Uterine Neoplasia in 13 Cats

Abstract

Abstract. Thirteen uterine tumors were diagnosed in 13 cats and accounted for 0.29% of all feline neoplasms received during a 9.6-year period. Age at diagnosis ranged from 3 to 16 years; median 9 years. Six were Domestic Shorthair cats, and 7 were purebred cats of 5 different breeds. Eight adenocarcinomas and 1 mixed Müllerian tumor (adenosarcoma) comprised the endometrial tumors. Myometrial tumors included 3 leiomyomas and 1 leiomyosarcoma. One of the adenocarcinomas developed in the uterine stump of an ovariohysterectomized cat; the other cats were sexually intact. Concurrent mammary adenocarcinoma was diagnosed in 1 cat with uterine adenocarcinoma and in another with uterine leiomyoma. Tumors were discovered during elective ovariohysterectomy in 2 cats, but at least 3 others had experienced reproductive problems (infertility or pyometra). Five cats presented for abdominal or pelvic masses. Endometrial adenocarcinomas were positive immunohistochemically for cytokeratins and negative for smooth muscle actin (SMA); 1 of 6 cats was positive for vimentin and 4 of 8 were positive for estrogen receptor-␣ (ER␣). Adenosarcoma stromal cells were positive for vimentin and ER␣ but negative for cytokeratins and SMA. Smooth muscle tumors were positive for vimentin and SMA and negative for cytokeratins. Leiomyomas, but not the leiomyosarcomas, were positive for ER␣. Adenocarcinomas in 4 cats had metastasized by the time of ovariohysterectomy. Two other cats were euthanized 5 months after ovariohysterectomy; at least one of these cats had developed an abdominal mass that was not examined histologically. Only 2 cats with endometrial adenocarcinoma had disease-free intervals longer than 5 months after surgery. Metastasis was not detected in any mesenchymal tumor; however, these cats were either euthanized on discovery of the tumor or the tumor was first detected at necropsy.Endometrial adenocarcinoma, the most common uterine epithelial tumor, is rare in domestic animals other than rabbits and cattle. 26 The most common mesenchymal tumor of the uterus is leiomyoma. 28 Uterine neoplasia is seemingly rare in cats. 44 No uterine neoplasms were recorded in separate reviews of 395 7 and 621 feline tumors, 17 and only 1-4 cases of uterine neoplasia (leiomyoma, 12,38,46 adenocarcinoma, 14,43,46 adenoma, 43 leiomyosarcoma, 46 or lymphosarcoma 13 ) were found in retrospective surveys of 165-571 cats with tumors. Uterine leiomyoma has been the most common tumor in retrospective studies limited to feline genital tract neoplasia. Four leiomyomas, 2 leiomyosarcomas, and 1 endometrial adenocarcinoma comprised the uterine tumors in 1 review. 24 In another report, 8 there were 8 leiomyomas, 4 adenocarcinomas, and 3 leiomyosarcomas. In a 20-year survey, 7 leiomyomas, 1 leiomyosarcoma, and no adenocarcinomas were recorded.

Uterine Adenocarcinoma with Abdominal Metastases in an Ovariohysterectomised Cat

“…(Miller et al 2003, Cooper et al 2006, Sapierzynski et al 2009. In this case the cat was displaying signs of prolonged and recurrent oestrus despite attempted ovariohysterectomy, and had abdominal distension, weight loss and pain.…”

“…Uterine tumours are more commonly found in entire female cats, between 4 and 16 years of age (Belter et al 1968, Gil da Costa et al 2009, Meier 1956, Miller et al 2003, O'Rourke 1970, Preiser 1964, Sapierzynski et al 2009, Schmidt 1967. Only one case of uterine adenocarcinoma has been reported in an ovariohysterectomised female cat (Miller et al 2003).…”

“…Only one case of uterine adenocarcinoma has been reported in an ovariohysterectomised female cat (Miller et al 2003).…”

Multiple pathologies of the feline uterus: a case report

“…Uterine tumors are rare in cats, constituting 0.29% of feline neoplasms reported in one study (Miller et al, 2003). The most common neoplasms in this species include leiomyomas, endometrial adenocarcinomas and leiomyosarcomas, although other lesions have also been described.…”

A Spayed Female Cat with Squamous Cell Carcinoma in the Uterine Remnant

“…For improvement of prognosis, aggressive adjunctive therapies, such as chemotherapy and radiotherapy, should be considered, with the owner's consent. Uterine tumors are rare in cats, constituting 0.29% of feline neoplasms reported in one study [7], and most uterine tumors are adenocarcinomas or leiomyomas. Furthermore, there have so far been only a few reports about tumors in the uterine remnant of spayed female cats.…”