Uterine inner myometrial echogenic foci. Relationship to prior dilatation and curettage and endocervical biopsy.

The frequent presence of small echogenic foci within the inner myometrium in women who have had prior uterine instrumentation is reported. Bright foci were observed in 35 of 80 patients who had had prior dilatation and curettage or endocervical biopsy and in only 2 of 174 patients who gave no history of either procedure (P less than 0.005). These foci tend to be small (3 to 6 mm), linear, usually nonshadowing, single or multiple, and located immediately adjacent to the endometrium anywhere along the length of the endometrial cavity; they can be seen many years after the procedure was performed. The histopathologic features of these foci are unconfirmed, but we suspect they represent calcification or fibrosis at sites of mechanical injury to myometrium. The presence of these foci serves as a marker of prior instrumentation and probably has no clinical significance. However, sonographers who are aware of their possible occurrence, can avoid mistaking them for leiomyoma calcifications or for air in the endometrium or myometrium in patients with suspected endometritis.