From question on page 1402

Figure 2 shows columnar epithelium (arrow) which is of the non-mucin secreting type, and in fig 3 the surrounding stroma is positive for CD10 (positivity being reflected by the areas of brown staining) consistent with the diagnosis of colonic endometriosis. CD10, a human membrane associated neutral endopeptidase, is widely used in lymphoma phenotyping but it also stains normal, ectopic, …