Correlation of ultrasonographic appearance of lesions and cytologic and histologic diagnoses in splenic aspirates from dogs and cats: 32 cases (2002-2005)

OBJECTIVE: To determine the accuracy of cytologic diagnosis, compared with histologic diagnosis, in determination of disease in ultrasound-guided fine-needle aspirates of splenic lesions. DESIGN: Retrospective study. SAMPLE POPULATION: Splenic specimens from 29 dogs and 3 cats. PROCEDURES: Records were searched for dogs and cats that had undergone ultrasound-guided splenic aspiration. Criteria for inclusion were ultrasonographic identification of splenic lesions and cytologic and histologic evaluation of tissue from the same lesion. Cytologic samples were obtained by fine-needle aspiration, and histologic specimens were obtained via surgical biopsy, ultrasound-guided biopsy, or necropsy. RESULTS: Cytologic diagnoses corresponded with histologic diagnoses in 19 of 31 (61.3%) cases and differed in 5 of 31(16.1%) cases, and 1 aspirate was inadequate for evaluation. In 7 of 31 (22.6%) cases, histologic evaluation of tissue architecture was required to distinguish between reactive and neoplastic conditions. On the basis of histologic diagnosis in 14 animals with nonneoplastic conditions, the cytologic diagnosis was correct in 11 cases, not definitive in 2 cases, and incorrect in 1 case. In 17 animals with malignant neoplastic diseases, the cytologic diagnosis was correct in 8 cases, not definitive but consistent with possible neoplasia in 5 cases, and incorrect in 4 cases. Multiple similar-appearing nodules were significantly associated with malignancy, whereas single lesions were more often benign. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided aspiration of splenic lesions is a minimally invasive tool for obtaining specimens for cytologic evaluation. Although cytologic diagnoses often reflect histologic results, if missampling or incomplete sampling occurs or tissue architecture is required to distinguish between reactive and neoplastic conditions, accurate diagnosis with fine-needle aspiration may not be possible.     

Comparison of Fine-Needle Aspiration and Surgical-Tissue Biopsy in the Diagnosis of Canine Brain Tumors

OBJECTIVE: To compare the diagnoses obtained using fine-needle aspiration (FNA) and surgical-tissue biopsy of focal cerebral masses with the histologic diagnoses obtained via necropsy. STUDY DESIGN: A prospective case series. SAMPLE POPULATION: Ten client-owned adult dogs of various breeds. All dogs had clinical signs of cerebral disease and had a focal brain mass identified using magnetic resonance imaging; all were eventually euthanatized. METHODS: Immediately after euthanasia, the brains were removed en bloc from the cranial cavity. FNAs were obtained from each mass using a 22-gauge hypodermic needle and a 12-mL syringe. Cytologic preparations were made from each aspirate. A 14-gauge Tru-cut biopsy needle was used to obtain a core tissue sample from each mass. The biopsy specimens were fixed in 10% buffered formalin and submitted for histologic evaluation. The brains were similarly fixed and stained. Six-micrometer-thick transverse sections of the brain were examined microscopically. RESULTS: Neoplasia was confirmed in all dogs histologically in the 6-microm transverse sections. Four meningiomas, 2 astrocytomas, 2 oligodendrogliomas, 1 pituitary adenocarcinoma, and 1 neurofibrosarcoma were identified. FNA correctly identified all of the masses as neoplastic. Cytologic diagnoses correlated with the histologic interpretation in 5 of the masses (50%). Tru-cut biopsy specimens identified all 10 masses as neoplastic; in 9 of the 10 (90%), the diagnosis correlated with the histologic diagnosis. CONCLUSIONS AND CLINICAL RELEVANCE: FNA is a sensitive method that can be used to determine the presence of neoplasia in the brain, but is not as definitive as the Tru-cut biopsy in determining the specific type of cerebral neoplasm.     

Renal biopsy of dogs and cats

Renal diseases are common in dogs and cats. Renal biopsy may be required during the evaluation of the patient to establish a definitive diagnosis, determine the severity of the lesion and formulate an optimal treatment plan. Renal biopsy specimens can be collected via several methods. Percutaneous techniques are performed with ultrasound guidance in both dogs and cats or blindly in cats. If ultrasound guidance is not available, the keyhole technique can be used in dogs. Biopsy can also be performed using laparoscopy or surgery. While complications can arise with any of these techniques, complications are less frequent when an experienced operator uses proper technique. Renal biopsy specimens must be processed and evaluated appropriately if consistent and accurate diagnoses are to be rendered. The article summarizes patient selection and evaluation, renal biopsy techniques, expected complications of renal biopsy, and appropriate processing and evaluation of the renal biopsy specimen.     

Quality of tissue specimens obtained endoscopically from the duodenum of dogs and cats

OBJECTIVE: To evaluate quality of duodenal tissue specimens obtained endoscopically from dogs and cats and submitted to 1 of 2 diagnostic laboratories for evaluation. DESIGN: Case series. SAMPLE POPULATION: Slides from 50 consecutive canine and 50 consecutive feline endoscopically obtained duodenal tissue specimens submitted to laboratory 1 and 49 consecutive canine and 46 consecutive feline specimens submitted to laboratory 2. PROCEDURE: Slides were examined independently by 3 investigators, and each tissue piece on each slide was classified as clearly inadequate, questionable, or clearly adequate on the basis of 4 criteria. An overall score was then assigned to the slide. RESULTS: Slides from laboratory 1 were more likely to be scored as clearly adequate and less likely to be scored as clearly inadequate than slides from laboratory 2. Clearly adequate slides from laboratory 1 had a higher number of clearly adequate pieces of tissue than did clearly adequate slides from laboratory 2. Slides scored as clearly adequate had a higher number of individual tissue pieces than did slides scored as clearly inadequate. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the quality of endoscopically obtained duodenal tissue specimens submitted to laboratories can vary, possibly because of differences in experience of individuals collecting biopsy specimens. Results suggest that at least 8 individual tissue pieces should be submitted when performing endoscopic biopsy of the duodenum in dogs and cats.     

