The Natural History of Uterine Leiomyomas: Light and Electron Microscopic Studies of Fibroid Phases, Interstitial Ischemia, Inanosis, and Reclamation
Figure 19
Ultrastructure of inanosis and reclamation. The nucleus in (a) is lying free within the stroma and shows a swollen, discontinuous nuclear envelope (arrowhead) that is being resorbed. The nucleus itself appears relatively intact except for the whorl in the lower right (arrow). Note the loosely expanded, watery stroma (asterisk) surrounding the nucleus. The nucleus of the shrunken cell in (b) displays a rippled or serrated border (short arrow) resembling the acanthanuclear alteration sometimes seen with the light microscope. The large vacuolar structure in the cytoplasm (arrowhead) could be dilated endoplasmic reticulum or possibly a phagolysosome and may correspond to the cytoplasmic vacuoles seen with the light microscope. The cytoplasmic tail at the left (long arrow) is degenerated and could be a precursor to autoamputation. In (c), myofilaments (long arrow) appear to lie outside of the cell membrane within a loosely expanded, watery stroma, suggesting that they have either leaked out or have been extruded. Three phagolysosomes (short arrows) are present in the cytoplasm of the cell. The cell in (d) shows budding of cytoplasmic debris (long arrows) from the elongate end of the cell. Some of the rounded particles could be autophagolysosomes with free ribosomes and degenerated cytoplasm. The cytoplasm of the cell consists almost entirely of dilated ER and swollen mitochondria (short arrow), with few remaining filaments. The tail of the cell in (e) exhibits complete degeneration of cytoplasm and organelles (arrows), with apparent loss of the cell membrane, while the remaining portion of the cell on the right (arrowhead) appears to be viable; the appearance suggests that cells might be capable of segmental autoamputation. The cell in (f) illustrates both the end stage of inanosis and the resorptive process of reclamation. The cytoplasmic contents are degenerated, granular, and vacuolated (short arrow), and the cell membrane has been breached in some areas, resulting in extrusion of degenerated cytoplasm into the adjacent watery stroma with disrupted collagenous matrix (arrowhead). The nuclear chromatin is condensed, and there is a degenerative structure in the middle (long arrow). Note that in each photo ((a)–(f)), the inanotic cells or cell particles are surrounded by loosely expanded, watery stroma, which is believed to correspond to the clear spaces sometimes seen around inanotic cells with light microscopy and thought to represent resorption pits associated with the reclamation process. Original magnification of (a): 26,500x, (b): 9,900x, (c): 43,000x, (d): 9,900x, (e): 9,900x, and (f): 9,900x.
