TP53 and in situ carcinoma: Cortical inclusion cysts with columnar (Mullerian) epithelia and focal p53 immunoreactivity, but not frank carcinoma, have been reported, but such lesions are relatively rare8,9 Later, attention turned to the fallopian tube epithelium (FTE) as the likely cell-of-origin after serous tubular intra-epithelial carcinomas (STICs), defined as in situ neoplasms with increased proliferative capacity, TP53 mutation, and other characteristic markers, were reported in the fallopian tube fimbria of women with BRCA1/2 mutations undergoing risk-reducing salpingoophorectomy10–12.