Decidual transformation in adenomyosis during pregnancy as an indication for hysterectomy

INTRODUCTION: Incidence of adenomyosis is estimated on 20% in all of extracted uteruses. Clinically, it usually exists asymptomatically, but could be followed with dysmenorrhoea, menorrhagia and pelvic pain. One third of patients with adenomyosis are sterile, however in other two thirds, conception and pregnancy could have normal development, with delivery without complications. One of possible complications related to adenomyosis is rupture of uterus during delivery. CASE REPORT: A pregnant woman at the end of the 10th lunar month of pregnancy, showed minimal labour contractions, following amnion rupture and the delivery was terminated by section ceasar. Subtotal hysterectomy was performed because of concominant profuse bleeding. Myometrium was occupied with decidual cells in trabecular arrangement, among which elongated endometrial glands were placed. Surrounding muscle fascicles showed atrophic, apoptic, and occasionally necrotic changes. Myometrial stroma was edematous, and infiltrated with mesenchymal cells, as well as with adipose cells, which were extending toward serosa. DISCUSSION: The patient had been receiving treatment, for a long period, because of sterility without clear etiological factor. A small number of similar cases ends with complications. Here, it is evident that abundant decidual transformation of stromal cells in adenomiosis leads to atrophy and necrosis of muscle cells. The reduction of uterine muscle mass causes atony and threating rupture, through separation of muscle cells, and therefore the absence of their synchronized contractions. CONCLUSION: Atony of uterine muscle could be caused by decidual transformation in adenomyosal fields, atrophy of muscle fascicles, edema of the stroma, mesenchymal transformation, and fibrosis. This leads to a decrease in myometrial contractions, and prolonged postpartal bleeding.