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Praca oryginalna Original paper
The enlarged size of the abdominal cavity is a symp-tom causing worry for pet owners. One of the causes of the disorder may be enlargement of liver, i.e. hepa-tomegaly. The liver, being the central organ of meta-bolism, performs several roles in the body. It is res-ponsible for the synthesis and metabolism of proteins, lipids, carbohydrates, hormones and drugs as well as being a place where lipids transported via the hepatic portal vein are metabolized. Moreover, the liver carries out detoxification to decompose substances that are harmful to the body and stores vitamins and minerals.
The objective of the study was to determine the most frequent histopathological changes in all the animal livers in the research material obtained from the Lublin Province area during 2005-2009.
Material and methods
The study material included 119 livers collected post mortem and ante mortem from farm animals, furry animals, dogs and cats from the Lublin province during 2005-2009, to be examined in the Department of Pathological Anatomy of the University of Life Sciences in Lublin. The livers were evaluated macroscopically and microscopically. The
material was fixed in 4% buffered formalin, then dehydra-ted and paraffin-embedded. The 4-micron-thick sections were stained with haematoxylin and eosin (HE). In the case of dogs and cats, animal gender and age were taken into account.
Results and discussion
During five years 119 cases of histopathological changes in the livers of animals were examined. The livers from poultry accounted for 10.92% of the studied material and hepatonecrosis was diagnosed in 76.92% of the material, while hepatic congestion in 23.08% of the cases. A dominant lesion proved to be hepatonecrosis, recognized in 40% of the examined pigs, followed by hepatic cirrhosis and adipose dege-neration (Fig. 2). Next, hepatocytes are filled with multiple fat droplets that eventually coalesce into one big drop, which pushes the nucleus aside. Conse-quently, hepatocytes are laden and hepatic trabeculae deformed. There may also occur some irreversible changes in the nucleus, like pycnosis, chromatorrexis, chromatolysis as well as karyorrehesis. The livers of foxes constituted 7.56% of the total study material and 66.7% of the samples showed necrosis, while in 33.3%
Pathomorphological evaluation
of changes in the livers of animals
from the Lublin province in 2005-2009
JACEK PIÓRKOWSKI, ZBIGNIEW NOZDRYN-P£OTNICKI
Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Life Sciences, 30 G³êboka St., 20-612 Lublin, Poland
Piórkowski J., Nozdryn-P³otnicki Z.
Pathomorphological evaluation of changes in the livers of animals from the Lublin province in 2005-2009
Summary
The research material comprised the livers collected post mortem and ante mortem from dogs and cats, as well as farm animals, in the Lublin Province during 2005-2009.The material fixed in 4% buffered formalin was subsequently dehydrated and paraffin-embedded. The 4-micron-thick sections were stained with haematoxylin and eosin (HE). The most pathological changes in dogs and cats had occurred in animals over 11-years-of-age. Angiosarcoma and hepatocellular carcinoma were the most frequent neoplastic changes reported in these animals. This is due to significant pollution of the urban environment where most of these animals came from. Nitrosamines and chloral hydrate play a significant role here. Adipose degeneration and necrosis predominated among the non-neoplastic lesions recognized in all animals is often due to dietary errors committed by pet owners. The influence of animal viral cirrhosis of the liver is not as well understood in animals as in humans and requires further study.
