Dediduosis: An Incidental Autopsy Finding Simulating Metastatic Disease

Abstract

Abstract Casestudy Deciduosis, defined as the presence of benign decidual cell clusters outside the endometrium, is an uncommonly reported entity described in pregnant women. It represents progesterone-induced metaplasia of stromal cells, and has been reported in ovary, cervix, uterine serosa and fallopian tubes. Deciduosis has been noted very rarely in peritoneum, omentum, appendix, diaphragm, abdominal organs and pelvic lymph nodes. As an incidental finding, it must be distinguished from more ominous entities which it may resemble. Methods A 30 year old female, 29w pregnant, died from an intracranial hemorrhage. Her history was significant for Crohn’s disease and multiple sclerosis, with no previous history of malignancy. At the time of autopsy, she had had an emergency C-section and delivered a healthy male newborn. She donated multiple organs which limited our examination. However, we examined her gynecologic and aerodigestive tract completely. Several enlarged abdominal lymph nodes were identified and sampled for histologic examination. Results Gross examination of the gynecologic tract was consistent with status post cesarean section, with no other significant findings. Microscopically, one abdominal lymph node showed multiple clusters of cells with abundant amphophilic cytoplasm, small round nuclei, inconspicuous nucleoli, and prominent myxoid change, obliterating the sinusoids. Similar cells were found in subserosal locations in both ovaries, the endocervical stroma and the mesoappendix. The cells were negative for cytokeratins and calretinin, ruling out metastatic carcinoma and mesothelioma, respectively. CD68 highlighted individual sinusoidal macrophages surrounding the clusters. The cells were positive for vimentin, CD10, and progesterone receptor. These findings are consistent with deciduosis. The absence of associated endometrial-type glands excluded a diagnosis of endometriosis with decidualized endometrial stroma. Conclusion Deciduosis is a rarely reported entity that is important to recognize when dealing with suspicious cell clusters simulating metastatic disease in a pregnant woman. There are few high quality photomicrographs in medical literature, particularly for unusual locations such as lymph nodes. We believe our findings will help illustrate the morphologic appearance and immunohistochemical characteristics of this entity, and help distinguish it from more serious diseases.