Plumb Stephen J, Argenyi Zsolt B, Stone Mary S, De Young Barry R
Departments of Pathology and Dermatology, University of Washington, Seattle, Washington, USA.
Am J Dermatopathol. 2004 Dec;26(6):447-51. doi: 10.1097/00000372-200412000-00001.
The differentiation of primary cutaneous adnexal neoplasms (CANs) from dermal-based metastatic lesions can be difficult. Cytokeratin 5/6 (CK 5/6) has a relatively limited expression profile, being relatively specific for mesothelium and other "pavement" type epithelium such as squamous epithelium. To date, the degree and distribution of CK 5/6 expression in cutaneous neoplasms has not been extensively studied. We speculate that since most of CANs arise from similar epithelium, they should express CK 5/6 and, therefore, CK 5/6 could potentially be helpful in distinguishing these lesions from most of metastatic neoplasms, which usually do not express this marker. Formalin-fixed, paraffin-embedded tissue sections from 228 previously classified CANs and 27 metastatic adenocarcinomas (17 breast, 4 colon, 2 prostate, 2 ovary, 1 lung, and 1 esophagus) were immunostained with anti-CK 5/6. Anti-CK 5/6 labeled 2 of 2 proliferating trichilemmal tumors, 6 of 6 poromas, 4 of 5 hydrocystomas, 10 of 10 cylindromas, 10 of 10 eccrine acrospiromas, 8 of 10 pilomatricoma, 10 of 10 nevus sebaceus, 9 of 9 desmoplastic trichoepitheliomas, 7 of 7 nevus sebaceus with basal cell carcinomas, 10 of 10 pilar cysts, 14 of 14 trichilemmomas, 10 of 10 syringomas, 6 of 7 chondroid syringomas, 10 of 10 hidradenoma papilliferum, 9 of 9 sebaceus adenomas, 3 of 3 microcystic adnexal carcinomas, 10 of 10 eccrine spiradenomas, 4 of 4 syringocystadenoma papilliferum, 3 of 5 ocular sebaceous carcinomas, 28 of 28 basal cell carcinomas, 16 of 16 trichoepitheliomas, and 33 of 33 trichoepitheliomas with basal cell features. By contrast, 9 of 27 metastatic adenocarcinomas stained positively, although only two of these stained strongly. Cumulatively, CK 5/6 was expressed by most (97%) of CANs, while only 33% of metastatic adenocarcinomas showed positive expression. The sensitivity of this marker in the malignant lesions (other than basal cell carcinoma) is 78%, while the specificity is 67%. If all lesions are considered, the sensitivity increases to 97%. Therefore, CK 5/6 may prove to be a useful adjunct marker in distinguishing CANs from metastatic lesions.
原发性皮肤附属器肿瘤（CANs）与真皮源性转移瘤的鉴别可能具有挑战性。细胞角蛋白5/6（CK 5/6）的表达谱相对有限，对间皮和其他“铺路石”样上皮（如鳞状上皮）具有相对特异性。迄今为止，CK 5/6在皮肤肿瘤中的表达程度和分布尚未得到广泛研究。我们推测，由于大多数CANs起源于相似的上皮，它们应该表达CK 5/6，因此，CK 5/6可能有助于将这些病变与大多数通常不表达该标志物的转移瘤区分开来。对228例先前分类的CANs和27例转移性腺癌（17例乳腺癌、4例结肠癌、2例前列腺癌、2例卵巢癌、1例肺癌和1例食管癌）的福尔马林固定、石蜡包埋组织切片进行抗CK 5/6免疫染色。抗CK 5/6标记了2例增殖性外毛根鞘瘤中的2例、6例汗孔瘤中的6例、5例汗腺囊瘤中的4例、10例圆柱瘤中的10例、10例小汗腺末端汗腺瘤中的10例、10例毛母质瘤中的8例、10例皮脂腺痣中的10例、9例促结缔组织增生性毛上皮瘤中的9例、7例合并基底细胞癌的皮脂腺痣中的7例、10例毛囊肿中的10例、14例外毛根鞘瘤中的14例、1例汗管瘤中的10例、7例软骨样汗管瘤中的6例、10例乳头汗腺瘤中的10例、9例皮脂腺腺瘤中的9例、3例微囊性附属器癌中的3例、10例小汗腺螺旋腺瘤中的10例、4例乳头状汗管囊腺瘤中的4例、5例眼皮脂腺癌中的3例、28例基底细胞癌中的28例、16例毛上皮瘤中的16例以及33例具有基底细胞特征的毛上皮瘤中的33例。相比之下，27例转移性腺癌中有9例呈阳性染色，尽管其中只有2例染色强烈。总的来说，大多数（97%）的CANs表达CK 5/6，而只有33%的转移性腺癌呈阳性表达。该标志物在恶性病变（基底细胞癌除外）中的敏感性为78%，特异性为67%。如果考虑所有病变，敏感性会增加到97%。因此，CK 5/6可能被证明是区分CANs与转移瘤的一种有用的辅助标志物。