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fatty degeneration was observed. The livers collected from cats constituted 4.2% of the total research mate-rial for examination, and within it 20% was diagnosed with adipose degeneration, congestion, jaundice and leukemia, angiosarcoma. The livers from rabbits sub-mitted to examination comprised 3.36% of the total study material and in the prevalent majority, namely 75%, a hepatic form of coccidiosis was recognized, whereas in 25% fatty degeneration. The study material obtained from sheep made up 3.36% of total material and in 50% of this material necrosis was diagnosed, whereas fatty degeneration and hydropic degeneration in 25% each. The livers taken from horses constituted 2.52% of the total material and adipose degeneration, floccular degeneration and hepatic congestion com-posed 33.3% of this share each. The livers from minks, cows accounted for 2.52%, 1.28% of total examined material, respectively, and the only change noted was fatty degeneration. The vast majority comprised the material taken from 50 cases of dogs that accounted for 42.02% of the total number of animals under study. Adipose degeneration of the liver made up the prevailing majority and constituted 28% of dog cases. A slightly lower percentage, i.e. 24% pertained to hepatic congestion. Whereas, hepatonecrosis was recognized in 12% and hepatic cirrhosis in 10% of the examined dogs. As for the non-neoplastic changes, the lowest percentage was established for hemosiderosis and jaundice, which reached 6% each, as well as for hydropic degeneration 4%. The malignant changes in the liver were reported in 5 cases that made up 10% of the studied dogs. In angiosarcoma, parenchyma was composed of endothelial cells that formed various spaces filled with erythrocytes. A high nuclear/cyto-plasmic ratio was also noted. Another malignant cancer was hepatocellular carcinoma consisting of anaplastic cells infiltrating into the connective tissue. The cells were characterized by an elongated shape, frequently pleomorphic, with hyperchromatic nuclei
(Fig. 1). Evaluation of the anatomopathological changes in relation to the age of dogs and cats indicates that the vast majority of them occurs in the oldest animals aged 11-15 years, which comprises 47.2% of the total of animals examined. Younger animals at 6-10-years-of--age showed anatomopathological changes, if any, in 29.09% of the studied animals, whereas those aged 3-5 years and 0-2 years in 18.8% and 5.46%, respec-tively, of the studied animals. Regarding animal gen-der, the anatomopathological changes were reported in 31% of females and 69% of males.
As a general rule, initial clinical examination allows for prompt detection of any liver disease, whereas blood cell morphology performed to evaluate the levels of liver function enzymes commonly shows the direction of the further diagnostic testing and therapeutic proce-dure. Implementation of the advanced imaging moda-lities that become more clinically available have opened up new multi-directional diagnostic opportunities for veterinarians, who use not only RTG and US techno-logies but more often novel imaging methods, such as computer tomography(CT) and magnetic resonance imaging (MRI) (1). The sensitivity of this testing is 100% and the specificity 90% for differentiation be-tween malignant and benign lesions (3); nevertheless, this diagnostic tool is rarely used in veterinary medicine. However, it should be considered owing to potential incidence of liver cancer, especially in mature aging dogs and cats. Differential diagnostics should rule out such cases as: liver abscesses, diffuse enlargement, edema and, primarily, ascites. What should deserve special notice from a veterinarian is an elevated level of liver enzymes activity, as that may imply the pre-sence of primary or secondary carcinoma. A definitive diagnosis is based on histopathological evaluation, yet the studies performed in the given region provide much valuable information concerning a number of patho-logical processes detected there correlated with animal age and species (6, 14). Histopathological lesions in Fig. 1. Hepatocellular carcinoma. Stain (HE). Magnification
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the liver, both diffuse and focal, are often reported in animals (3, 6, 12). These types of pathological changes require the differentiation of neoplastic lesions from non-neoplastic ones. It commonly happens that ani-mals with an ongoing advanced cancer process within the liver and recognized by diagnostic laparatomy are euthanized without cancer type identification.
