs may be helpful in screening TL for association with CS, but should be used in context with other established clinical criteria, and possibly germline PTEN genotyping to confirm a diagnosis of CS.
毛发上皮瘤（TL）可表现为通常发生于面部的孤立散发性损害，或几乎总是与考登综合征（CS）相关的多发性面部损害。CS是一种由肿瘤抑制基因PTEN（10q23.31）种系失活突变引起的多系统疾病。我们试图通过免疫组织化学（IHC）检测散发性和与CS相关的TL中PTEN的缺失情况，以确定IHC是否是评估个体是否患有CS的有用工具。
收集6例与CS相关的TL活检标本和33例不伴有CS的活检标本。进行PTEN的IHC检测。结果分为阳性（TL细胞中有反应性）或阴性（TL细胞中无反应性）；正常鳞状上皮和血管内皮作为内部阳性对照。
在5/6（83%）与CS相关的TL和1/33（3%）散发性（非CS）TL中观察到PTEN完全缺失。
通过IHC证明TL中PTEN完全缺失强烈提示与CS相关，但PTEN染色阳性并不能完全排除CS。因此，TL中的PTEN IHC可能有助于筛查TL与CS的相关性，但应结合其他既定的临床标准使用，可能还需要进行种系PTEN基因分型以确诊CS。
