Adenomatoid tumor
Adenomatoid (Greek: glandular ) tumors are rare, benign tumors in the genital organs of both sexes. They presumably originate from cells of the mesothelium and are about 1–5 cm in size. Most often, adenomatoid tumors are localized in the area of the tube exit (in women) or in the epididymal tissue (in men). Such a tumor is very rarely found in other parts of the body. Clinically significant differential diagnoses are benign and malignant mesotheliomas and adenocarcinomas .
In terms of tissue , the tumors consist of narrow, vascular-like crevices and cysts, which are lined with cells that appear epithelial, so that a pseudoglandular (gland-like) structure is created. The coarse consistency of the tumor is caused by the collagenous, fiber-rich connective tissue that surrounds the cleft spaces or pseudocysts.
On the basis of immunohistochemical investigations, a mesothelial origin is assumed, since the nuclei of the tumor cells are positively stained with the mesothelial cell marker calretinin .