Reprod Dom Anim 41, 189–190 (2006) ISSN 0936-6768
Short Communication Endometrial Adenocarcinoma and Mucometra in a 6-year-old Alaska Malamute Dog FJ Pena, JA Gines, J Duque, V Vieitez, R Martinez –Pe´rez, L Madejo´n, I Nun˜ez Martinez, JM Moran and S Ferna´ndez-Garcı´ a Veterinary Teaching Hospital, University of Extremadura, Ca´ceres, Spain
Contents A 6-year-old female Alaska Malamute dog was presented for evaluation of abdominal enlargement referred by a local veterinarian. On the history, the owner complained of chronic abdominal enlargement initiated more than 4 months ago, reduced appetite, occasional vomiting and general dullness. He also complained of greenish mucous intermittent vaginal discharge starting 10 days ago. The bitch was chronically treated with medroxiprogesterone acetate. A laparatomy was performed and fluid in the abdomen was found and aspirated during the surgery. Also a very fluid-filled distended uterus and a mass in the distal part of the left uterine horn were found. The mass was encapsulated by the omentum, but areas of necrosis and calcification were identified. Histopathological diagnosis was endometrial adenocarcinoma.
Introduction Uterine tumours in the bitch are considered rare, accounting for only 0.4% of all canine tumours, and between 1 to 19% of all the female genital tract tumours (Johnston et al. 2001). Of those reported, the most frequent are leiomyomas representing more than the 90% of all uterine canine tumours. Other benign uterine tumours described are angiolipoleimomyma (Bosclair and Dore´ 2001), fibroma, fibroleyomioma, fibromyoma, adenoma, lypoma and endometrial polyp (reviewed by Johnston et al. 2001). Malignant uterine tumours are considered extremely rare in the bitch; however, hemangiosarcoma (Murakami et al. 2001), carcinoma (Payne-Johnson et al. 1986; Cave et al. 2002) and plasmacytoma (Choi et al. 2004) have been described. Most of the uterine diseases in female dogs are related to their reproductive physiology. Bitches show long oestrus and dioestrus phases, implying long periods of uterine exposition to estrogens and progesterone, finally conducting to cystic endometrial hyperplasia and, if the bacterial contamination of the uterine contents occurs, pyometra develops (Johnston et al. 2001). However, malignant tumoural diseases in dogs are extremely rare with very few cases described in the veterinary literature. The present report documents a clinical case of uterine adenocarcinoma and mucometra in a 6-year-old Alaska Malamute.
Case Report A 6-year-old female Alaska Malamute dog was presented for evaluation of abdominal enlargement referred by a local veterinarian. The abdominal enlargement was diagnosed as ascitis and furosemide was given by the
veterinarian. On the history, the owner complained of chronic abdominal enlargement initiated more than 4 months ago, reduced appetite, occasional vomiting and general dullness. Also, he complained of greenish mucous intermittent vaginal discharge starting 10 days ago. The bitch was continuously treated with medroxiprogesterone acetate for the last 2 years. In view of this signs, a complete physical examination, serum haematology, biochemistry and abdominal ultrasound were performed. Physical examination did not reveal anomalies other than the abdominal enlargement. Results of serum biochemistry and haematology are given in Table 1. The only remarkable findings were normocytic normochromic anaemia and an increase of total proteins, revealing the chronic evolution of the disease. Abdominal ultrasound revealed an enlarged and anechoic fluid filled uterus, showing uterine loops of about 10 cm diameter. In view of this signs and history a diagnosis of mucometra (as white blood cells counts were normal) was made and surgery was proposed. A laparatomy was performed and a few millitre of clear yellowish fluid in the abdomen was found and aspirated during the surgery. Also a very fluid-filled distended uterus and a mass of about 30 cm in diameter in the distal part of the left uterine horn was found (see Fig. 1). The mass was encapsulated by the omentum, but areas of necrosis and calcification were identified. The mass was removed as a part of the ovariohisterectomy procedure. Recovery of the bitch was rapid and uneventful. Samples of the mass and uterus were fixed in formalin and subjected to histopathological examination. Histopathological diagnosis was endometrial adenocarcinoma. The non-affected uterus showed cystic endometrial hyperplasia. Following this diagnosis, the bitch was again evaluated for the presence of metastatic disease, using thoracic radiology and abdominal ultrasonography, neither of which revealed signs compatible with the existence of metastatic disease. Preventive chemotherapy was proposed but the owner refused the option. Close follow up every 6 months was proposed then. Nine months after the surgery the bitch died because of a pulmonary metastatic disease.
Discussion Very few cases of uterine malignant tumours have been described in the veterinary literature (Payne-Johnson et al. 1986; Murakami et al. 2001; Cave et al. 2002) reflecting the very low incidence of this disease in bitches.
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Table 1. Biochemical and haematological parameters at presentation Parameter WBC RBC HGB HCT MCV MCH MCHC PLT Urea Creatinin Total proteins
Values
Reference values
12.8 · 103 ll 5.92 · 106 ll 10.4 g/dl 29.9% 50.5 fl 17.6 pg 34.8 g/dl 456 · 103 ll 28 mg/dl 1.4 mg/dl 8.2 g/dl
6–17 · 103 ll 5.5–8.5 · 103 ll 12–18 g/dl 37–55% 60–77 fl 19.5–24.5 pg 32–36 g/dl 200–500 · 103 ll 10–50 mg/dl 0.5–1.5 mg/dl 5.7–7.7 g/dl
WBC, white blood cells; RBC, red blood cells; HGB, hemoglobin; HCT, hematocrit; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; PLT, platelets.
ogenesis of the tumour. However, in a previous report, a 2-year-old bitch (Payne-Johnson et al. 1986) was treated with ethinyloestradiol and megestrol acetate and the authors pointed out the possibility that the lesion was drug related, though this possibility was not further confirmed. In the clinical case reported here, a chronic exposition to exogenous progestogens was confirmed and in relation to this, a mucometra was reported; however, whether or not the progestagen therapy was also related to the development of the uterine carcinoma remains to be addressed. A note of caution can be deduced from it. This is the second report in the veterinary literature in which a chronic exposition to progestagens is present, and although a clear cause– effect relationship cannot be demonstrated, a possible role of exogenous progestogens cannot be completely excluded. In short, a clinical case of canine endometrial carcinoma and mucometra is described, being one of the few cases described in the veterinary literature and the first one occurring in a bitch that simultaneously presented mucometra.
References
Fig. 1. Uterine mass found at laparotomy. Note also the fluid-filled distended uterus and mesenteric adhesions
The peculiarities of the bitch physiology predispose to the cystic endometrial hyperplasia or pyometra complex, if the uterine contents are colonized with bacteria. In the case we report here and in contrast to the other two cases reported so far, both pathologies of uterine adenocarcinoma and mucometra were present. The bitch was chronically treated with medroxiprogesterone acetate. Although this fact easily explains the mucometra, no relationship can be established with the path-
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[email protected]
2006 The Authors. Journal compilation 2006 Blackwell Verlag
