The Natural History of Uterine Leiomyomas: Light and Electron Microscopic Studies of Fibroid Phases, Interstitial Ischemia, Inanosis, and Reclamation
Figure 18
Ultrastructure of inanosis and reclamation. Electron microscopic examination of fibrotic areas in fibroids provides even more dramatic evidence of shrunken myocytes, widely spaced within the fibrotic stroma. In (a), there is a cluster of cells which have retained some cytoplasm (arrow) and provide a frame of reference for the small, shrunken cells. In (b), a cell in the lower right (long arrow) exhibits cytoplasmic budding, with one or two of these knob-like fragments apparently pinching off from the cell membrane (small arrow); we refer to this as decapitation membrane budding. Note that the loose, watery stroma contains numerous particles of cellular debris (arrowheads), without any evidence of inflammatory cell infiltrate or phagocytosis. In (c), the shrunken cell in the lower right (short arrow) contrasts with the less atrophic cell in the upper left (long arrow). The cytoplasm of the shrunken cell contains vacuoles, lysosomes, and degenerating organelles with few remaining myofilaments. The slender, atrophic cell in the center of the fibrotic field in (d) has retained its shape and endoplasmic reticulum (arrow), but has lost most of its myofilaments. The surrounding matrix contains abundant cellular debris (arrowheads), imparting a junkyard appearance. In (e), there is an autophagosome (long arrow) containing ribosomes (short arrows) and membranous debris which could be of endoplasmic reticulum origin (arrowhead). The remainder of the contents of the autophagosome resembles the adjacent cytosol and probably consists of degenerated myofilaments. The nucleus (asterisk) is in the upper right of the image. The cell in (f) exhibits two double membraned autophagosomes (arrows) containing electron-dense membranous debris. Original magnification of (a): 1700x, (b): 1250x, (c): 2550x, (d): 2550x, (e): 43,000x, and (f): 20,500x.
