Adenomatoid Tumor in the Fallopian Tube - A Rare Case

Introduction: Adenomatoid tumors are benign mesothelial neoplasms of the fallopian tube. They are rare and are usually diagnosed incidentally in specimens sent for tubal ligation and can be confused with vascular or epithelial benign-malignant lesions. Case Presentation: Tubal segments from a 43-year-old patient who underwent tubal ligation during a cesarean section were sent to our pathology laboratory. Gross examination revealed no macroscopic lesion. Microscopic examination revealed a well-circumscribed lesion that at first glance resembled a vascular lesion lined by cuboidal or flat cells. No atypia, mitosis, or necrosis was observed. Immunohistochemical staining showed positivity for calretinin, cytokeratin, and vimentin. Based on all data, a diagnosis of adenomatoid tumor was made. Discussion: Adenomatoid tumors are generally found in the uterus and rarely in the fallopian tubes and ovaries in women. They are typically detected incidentally in patients treated for various reasons. Differential diagnosis includes benign, intermediate, and malignant conditions such as leiomyoma, lymphangioma, carcinoid, epithelioid hemangioendothelioma, malignant mesothelioma, Krukenberg tumor. Due to its localization, adnexal lesions also falls into the differential diagnosis of our case Conclusion: Adenomatoid tumors are rare, incidental findings in surgical practice. Despite their generally benign appearance, they can mimic other benign and malignant lesions due to their variable histology and atypical locations, necessitating differentiation from these conditions.