Figure 2: Histological and immunohistochemical studies confirming paralumbar muscle endometriosis. (A) Hematoxylin and eosin stain. Endometrial glands and stroma are seen interspersed in muscle, x4. (B) Paired box 8 immunostain. Ectopic endometrial gland nuclei stain positive for PAX8, x20. (C) Cytokeratin immunostain. Endometrial glands stain positive for CK while stromal cells stain negative, x20. (D) Cluster designation 10 immunostain. Ectopic endometrial stroma stain negative for CD10 while endometrial glands stain negative, x20