The myothelia (myoepithelial cells). Normal state; regressive changes; hyperplasia; tumors.

TLDR

Myoepithelial cells uniquely combine epithelial and mesenchymal characteristics, connecting to secretory epithelium while interacting with stroma and basal membrane, with dual potentials emerging only under pathological growth. The paper compares myoepithelia across organs, using organ‑specific phenomena to clarify otherwise obscure changes in other tissues. The authors analyze normal myoepithelia, regressive changes, and hyperplasia, then apply these findings to tumor pathology, extending work begun in 1939.

Abstract

The myoepithelial cells are indeed a fascinating type of cell, in that they appear to belong to two widely divergent types of tissues, namely the epithelium and the mesenchyma. This two-sided nature is expressed not only by their position (on the one hand they are connected in typical manner with the secreting epithelium, whereas on the other hand they interact with the stroma and the basal membrane in the same way as smooth muscle fibres), but also by their possession of potentialities of both kinds of tissue, although these potentialities become apparent only under pathological conditions of growth. This concept is the key-note of the following paper, whose purpose is to report a comparative study of the myoepithelia of various organs. Many phenomena that were detectable and detected in only one organ, will be used to elucidate certain otherwise obscure changes in other organs. First we shall examine the normal myoepithelia of various tissues (I), then consider regressive changes (II) and hyperplasia (III), in order to apply the information thus obtained to the problem of tumors (IV, V). To some extent, therefore, this paper constitutes a continuation of my paper from 1939 “On the myothelia of the mammary gland”. Additional material has been collected since then; unfortunately, however, some of the relevant documents were lost during the war and in the post-war period.