The basement membrane in the carcinoma in situ of the cervix: a morphological study

A morphological study of the basement membrane in the carcinoma in situ of the cervix has been carried out. Undifferentiated carcinoma in situ that arises usually from the squamocolumnar junction and which extends into the endocervical canal, always shows a continuous and clearly delineated basement membrane, which runs parallel to the basal layer. It has a homogeneous appearance. The hemidesmosomes attached to the lamina propria are quite normal and there are no slender protrusions from basal cells into the lamina propria. Differentiated carcinoma in situ, that originates in the squamous epithelium of the portio, may extend either in the direction of vagina, or towards the endocervical canal. It is always underlined by a basement membrane loosely constituted of irregular of fragmented reticular fibers; it frequently looses its homogeneous appearance and may be dehiscent or duplicated. Basal cells send down small pseudopods or threadlike extensions into the lamina propria. The authors suggest that in the management of carcinoma in situ of the cervix, one should take into consideration the direction of spread and the stroma-invasion potential of the carcinoma. These histologic patterns carry with them a very important morphologic implication, namely 'cells differentiation' of the carcinoma.