A 57 year old woman presented with postmenopausal uterine bleeding.
A TruTest® endometrial biopsy was performed using a Tao Brush® to sample the endometrium. Ample tissue fragments were received and were separated from the endometrial sample by filtration and submitted for histology. The remaining endometrial cytology material was processed by selective cellular enhancement technique and the slides were stained with Papanicolaou and acid hematoxylin methods.
Low power examination of the brushing cytology slides revealed a highly cellular sample containing groups of atypical endometrial cells arranged in small acinar-like groups (Fig. 1 Papanicolau stain) and cribriform structures (Fig 2. acid hematoxylin). The nuclei in these cell groups are round to ovoid and are generally uniform in appearance with slight irregular thickening of the nuclear membrane. The nucleoli are small and there are occasional mitotic figures (Fig. 2). The histologic preparation (Fig. 3, 4, H&E stain) showed complex glandular structures with cribiform and “back to back” glandular patterns. Low grade nuclear features similar to those observed in the cytologic slides were evident (Fig 4).
While these two entities can have similar cytologic nuclear features, the glands in complex hyperplasia are still separated by small amounts of stroma and lack the cribriform and solid epithelial structures seen in low grade endometrioid adenocarcinomas.
Endometrioid Adenocarcinoma, Grade 1
A subsequent hysterectomy revealed and a Grade 1 Endometrioid Adenocarcinoma with myometrial invasion.