The results of this study strongly suggest that dysregulation of the Wnt/β-catenin pathway plays a fundamental role in the pathogenesis of ovarian MCST.
Since our first description of the microcystic stromal tumor (MST) of the ovary, a rare and distinctive neoplasm with a definitional, usually striking microcystic pattern and a CD10+/vimentin+/inhibin-/calretinin- immunophenotype, 3 examples with β-catenin nuclear localization, and CTNNB1 mutation have been reported.
We report four ovarian neoplasms in patients aged 45, 56, 61 and 71 years with the characteristic immunophenotype of microcystic stromal tumour (diffuse nuclear positivity with beta-catenin, cyclin D1 and WT1; diffuse cytoplasmic positivity with CD10; negative inhibin, calretinin, oestrogen receptor and progesterone receptor).