WWOX inmunohistochemical staining in ovarian carcinoma samples by histotypes. A-C. Serous ovarian carcinomas. A, Strong-Moderate. Note heterogeneity in staining intensity pattern in this tumor sample; B, Moderate. Note predominance of apical staining in this papillary serous ovarian carcinoma; C Weak-Negative, WWOX lack of staining observed in approximately 30% of serous carcinoma cases. D-F. Endometroid ovarian carcinomas. D and E positive WWOX cytoplasmic staining and F negative staining. G-I. Clear Cell ovarian Carcinomas. G, representative photomicrograph of one of a moderately WWOX positive CCC case, while H and I, represent typical negative cases. J-L. Mucinous ovarian carcinomas, J, representative mildly positive case and K representative mucinous carcinoma of the endocervicoid subtype with demonstrating no WWOX staining. L, mucinous carcinoma of the intestinal subtype also negative for WWOX staining.