Surveys/detail of the decidua basalis and intervillous space of the placenta (human placenta, late midpregnancy)

Stain: Hematoxylin ?azophloxine (A, C), Trichrome (Goldner) (B). Left pictures (A, B): The maternal side at the bottom consists of a broad zone of the stripped basal decidua (1) intermingled with reddish matrix-type fibrinoid accumulations and streaks (Rohr) (2), close to the anchoring villi (3) and the trophoblastic shell (4), while deeper in the deciduous myometrium the Nitabuch?s matrix-type fibrinoid layer is normally localised (not present in this picture due to the stripping). Thick light-stained stem villi (5) with distinct blood vessels ramify into terminal villi (arrows 6). Arrows point to multinucleated trophoblast giant cells close to the anchoring villi and fibrinoid striae; these giant cells are derived from the fusion of former mononuclear cytotrophoblast cells (CTCs) forming the trophoblastic shell (see also scheme in POJA-L1227). (7) also points to trophoblast cells as part of the trophoblastic shell. At (8) commonly found hyaline degenerated remnants of former villus and at (9) epitheloid decidua cells are faintly visible (middle picture). Right picture (C) reveals the characteristic aspect of deciduous transformed endometrial stromal cells. Note the larger, polygonal and fine filamentous cytoplasms. Locally darker-stained lymphocytes (10 in C) are often interspersed. The decidua cells (9) contain glycogen, lipids and vimentin intermediate filaments (stromal cells from mesenchymal origin) and produce various secretion products such as insulin-like growth factor, prolactin etc. and are involved in the remodelling of the stromal extracellular matrix in order to modulate the degradative activity of the trophoblast cells. (2) points to reddish-stained matrix-type fibrinoid deposit.