As for animals, it was found that gastrointestinal tract cancer accounts for 5%-10% of all canine cancers and its nature, as usual, is malignant (4, 7, 11, 14). The most common sites of hepatocellular carcinoma (HCC) metastases include regional lymph nodes, bone mar-row, adrenals and lungs (5, 10). The system of macro-scopic classification includes three major types of HCC, i.e. well defined solitary tumor (massive form),
poorly marginated, infiltrative pattern (diffuse form) and multiple discreet bumps (nodular form).This carcinoma shows a high tendency to invade portal vein branches, tumor cells exhibit trabecular or lobular arrangement pat-terns and are pleomorphic (trabecular growth pattern). Occasionally in the cytoplasm of well differentiated cells, glycogen, bile or lipids can be observed (pseudoglandular pattern). A hi-stologic variant of HCC, fibrolamellar carci-noma (FLC), is characterized by large poly-gonal tumor cells, separated into cords by thin multilamellated fibrous strands. Other tumors of high-grade histologic form are angio-sarcomas, which are derived from vascular or lymphatic endothelium and most commonly located in the liver, spleen, heart and skin. These organs are most frequently affected by angiosarcomas due to their intensive vascula-rization (2, 8). These malignant sarcomas usually occur in older dogs beyond 10 years, as it was observed both in the present studies and that of other authors (2, 8). Unlike human angio-sarcoma, no single predilection for the incidence of the sarcoma in animals is known and it still presents a challenge. Interestingly, genetic predisposition has become a recent focus in the study of tumor angio-genesis (15). Increased susceptibility of humans to HCC is attributed to earlier liver infections caused by the hepatitis B virus (HBV), rarely type C (HCV), and puts people at high risk of death from cirrhosis. In the course of type B hepatitis, necrotic-inflammatory lesions are developed with progressive regeneration that promote potential gene mutation. A vital role for both humans and animals is performed by environmen-tal hepatocarcinogens, among others chloral hydrate formed as a by-product through disinfection of water Tab. 1. Number and type of anatomopathological changes in each animal species
r e b m u n d n a s e i c e p S g o D 0 5 C5at Mi3nk Ra4bbti Ho3rse Sh4eep F9ox Po1u3lrty P1i0g C1o7w T1o1ta9l n o it a r e n e g e d e s o p i d A 14 1 3 1 1 1 3 3 17 45 n o it a r e n e g e d s u o t a m y h c n e r a P 1 1 n o it a r e n e g e d c i p o r d y H 2 1 3 n o it s e g n o C 12 1 1 3 17 s i s o r e d i s o m e a H 3 3 s i s o r c e N 6 2 6 10 4 28 s i s o h rr i C 5 3 8 e c i d n u a J 3 1 4 s i s o i d i c c o C 3 3 a m o n i c r a c r a l u ll e c o t a p e H 2 2 a i m e k u e L 1 1 a m o c r a s o i g n A 3 1 4
Tab. 2. Incidence of each pathomorphological change in dog and cat in relation to gender and age
r e d n e g d n a s r a e y n i e g A 2 -0 3-5 6-10 11-15 n o it a r e n e g e d e s o p i d A 1 1 1 3 2 7 n o it a r e n e g e d s u o t a m y h c n e r a P n o it a r e n e g e d c i p o r d y H 2 n o it s e g n o C 2 4 2 3 2 s i s o r e d i s o m e a H 3 s i s o r c e N 1 1 2 2 s i s o h rr i C 5 e c i d n u a J 1 1 2 s i s o i d i c c o C a m o n i c r a c r a l u ll e c o t a p e H 2 a i m e k u e L 1 a m o c r a s o i g n A 3 1
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and nitrozoamine (13). The results of animal tests showed aphlotoxin B-1 to be among the most potent carcinogens known. It is also noteworthy that dietary deficiency of choline and methionine results in the loss of methyl groups within DNA, which exerts a pro-found influence on the expression of genes encoding hepatocyte proliferation and differentiation. Moreover, a higher incidence rate reported among men is attribu-ted to the activity of testosterone derivatives, but this has not been confirmed in animals. The amazing unique regenerative capacity of the liver reaching as high as 75% allows for the introduction of appropriate multi-directional therapeutic interventions including both surgical procedure and, if possible, chemotherapy (9, 12).
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Corresponding author: Dr. Jacek Piórkowski PhD, Department of Pathological Anatomy, Faculty of Veterinary Medicine University of Life Sciences, 30 G³êboka St., 20-612 Lublin, Poland; e-mail: jacek.piorkowski @up.lublin.pl
