Milky Spots

MILKY SPOTS (macula lactea, French taches laiteuses), local changes in serous membranes expressed in the formation of single or multiple milk-white spots of various sizes on them. Milky spots represent a purely morphological concept, uniting formations that are essentially completely different. 1) On serous membranes, especially often on the surfaces of the greater omentum, small whitish spots are found as normal formations, which Ranvier called taches laiteuses; these milky spots consist of accumulations of cells of the clasmatocyte (macrophage) type and, in their physiological significance, are associated with the processes of absorption and intracellular digestion occurring in the serous membranes, especially the omentum. 2) On the visceral layer of the pericardium, flat thickenings of the serous membrane having the appearance of white spots with sharp contours are very often observed (in 80% of all corpses); under the microscope, they turn out to consist of proliferating connective tissue, sometimes including glandular-like passages lined with cuboidal epithelium (the result of the separation of serous epithelium). These formations on the pericardium are also called milky spots or tendon spots (macula lactea, s. tendinea). According to their origin, they are of three kinds: a) Those of them that are distributed unevenly over the epicardium, occupying not infrequently the surface of the atria as well as the posterior surface of the heart, and at the same time having an uneven surface, represent the result of past pericarditis, usually of a rheumatic character; b) Spots that are smooth and shiny on the surface, localized in certain places of the heart, specifically most often on the anterior surface of the right ventricle in the region of the conus arteriosus pulmonalis and along the course of the coronary arteries, are the consequence of mechanical causes: friction and constant impacts during systole and diastole of the heart. These milky spots of the cardiac callus type are encountered predominantly in elderly individuals; c) Milky spots observed sometimes in early childhood in the region of the anterior surface of the apex of the heart in the form of a translucent thickening of the epicardium, which in cross-section often appears to consist of mucous tissue, belong to developmental defects, specifically to the consequences of adhesion of the anterior surface of the heart with the amnion during the period of the open ventral cavity (German Amnionflecken).