CALB2 and neoplasm: The existence of benign Müllerian papilloma, borderline and malignant transformation may be the main diagnostic standard.(figure 1B,F) The exogenous papillary architecture, the expression of CK7, CA125, oestrogen receptor, progesterone receptor and negative for calretinin, vim, CD101 4 5 can be differentiated from mesonephric adenocarcinoma.(figure 2) On biopsy, the solid malignant region may cause misdiagnosis of malignant embryonal rhabdomyosarcoma which was a more common and aggressive tumour in this age group.