Histologic classification and pathologic findings for endometrial biopsy specimens obtained from 2964 perimenopausal and postmenopausal women undergoing screening for continuous hormones as replacement therapy (CHART 2 Study).

OBJECTIVE: The aim of this study was to screen for disorders and to histologically classify endometrial biopsy specimens from 2964 perimenopausal and postmenopausal women who were candidates for hormonal replacement therapy. STUDY DESIGN: Endometrial biopsy specimens were obtained with a Vabra aspiration curette, processed by standard methods, and stained by hematoxylin and eosin and special methods to reveal subtle features of the endometrium. RESULTS: Of the endometrial biopsy specimens, 68.7% were atrophic, 23.5% were proliferative, 0.5% were secretory, 0.6% were hyperplastic, 0.07% were adenocarcinoma, and 6.6% were insufficient for classification. Three independent senior microscopists agreed on the classification of each biopsy specimen. CONCLUSION: The number of patients is the largest ever screened for a single hormone replacement therapy study. The low yield of endometrial cancer indicates that biopsies are unnecessary before hormone replacement therapy is initiated in asymptomatic women.

Acquisition and retention of viruses by Trichomonas vaginalis.

Recently described occurrence of virus-like particles (VLP) in some strains of Trichomonas vaginalis suggests the possibility that the pathogenic significance of this organism may be broadened by its potential for viral transmission. Inasmuch as neither the source nor the host range of the VLP are known, any hazard which they may present for man cannot be estimated. A model has been established for the study of acquisition of known human viruses by T vaginalis. Tissue cultures were infected with two reoviruses and a fresh isolate of genital herpes simplex virus (HSV). A squirrel monkey reovirus was also included in the study. T vaginalis was inoculated into the virus cultures three days later. The progress of virus acquisition by the trichomonads was monitored by transmission electron microscopy and by culture. Virus-containing cell fragments were engulfed by trichomonads and internalised in vacuoles. After digestion of cellular debris only virus particle aggregates were retained. Viable reoviruses were recovered from the trichomonads for nine days, and HSV for six days. The results suggest the possibility of transmission of at least some viruses by T vaginalis.

Papovavirus in epitheliomas appearing on lymphoma-bearing hamsters: lack of association with horizontally transmitted lymphomas of Syrian hamsters.

Several epizootics of lymphoma occurred in a colony of LVG hamsters contaminated with an unusual, horizontally transmitted, subviral, lymphomagenic agent. Hamsters with horizontally transmitted lymphoma, or others housed with these hamsters, occasionally developed epitheliomas bearing an unclassified papovavirus. The possibility that the virus present in the wart-like structures in our hamster colony could activate lymphoma was tested, and a search was conducted for mature virions in passaged epitheliomas and lymphomas. The agent responsible for the skin epitheliomas in our hamster facility was an icosahedral, 36-nm virion compatible with the morphology of a polyomavirus or simian virus 40. Horizontally transmitted lymphoma cells and epitheliomas contained hamster papovavirus (HaPV) DNA sequences detected by dot hybridization; however, such sequences were not found in extracts of lymphomas with oncogenic potential. In contrast to reports by other investigators, infection of hamsters with the papovavirus present in primary epitheliomas produced epitheliomas in good yield but was not reproducibly associated with lymphoma induction. These data confirm the observation that the HaPV is the causative agent of epitheliomas, but they suggest clearly that HaPV is not the agent responsible for lymphomagenesis.

Mechanisms of uterine bleeding in postmenopausal patients receiving estrogen alone or with a progestin.

The response of postmenopausal endometrium to cyclic estrogen and progestin and cyclic estrogen alone was studied in 75 biopsies and over 2000 preparations using standard histologic, histochemical, and scanning and transmission electron microscopic techniques. Estrogen and a progestin caused the atrophic endometrium to assume normal proliferative and secretory phases and to develop nucleolar channel systems. Cyclic unopposed estrogen produced unphysiologic responses in the glands, stromal cells, and vessels. The concept of a progestin or progesterone producing a "medical curettage" should be reappraised. Cyclic estrogen and progestin therapy do not cause all the endometrium to desquamate to the basalis layer. The combination therapy is associated with increased glycoprotein production in the gland and stromal cells, and an orderly regression and remodeling of the endometrium upon hormonal withdrawal. Cyclic estrogen alone causes irregular and unpredictable breakdown, which may or may not extend to the basalis. The stimulation of the endometrium by estrogen alone may allow the endometrium to use the majority of its energy for growth, which may lead to hyperplasia and neoplasia.

Ultrastructure of endometrium of postmenopausal patients on two modes of hormonal therapy: estrone sulfate with or without MPA.

The response of human postmenopausal endometrium to standard, oral doses of an estrogen alone (estrone sulfate) and to an estrogen plus a progestin (medroxyprogesterone acetate; MPA) was evaluated by scanning electron microscopy and transmission electron microscopy. Endometrial biopsies were obtained over a 4-year period from 12 patients with well-established ovarian failure. Biopsies were taken before the initiation of therapy and during each mode of hormonal treatment. The ability of estrone sulfate alone to stimulate growth of the endometrium was shown during the 1st treatment cycle when the atrophic epithelial cells transformed into tall columnar cells which synthesized and released some secretory products. Unopposed estrogen therapy led to excessive ciliation and breakthrough bleeding. Addition of MPA to the estrone sulfate regimen produced a progestational endometrium. The epithelial cells had ultrastructural features of those in normal postovulatory endometrium, including nucleolar channel systems. MPA elicited deciliation and transformation of ciliated cells into secretory cells. Stromal cells hypertrophied, the vascular endothelium thickened, and bleeding subsided. Estrogen-progestin therapy as tremendously more physiological than unopposed estrogen therapy.