LAUSR

To the Editor, The recent online publication of the article entitled “A histopathologic approach to uterine niche: What to expect and to report in hysteroscopy-resected isthmocele specimens” in the “International Journal of Surgical Pathology”, has shown some absent or scarce histopathologic features in hysteroscopy-resected isthmocele specimens compared to previously reported cases of isthmoceles in hysterectomy specimens.1–5 We became interested in the histopathologic features in isthmoceles that can be identified in hysterectomy specimens which might have been absent or obscured in hysteroscopy-resected isthmoceles. Our aim this time is to compare and contrast the clinicopathologic features of isthmoceles procured from hysterectomy and isthmoplasty specimens. We retrieved hysterectomy specimens from our pathology archive file that included isthmoceles by performing a retrospective review over a 10-year period. We have collected relevant clinical data for each patient such as age, clinical presentation, number of Caesarean sections, and reason for hysterectomy. We retrieved the hematoxylin and eosin slides of the sampled isthmoceles from each hysterectomy case. We looked for the types of the lining mucosa, luminal contents and the edge wall stroma, as well as the underlying residual myometrial tissue, the scar area, and fibrofatty tissue separating the base of the pouch from the resected uterine margin. We looked for the presence and pattern of hemorrhage, cysts, fibroblastic stroma, metaplasia, epithelial atypia, inflammation and foreign body giant cell reaction. We searched for histopathologic findings which were present in hysterectomy-isthmoceles, but either were not identified or masked in our previous cases of hysteroscopy-isthmoceles. We also recorded accompanying uterine lesions. We found 32 cases of isthmoceles procured from hysterectomy specimens. On average, the patients in our current hysterectomy group were older than our previous hysteroscopy group (Table 1). The patients complained of menorrhagia, dysmenorrhea and postmenopausal bleeding because they had adenomyosis, leiomyomas, endometrial polyps and endometriosis which were more prevalent in the hysterectomy group. In contrast to hysteroscopy group, brownish mucoid vaginal discharge and intermenstrual (postmenstrual) spotting and bleeding were not reported. The patients had on average similar number of previous Caesarean sections, but of a longer duration since the last Caesarean section. These patients had the choice of hysterectomy for symptomatic relief because they have completed their families. Three patients did not have radiologic investigations, nine cases of the isthmoceles were identified during radiologic investigations, and the remaining isthmoceles were identified during gross pathologic examination of the hysterectomy specimens. Histologically, similar to our previous series of isthmoplasty specimens, the hysterectomy-isthmoceles showed endocervical, endometrial and isthmic lining mucosa either isolated or combined. However, endometrial lining and isthmoendometrial lining were more prominent in hysterectomy-isthmoceles (Table 1). In contrast to hysteroscopy-isthmoceles, the hysterectomy-isthmoceles showed luminal hemorrhage with cellular degenerate debris material and subepithelial hemorrhagic mucosal stroma and congested capillaries (Figure 1A to C). The mucosal lining showed foci of spontaneous surface sloughing and discontinuity particularly at the base (Figure 1A and C). Similar to hysteroscopy-isthmoceles, endocervical cysts were present, but endometrial and isthmic cysts were also present, were intact, larger, multiple, clustered and