Prenatal Development of Sebaceous Gland: Morphologic and Morphometric Observation

ABSTRACT

This study was conducted to illustrate the histological and morphometric features of the sebaceous gland of human fetal skin. For this purpose, we studied 12 human embryos and 60 fetuses from the 4 th to 38 th week of gestation. In each case, we sampled eight different areas of skin, i.e., scalp, forehead, face, chest, abdomen, back, extremity, and palm and sole. Through routine tissue processing, hematoxylin and eosin preparations were made for morphology and morphometric analysis. The sebaceous gland anlagen is noted in the face and scalp by the 14th week of gestation, being subsequently generalized in other parts of the body, namely by 16th week of gestation. The lobation of the sebaceous gland subsequently differentiated into multilobular appearance in the face and scalp by the 17th week of gestation and in the chest and abdomen by the 26th week of gestation. The sebaceous ducts were seen by the 21th week of gestation in face and scalp, and in the chest and abdomen by the 27th week of gestation. In morphometric observation, the number and diameter of sebaceous gland were reached its peak during the 21st to 24th week of gestation, and then decreased gradually until it became constant in later days of the gestational period. In general, cephalic portion of the body had more sebaceous glands and also was larger in diameter. This difference became negligible as fetuses reached the term.