The results of the cysts biopsy (Figure 2) showed a histology formed by an external serous layer, a well-organized smooth muscle, and an inner layer of tubal cylindrical epithelium with small fibrous stroma papillae, no atypias, and no proliferative activity. Although some decidualized cells were present, no endometrial stroma was found. The immunohistochemistry analysis showed a positive expression for PAX8 (Box-8), CK7, and estrogen and progesterone receptors and a negative expression for CD10, calretinin, and CK20. The proliferative index with Ki67 was below 1%. The cytology showed histiocytes and scarce inflammatory cellularity. The final diagnosis was of florid cystic endosalpingiosis.