Department of Dermatology, Nara Medical University School of Medicine, Kashihara, Japan.
Department of Pathology, Fukuoka University School of medicine, Fukuoka, Japan.
J Cutan Pathol. 2022 Jun;49(6):515-524. doi: 10.1111/cup.14214. Epub 2022 Feb 22.
Cysts of the skin are observed frequently and their diagnoses are generally straightforward. However, atypical cystic lesions for which differentiation is indistinct have been noted.
We examined five cases of trichilemmal cyst with proteinaceous material (TCPM), which required differentiation from sweat duct/gland tumors. We investigated the histopathological findings of TCPMs and evaluated the immunohistochemical expression of cytokeratin (CK) 10, CK13, CK17, CK19, CD8, and CD117. Immunohistochemical analysis was performed on the 5 TCPMs, 10 trichilemmal cysts (TCs), 5 clear-cell hidradenomas, 5 poroid hidradenomas, and cutaneous normal adnexa.
Apoptotic cells were present in the cyst wall with a small amount of keratin or calcification in the cavity of TCPMs. The TCPMs and TCs were negative for CK19 and CD117, on the other hand clear-cell hidradenoma and poroid hidradenoma were positive for CK19 and CD117. The restricted positivity for CK10 was detected in the suprabasal layers of the cyst walls of TCPMs and TCs. The immunostaining patterns of TCPMs and TCs were similar to those of normal follicular isthmus.
The histopathological findings with characteristics of TCs and a panel of immunohistochemical antibodies including CD117, CK19, and CK10 contributed to a correct diagnosis of TCPM.
皮肤囊肿较为常见，其诊断通常较为直接。然而，也存在一些鉴别困难的非典型囊性病变。
我们研究了 5 例伴有蛋白样物质的毛鞘囊肿（TCPM），这些病例需要与汗腺/腺肿瘤相鉴别。我们分析了 TCPM 的组织病理学特征，并评估了细胞角蛋白（CK）10、CK13、CK17、CK19、CD8 和 CD117 的免疫组化表达。对 5 例 TCPM、10 例毛鞘囊肿（TCs）、5 例透明细胞汗腺瘤、5 例小汗腺汗腺瘤和皮肤正常附件进行了免疫组化分析。
TCPM 的囊壁可见凋亡细胞，腔内有少量角蛋白或钙化。TCPM 和 TCs 对 CK19 和 CD117 均为阴性，而透明细胞汗腺瘤和小汗腺汗腺瘤则对 CK19 和 CD117 均为阳性。TCPM 和 TCs 的囊壁的基底层有 CK10 的局灶性阳性。TCPM 和 TCs 的免疫组化模式与正常滤泡峡部相似。
TCs 的组织病理学特征和包括 CD117、CK19 和 CK10 在内的一组免疫组化抗体有助于正确诊断 TCPM。
