A 45 year old woman develops abdominal and pelvic discomfo. Physical examination reveals a large mass in the right lower quadrant, which is surgically resected. The mass consists of a large (25 cm) cystic sac containing thick mucinous fluid within a thin wall. On careful inspection, the pathologist finds an area of increased thickness in the cyst wall, which is sampled for histology. Microscopically, the tumor appears to be composed mostly of a single layer of nonciliated columnar cells arranged in papillary projections. The thickened area, however, displays stratification of epithelial cells, increased cytologic atypia, and high mitotic activity. Neveheless, no stromal invasion is found. Which of the following is the most likely diagnosis?
Classification of ovarian tumors, like testicular tumors, is based on putative cell of origin. Thus, ovarian tumors can be divided into neoplasms of germ cells,surface epithelium, or stromal origin. Two thirds of all ovarian neoplasms derive from the surface (coelomic) epithelium. These cystic tumors may contain clear serous fluid or turbid mucinous fluid. Depending on whether a tumor is benign or malignant, surface epithelium tumors can be differentiated into serous cystadenoma or cystadenocarcinoma, and mucinous cystadenoma or cystadenocarcinoma. Borderline tumors are intermediate cases in which the epithelial lining shows malignant features (cytologic atypia and architectural disorganization) in the absence of stromal invasion. Thus, microscopic features of the ovarian tumor in this case are consistent with a borderline mucinous tumor. Mucinous cystadenocarcinoma shows obvious signs of malignancy, including foci of invasion of the stroma within the cystic wall. Mucinous cystadenoma is a cystic tumor with a mucin-rich fluid content. The epithelial lining is similar to intestinal or cervical epithelium, ie, a single layer of columnar cells with apical mucin and no cilia. Serous cystadenocarcinoma is the most frequent malignant ovarian tumor. Its epithelial lining is composed of columnar cells showing atypia and crowding. By definition, stromal invasion is present. Ref: Levy G., Purcell K. (2013). Chapter 50. Premalignant & Malignant Disorders of the Ovaries & Oviducts. In A.H. DeCherney, L. Nathan, N. Laufer, A.S. Roman (Eds), CURRENT Diagnosis & Treatment: Obstetrics & Gynecology, 11e.
Borderline mucinous tumor
Mucinous cystadenocarcinoma
Mucinous cystadenoma
Serous cystadenocarcinoma