Diagnosis of multicentric lymphosarcoma in dogs

1 morbidity and clinical symptoms

A pug, female, more than six years old, was raised by a dog household in Jinzhou, Liaoning Province. in late January 2004, it was found that food intake decreased gradually, mental depression and weight loss; after the addition of cardiolysis, multivitamins, multi-enzyme tablets and lactobacillus, there was no obvious curative effect, and there was no obvious curative effect after treatment with ribavirin, cefotazole and roxithromycin.

About 3 months after the onset of the disease, the dog's body weight decreased from 6kg to 4.3kg, physical weakness, dyspnea, increased pulse, polyuria, sometimes vomiting, abdominal circumference obviously enlarged, visible mucous membrane pale, palpation of abdomen, hematological examination, red blood cell count, thrombocytopenia, leukocyte classified count lymphocytes and adult lymphocytes significantly increased. After the above examination, it was preliminarily determined that the abdominal organ of the diseased dog was enlarged or a tumor was formed in the abdominal cavity.

2abdominal exploration and splenectomy

2.1 Instruments, drugs and supplies are generally needed for laparotomy.

Methods the dogs were anaesthetized on their back in Baoding. On the midline of the abdomen, the small point of the line between the sword cartilage and the umbilical cord was the midpoint of the incision, the 3~4cm of the abdominal wall was cut first, and the abdominal organs were explored with fingers, and it was found that the spleen was highly enlarged and solid, and the ascites in the abdominal cavity was increased, reddish yellow and slightly turbid. The ascites smear was inoculated with Agar medium, then the ascites was sucked out with a sterilized syringe, the incision was enlarged, the spleen was pulled out, the splenic artery and splenic vein were separated and ligated triple ligation, cut in the middle of the ligation line, then cut the splenogastric ligament and splenorenal ligament, and dissociated the spleen. Then, the blood vessels of abdominal bleeding were compressed or sutured to stop bleeding, but because of the dog's high weakness and anemia, the blood coagulation decreased. The brittleness of the celiac vascular wall increased, it was difficult to stop bleeding, excessive bleeding, did not wait to clean the abdominal cavity, suture the abdominal wall, the sick dog died.

3The change of dissection.

The main changes in diseased dogs were as follows: highly enlarged spleen, long 26cm, 9cm at the widest part of spleen head, width of spleen tail 7cm, thickness 3~5cm, spleen weight 600g, spleen capsule incomplete, uneven, bleeding focus, necrosis focus, fragile texture, gray-white and gray-red section color mottled, structure texture unclear; liver slightly enlarged, brittle, gray-white small lesions on the surface, gallbladder wall thickening Mandibular lymph nodes, inguinal lymph nodes, mesenteric lymph nodes swollen, milky white or grayish brown, hard texture but wet section, fuzzy structure: pericardial cavity and abdominal cavity effusion.

4 bacteriological examination

Ascites, liver blood, heart blood, spleen blood and lymph node smears were taken by aseptic method and inoculated with common Agar medium: the smears were stained with Gram's and Gibbs staining and examined under microscope. The culture medium was incubated in a 37 ℃ incubator for 24 hours.

Results: no microorganism was found in the smear and no colony formation was found in the culture medium.

5 Animal inoculation

5.1 equipment and animal routine animal inoculation equipment, 30 mice.

5.2 the liver, spleen and lymph nodes were taken to make suspension.

5.3 methods the disease materials were divided into two kinds: disease material suspension and double-antibody treatment. 10 mice were inoculated intraperitoneally, and 10 mice were used as blank control group for one week.

5.4 results there was no disease and death in both the control group and the experimental group.

6 histopathological examination

6.1 spleen, lymph nodes, liver of diseased dogs, 10% formalin, Hypo E stain (hematoxylin ~ eosin stain).

Methods according to the requirements of pathological tissue section materials, the spleen, lymph nodes and liver of diseased dogs were fixed with 10% formalin for 24 hours, then washed for 24 hours, then cut into 1cm × 1cm × 0.5cm-sized tissue blocks, and then went into the process of dehydration, transparency, wax dipping, embedding and slicing to make paraffin sections. The paraffin sections were stained with hematoxylin-eosin staining and finally sealed and labeled.

6.3 observation spleen, lymph nodes and liver tissue sections were observed under 10 × 20 and 10 × 40 times microscope.

6.3.1 the structure of spleen and spleen is disordered, the boundary between medulla and cortex is unclear, lymphocytes and lymphoid cells are diffusely distributed, especially around arterioles and trabecular arteries, the number of cells is denser, the morphology of tumor cells is less, the nucleus is oval, round and quadrilateral, the nuclear membrane is obvious, chromatin is scattered or clumped, nucleolus is obvious, mitosis is more common. There are few reticular cells and macrophages in splenic tissue, and necrotic foci composed of pink and unstructured necrotic tissue can be seen in many places.

6.3.2 the tumor cells of lymph nodes showed diffuse proliferation, and the morphology of tumor cells was similar to that of spleen.

6.3.3 liver tumor cells were mainly distributed around the portal area, and some tumor cells were also distributed around the central vein.

7 diagnosis result

7.1 the clinical symptoms of the diseased dogs were emaciation, anemia, enlarged abdominal circumference, solid swelling in the abdominal cavity by palpation, and ineffective treatment with antibiotics, which was judged to be a chronic wasting disease.

7.2 abdominal exploration and autopsy showed that the spleen was highly enlarged, the lymph nodes were swollen, and the parenchyma on the surface of the liver showed small gray lesions.

7.3 the diseased dog materials were negative by bacteriological examination and animal inoculation.

7.4 Hematological examination showed that the red blood cell count, thrombocytopenia and the number of lymphocytes and adult lymphocytes increased significantly.

7.5 the histopathological examination of spleen, lymph nodes and liver lesions showed lymphoblastoma cell proliferation.

7.6 according to the above results, the dog was diagnosed as multicentric, lymphoblastic lymphosarcoma.

8 discussion

8.1 according to the anatomical site, canine lymphosarcoma can be divided into multicentric type and digestive tract type, and according to the morphology of tumor cells, it can be divided into lymphoblastic (lymphoblastic), juvenile lymphocytic and lymphocytic, stem cell and histiocytic types. The disease is a common tumor in dogs, but it is rarely diagnosed clinically. through a series of diagnostic methods, we diagnosed this case as multicentric, lymphoblastic lymphoid sarcoma.

8.2 multicentric lymphosarcoma in dogs is mainly found in lymph nodes, spleen and liver, but this case is characterized by high splenomegaly, which is rare in clinical practice.

8.3 in addition to lymphosarcoma, canine splenomegaly can also be seen in other tumors, tuberculosis and splenitis, which should be distinguished by histopathological examination and other diagnostic methods.

8.4 there is no effective method for the treatment of lymphoid nodules in dogs. Can be treated with prednisone or dexamethasone, cyclophosphamide, phenylbutyrate nitrogen mustard and folic acid antagonists (such as aminomethine), can relieve symptoms to a certain extent, but an overdose of these drugs will cause poisoning, purpura and fatigue, and so on. At this time, the drug should be stopped for 10 to 14 days, and then decide whether to continue to take the drug according to the condition; but it is difficult to cure, the sick dog generally has no treatment value.

8.5 Lymphosarcoma is a malignant tumor, and its causes are complicated. In terms of prevention, genetic tendency should be excluded, daily feeding management should be strengthened, long-term use and contact with harmful food, drugs and environment should be avoided, and various chronic diseases should be prevented and treated actively.