From Big Medical Encyclopedia

ARIAS-STELLA PHENOMENON (reaction) — the atipichesky changes of cells of an endometria arising at pregnancy, a vesical drift and a horionepitelioma and which are characterized by existence of hypertrophied kernels with fragmentation. Are described Arias-Stella (J. Arias-Stella) in 1954. At A.-S. f. swelling of cells, vacuolation of protoplasm, polymorphism, a hyperchromasia, a hypertrophy of kernels with fragmentation is observed. The changed single cells or groups them meet in single or in many glands of an endometria. Mitoses and multinucleosis in epithelial and connective tissue cells of an endometria are quite often noted. Arias-Stella observed similar changes at the broken pregnancy (uterine or extrauterine), at a vesical drift, a horionepitelioma. Some authors connected A.-S.'s emergence f. with inflammatory, regressive changes at abortion. However it was established later that A.-S. f. appears almost constantly and at normally proceeding pregnancy. According to Arias-Stella, atipichesky changes in kernels of epithelial cells of an endometria are caused by the combined hormonal influence of a chorial gonadotrophin and sex hormones. This situation is confirmed by the author in an experiment. Introduction to nonpregnant rats of a chorial gonadotrophin and oestradiol-propionate caused the atipichesky changes in cells of an endometria similar observed at A.-S. f. At the castrated animals similar changes were not observed.

Detection of changes in an endometria in some cases allows to establish existence of the broken pregnancy of small terms broken extrauterine pregnancy (see). Atipicheski the changed cells of an endometria at A.-S. f. can be mistakenly taken for malignant. Therefore at suspicion of a malignant tumor at women of childbearing age it is necessary to remember A.-S. f. and to conduct especially careful examination and observation carefully to otdifferentsirovat A.-S. f. from a malignant tumor.

Bibliography: Arias - Stella J. Atypical endometrial changes associated with presence of chorionic tissue, Arch. Path., v. 58, p. 112, 1954; Vago O., Paseu F. u. Roman L. Zur Bewertung des Arias-Stellaschen Phänomen in der Diagnose der Extrauterin-Schwangerschaft, Zbl. Gynäk., Bd 88, S. 497, 196,6.

C. H. Kopshev.