Abstract Background: The hair follicle is a unique structure, one of the most dynamic structures in mammalians, which can reproduce in every new cycle all the mechanism involved in its fetal development. Although a lot of research has been made about the human hair follicle much less has been discovered about the importance of the cytokeratins (CKs) in its development. Objective: Study the immunohistochemical pattern of epithelial CKs during human hair follicle development. Methods: We performed an immunohistochemical study using fresh post-mortem skin biopsies of human fetuses between 4 and 25 weeks of gestational age to study the expression of cytokeratins (CKs): CK1, CK10, CK13, CK14, CK16 and CK20 during human hair follicle fetal development. Study limitations: Restrospective study with a good number of makers but with a small population. Results/conclusion: We found that, the CKs were expressed in an intermediate time during follicular development. The epithelial CKs (CK1, CK14, CK10, CK13) and the epithelial CKs with a proliferative character such as CK16 were expressed first, as markers of cellular maturation and follicular keratinization. At a later phase, CK20 was expressed in more developed primitive hair follicles as previously discussed in literature.

Abstract Papillary intralymphatic angioendothelioma (Dabska tumor) is a rarely metastasizing lymphatic vascular neoplasm that usually affects children and young adults. The majority of these cases occur in soft tissues of extremities, and to date less than 40 cases have been described. Despite the generally indolent evolution, can be locally invasive with the potential to metastasize. We describe a case of a young woman presenting with a plantar lesion, for 9 months and histological diagnosis of Dabska tumor. This neoplasm should be considered in the differential diagnosis of vascular dermatoses, allowing early diagnosis and treatment. Long-term follow-up should be performed.