Four major hypotheses have been postulated regarding the histogenesis of adenomatoid tumours over the years including endothelial, mesonephric, mesothelial and mullerian epithelium origin.1,9 Masson et al. proposed mesothelial origin of these tumours for the first time in 1942, using macroscopic and microscopic finding of serosal surface origin and electron microscopy findings.10,11 The theory was proven by Stephenson and Mills in 1986 by using electron microscopy, mucin histochemical and immunohistochemical features.9 Here, MUC5AC is linked to neoplasm.