The Natural History of Uterine Leiomyomas: Light and Electron Microscopic Studies of Fibroid Phases, Interstitial Ischemia, Inanosis, and Reclamation

Figure 2

Fibroid Phases 1–4. Representative examples of the four phases of fibroid development are shown, with the Masson trichrome stain (1x image) on the left and the H&E stain of the same tumor (10x image) on the right. The progressive increase in blue staining collagen from Phase 1 to Phase 4 is well shown in the Masson trichrome stained sections. The corresponding H&E images on the right also demonstrate the virtual absence of collagen in the Phase 1 tumor, the appearance of interspersed pink collagenous fibers (arrow) in Phase 2, the more abundant pale pink collagenous stroma of Phase 3, and the predominance of pink, hyalinized stroma in Phase 4. Note also the abundance of microvessels (small ovoid spaces) in Phase 1 and the paucity of vessels in Phases 3 and 4.