Honarpisheh Hedieh, Glusac Earl J, Ko Christine J
Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.
J Cutan Pathol. 2014 Dec;41(12):916-21. doi: 10.1111/cup.12410.
Tumors with similar or identical histopathologic features have been termed basaloid follicular hamartoma (BFH) or infundibulocystic basal cell carcinoma (BCC). BCC typically lacks immunoreactivity with cytokeratin 20 (CK20) and pleckstrin homology-like domain, family A, member 1 protein (PHLDA1).
A series of BFH and infundibulocystic BCC were investigated to determine the pattern of CK20 and PHLDA1 labeling in these lesions.
Thirty-six samples of BFH (n = 14) and infundibulocystic BCC (n = 22) were collected. CK20 and PHLDA1 staining was performed and evaluated.
All the lesions were small (average of 3 mm), well circumscribed, and composed of basaloid to squamoid cells arranged in islands resembling ramifying rootlets with interspersed horn cysts. CK20-positive cells were present in all 36 cases (average, 22/mm(2)), throughout the tumor, including deeper portions, irrespective of original diagnosis. Six of thirty cases (20%; 5 infundibulocystic BCC, 1 BFH) were focally PHLDA1 positive.
Findings on hematoxylin and eosin staining and those of CK20 staining in BFH and infundibulocystic BCC were similar, and in most cases were indistinguishable. The CK20 labeling was similar to that of trichoepithelioma. The findings add a degree of support to the argument that BFH and infundibulocystic BCC represent the same lesion and, further, a benign one.
具有相似或相同组织病理学特征的肿瘤被称为基底样毛囊错构瘤（BFH）或漏斗状囊性基底细胞癌（BCC）。BCC通常对细胞角蛋白20（CK20）和 plekstrin 同源样结构域A家族成员1蛋白（PHLDA1）缺乏免疫反应性。
对一系列BFH和漏斗状囊性BCC进行研究，以确定这些病变中CK20和PHLDA1标记的模式。
收集了36例BFH（n = 14）和漏斗状囊性BCC（n = 22）样本。进行并评估了CK20和PHLDA1染色。
所有病变均较小（平均3mm），边界清晰，由基底样至鳞状细胞组成，排列成类似分支小根的岛状结构，并伴有散在的角囊肿。36例病例中均存在CK20阳性细胞（平均22/mm²），遍布肿瘤，包括深部，与最初诊断无关。30例中有6例（20%；5例漏斗状囊性BCC，1例BFH）局部PHLDA1呈阳性。
BFH和漏斗状囊性BCC的苏木精-伊红染色结果及CK20染色结果相似，在大多数情况下难以区分。CK20标记与毛发上皮瘤相似。这些发现为BFH和漏斗状囊性BCC代表同一病变且为良性病变的观点提供了一定程度的支持。
