Histopathological and Immunohistochemical Characterization of Spontaneously Occurring Uterine Deciduomas in Young Adult Rats

Abstract

Uterine deciduomas were found in two female virgin rats, a 15-week-old Lewis rat and a 7-week-old Sprague-Dawley rat. The firm white nodules were located at the base of unilateral uterine horns and were approximately 6 mm and 4 mm in diameter. Histopathologically, the nodules were composed of three areas, each with a distinct type of proliferating cells: large epithelioid decidual cells with round nuclei, prominent nucleoli and abundant eosinophilic cytoplasm (antimesometrial region); compact spindle-shaped cells with oval nuclei and vacuolar cytoplasm (transitional region); and pleomorphic and spiny cells with round to oval nuclei and compact eosinophilic cytoplasm (mesometrial region). These cells proliferated in sheet-like arrangements and transformed into the other types of cells located in surrounding regions. Immunohistochemically, proliferating cells in all regions were strongly positive for proliferating cell nuclear antigen. The proliferating cells were positive for vimentin, and large decidual cells were positive for common acute lymphoblastic leukemia antigen 10, a marker of uterine interstitial cells. Large decidual cells were positive for α-smooth muscle actin and desmin, suggesting differentiation into muscular cells. Progesterone receptor was expressed in all cell types; however, estrogen receptor α was not expressed in the antimesometrial region. These extremely rare tumor-like nodules represent nonneoplastic lesions referred as decidual reactions of endometrial interstitial cells, and their biological behavior is that of a space-occupying benign tumor in young rats. Our cases might provide information as a historical control in toxicity and pharmacological studies in rats.

Hoxa-10 and Cyclin D3 Overexpression in the Decidual Reaction in a Superovulation Protocol in Young Adult C57BL/6J Mice

“…32 By contrast, no transition regions were noted between the mesometrial and antimesometrial areas of the endometrium, as previously described in rat spontaneous deciduomas. 42 Our results showed that uterine decidual cells strongly expressed desmin, which is considered one of the characteristic markers of deciduated cells, 14,17,22 but negative staining for vimentin, which is in contrast to the findings described by other authors. 42 Similar to previous descriptions regarding mouse physiological decidual changes 33 or rat spontaneous deciduomas, 42 we observed uterine natural killer cells in the decidual reaction, which may contribute to immune tolerance at the maternal-fetal interface regulating the penetration of trophoblast cells during implantation.…”

“…Histologically, in the current study, the uterine decidual reaction showed structural organization in 3 different regions, in accordance with previously described spontaneous decidual reactions in older rats 16,42 and in arachis oil-induced deciduomas in mice. 32 By contrast, no transition regions were noted between the mesometrial and antimesometrial areas of the endometrium, as previously described in rat spontaneous deciduomas.…”

“…The induced uterine decidual reaction has been previously reported in rats and mice by exposure to different hormonal treatments 12,15,21 or provocation by multiple artificial stimuli. 2,6,32,36 Grossly, in the present study, the mouse decidual reaction associated with the superovulation protocol showed a multifocal nodular pattern with uterine horn enlargement, which is similar to that observed in other induced uterine decidual reactions in mice, 12,32,37 while spontaneous uterine decidual reactions in mice 10 and rats 42 have been described as solitary nodules. Figure 10.…”

“…24 Presently, the infusion of sesame oil or blastocyst-sized ConA-coated sepharose beads, placed into the uterus on day 2.5 of pseudopregnancy, is employed to induce the decidual reaction in mice. 2,20,23,31 In contrast, the rodent spontaneous endometrial decidual reaction is an infrequent pathological process that has been reported in rats 13,16,42 and in 134-week-old female mice. 10 Cases of the pathological decidual reaction have also been reported in other mammals, such as humans 18 and monkeys.…”

<i>N</i>-Methyl-<i>N </i>-nitrosourea-induced Renal Tumors in Rats: Immunohistochemical Comparison to Human Wilms Tumors

“…Sequential sections of nodules were labeled with antibodies to pancytokeratin (CK) as an epithelial cell marker 21 , vimentin as a mesenchymal cell marker, p63 as a basal/muscular cell marker 22 , α-smooth muscle actin (SMA) and desmin as muscular cell markers, S-100 as a Schwann cell and adipocyte marker 21 , CD57 as a renal pelvic epithelial cell/Wilms tumor cell marker 23 , CD117/c-kit as a gastrointestinal stromal tumor/Wilms tumor cell marker 24 and Wilms tumor 1 protein (WT1) and β catenin as Wilms tumor cell marker 25 , 26 . Detailed staining protocols for all antibodies are listed in Table 1…”