Müllerian and eccrine cutaneous ciliated cysts: Two different entities? the contribution of WT-1 and PAX8 to diagnosis

摘要

To the Editor, Cutaneous ciliated cyst represents a rare benign cystic lesion that mainly affects young women after puberty. It appears as a soft subcutaneous tumor that usually develops within the lower limbs. It is often clinically misdiagnosed as an adnexal cyst or a lipoma, so a definitive diagnosis requires histopathologic study. A 15-year-old woman presented with an asymptomatic subcutaneous nodule on the right hip. This 1-year-old soft lesion was about 1 cm in diameter and had recently grown. No drainage pore was found at the skin surface. She had no relevant medical history, and, no drug had been taken, including oral contraceptives. During the surgical' excision of the lesion, expression of clear fluid was evident. Histopathologic study showed a multiloculated cyst in the deep dermis with a single layer of columnar ciliated and non-ciliated secretory cells (Figs. 1 and 2). Periodic acid-Schiff stain showed the presence of secretory material inside the pseudostratified epithelium. No associated inflammation was present. Immunohistochemistry showed nuclear positivity for estrogen receptor (ER), progesterone receptor (PR) and Wilm's tumor gene-1 (WT-1) (Fig. 3). Expression of epithelial membrane antigen (EMA) and PAX8 was positive in the majority of the cells, including some of the ciliated ones (Fig. 4).