G1. a, b Irregular protrusion patterns recognize some irregular small projections at the edges of cell clumps. The margin of the cytoplasm of those small projections is clearly observed. c As for the papillotubular patterns, endometrial gland shows a papillary growth pattern with irregular branching and projections. Cohesion of the endometrial stromal cells is not noted at the margins of the gland. d When the papillary structure is complex and confluent, much glandular space is formed and back-to-back structures with a cribriform pattern are also recognized. SurePath LBP, Papanicolaou stain. Original magnifications: ×20 (a, c, d); ×40 (b).