Ovarian stroma is a stromal cell type typical of pancreatic mucinous cystadenocarcinoma (MCN). These cells are usually positive for estrogen and progesterone receptors, CD10, smooth muscle actin, and inhibin-α. In purely cytological specimens, the ovarian stroma of MCN is rarely captured. With the use of newer biopsy techniques such as TTNB, it can be present in samples and allows for an accurate diagnosis. Ovarian stroma has been mentioned as a potential therapeutic target. The most effective treatment for MCN is early surgical resection, but more than half of patients are diagnosed in advanced stages III and IV.