Uterine Myxoid Leiomyosarcoma with Widespread Metastases in a Cat

Abstract

Abstract. A 10-year-old domestic shorthair cat was spayed to remove bilateral ovarian masses and an enlarged uterus. Both ovaries were effaced by large, irregular, firm, glistening, white cystic masses filled with clear viscous fluid. The uterine lumen was filled with copious amounts of clear viscous fluid, and the uterus contained multiple, firm, glistening, white nodules. Histologic examination revealed an invasive spindle cell neoplasm with features of malignancy, and extensive hypocellular areas containing an alcian blue-positive myxoid matrix. Tumor cells expressed caldesmon, a-smooth muscle actin, and estrogen receptor but were negative for desmin. The animal was euthanized 1 month later because of suspected local tumor recurrence. At necropsy, the abdominal cavity contained 120 ml of mucoid ascites; multiple tumor nodules were present in the abdominal and thoracic cavities. The clinical behavior and gross, microscopic, and immunohistochemical findings established a diagnosis of myxoid leiomyosarcoma.

Multiple pathologies of the feline uterus: a case report

“…However, even in cases with aggressive clinical course, microscopically no features of severe atypia may occur, and mitotic indeces can be low. In these cases, therefore, discrimination between malignant and nonmalignant forms is based on biological behavior (Cooper et al, 2006). Similarly, in the presented case only a few areas of mild nuclear atypia and low numbers of mitotic figures were observed.…”

“…Miller et al (2003) reported that leiomyomas, but not leiomyosarcomas were positive for estrogen receptor-alpha. However, in the case of feline myxoid leiomyosarcomas weak positive nuclear reactions in some neoplastic cells have been noted (Cooper et al, 2006). Although there is no data on the presence of progesterone receptors in myometrial tumors in cats, the strong positive nuclear reaction, noted in most tumor cells in this study, may suggest the tumor cells were well differentiated.…”

“…As was done in the presented case, the myometrial derivation of leiomyoma can be confirmed using anti-desmin antibody; however, the absence of desmin does not exclude the muscular origin of a tumor. For example, some leiomyosacromas do not express desmin, but a positive immunohistochemical reaction for α-sma or Van Gieson staining is believed to confirm the muscular nature of the tumor (Cooper et al, 2006).…”

“…In cats with uterine tumors the following clinical signs are presented: abdominal mass, weight loss, anorexia, pain, and vaginal bleeding in some cases (Miller et. al., 2003;Cooper et. al.…”

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.…”