Liver glutathione concentrations in dogs and cats with naturally occurring liver disease

OBJECTIVE: To determine total glutathione (GSH) and glutathione disulfide (GSSG) concentrations in liver tissues from dogs and cats with spontaneous liver disease. SAMPLE POPULATION: Liver biopsy specimens from 63 dogs and 20 cats with liver disease and 12 healthy dogs and 15 healthy cats. PROCEDURE: GSH was measured by use of an enzymatic method; GSSG was measured after 2-vinylpyridine extraction of reduced GSH. Concentrations were expressed by use of wet liver weight and concentration of tissue protein and DNA. RESULTS: Disorders included necroinflammatory liver diseases (24 dogs, 10 cats), extrahepatic bile duct obstruction (8 dogs, 3 cats), vacuolar hepatopathy (16 dogs), hepatic lipidosis (4 cats), portosystemic vascular anomalies (15 dogs), and hepatic lymphosarcoma (3 cats). Significantly higher liver GSH and protein concentrations and a lower tissue DNA concentration and ratio of reduced GSH-to-GSSG were found in healthy cats, compared with healthy dogs. Of 63 dogs and 20 cats with liver disease, 22 and 14 had low liver concentrations of GSH (micromol) per gram of tissue; 10 and 10 had low liver concentrations of GSH (nmol) per milligram of tissue protein; and 26 and 18 had low liver concentrations of GSH (nmol) per microgram of tissue DNA, respectively. Low liver tissue concentrations of GSH were found in cats with necroinflammatory liver disease and hepatic lipidosis. Low liver concentrations of GSH per microgram of tissue DNA were found in dogs with necroinflammatory liver disease and cats with necroinflammatory liver disease, extrahepatic bile duct occlusion, and hepatic lipidosis. CONCLUSIONS AND CLINICAL RELEVANCE: Low GSH values are common in necroinflammatory liver disorders, extrahepatic bile duct occlusion, and feline hepatic lipidosis. Cats may have higher risk than dogs for low liver GSH concentrations.     

NON-CARDIAC THORACIC ULTRASOUND IN 75 FELINE AND CANINE PATIENTS

The purpose of this study was to describe the ultrasonographic appearance of non-cardiac diseases of the small animal thorax. Ultrasound images from a total of 75 animals (26 cats and 49 dogs) were compared to cytologic, histopathologic, and necropsy findings. Clinical diagnoses included neoplasia of the mediastinum, pleura, or lungs (43); idiopathic mediastinal cyst (3); diaphragmatic or peritoneopericardial hernia (4); lung lobe torsion (1); pulmonary eosinophilic infiltrates (1); and idiopathic, chylous, congestive heart failure, or lymphangiectasia associated pleural effusion (14). In the remaining 9 patients, a definitive diagnosis was not obtained. Ultrasound-guided fine needle aspirate was performed in 56 patients; 1 of these also had an ultrasound-guided tissue core biopsy. Of the fine needle aspirates, 51 (91%) were diagnostic. Ultrasound examination, particularly when accompanied by guided tissue sampling, can be a valuable tool in the diagnosis of non-cardiac intrathoracic lesions.     

Sensitivity and specificity of methods of assessing the regional lymph nodes for evidence of metastasis in dogs and cats with solid tumors

OBJECTIVE: To determine sensitivity and specificity of physical examination, fine-needle aspiration, and needle core biopsy of the regional lymph nodes for evidence of metastasis in dogs and cats with solid tumors. DESIGN: Case series. ANIMALS: 37 dogs and 7 cats. PROCEDURE: Regional lymph nodes were evaluated by means of physical examination (palpation), fine-needle aspiration, and needle core biopsy. Results were compared with results of histologic examination of the entire lymph node, the current standard. RESULTS: Tumors included 18 sarcomas, 16 carcinomas, 7 mast cell tumors, and 3 other tumors. Carcinomas were more likely to have metastasized to the regional lymph node (7/16 animals) than were sarcomas (2/18). Sensitivity and specificity of physical examination were 60 and 72%, respectively. Sensitivity and specificity of cytologic examination of fine-needle aspirates were 100 and 96%, respectively. Sensitivity and specificity of histologic examination of needle core biopsy specimens were 64 and 96%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that fine-needle aspiration may be a sensitive and specific method of evaluating the regional lymph nodes in dogs and cats with solid tumors, because results correlated well with results of histologic examination of the entire lymph node. Physical examination alone was not a reliable method and should not be used to decide whether to aspirate or biopsy the regional lymph nodes.     

Comparison of endoscopic and full-thickness biopsy specimens for diagnosis of inflammatory bowel disease and alimentary tract lymphoma in cats

OBJECTIVE: To evaluate the accuracy of endoscopic biopsy (EB) specimens for diagnosis of alimentary tract lymphosarcoma in cats. DESIGN: Prospective study. ANIMALS: 22 cats with inflammatory bowel disease (IBD) or alimentary tract lymphosarcoma. PROCEDURES: Endoscopic biopsy specimens were obtained during endoscopy of the stomach and duodenum immediately prior to laparotomy or laparoscopic surgery, during which full-thickness biopsy (FTB) specimens were obtained. Accuracy of histopathologic diagnoses was compared between EB and FTB specimens. RESULTS: Lymphosarcoma was diagnosed in 10 cats on the basis of FTB specimens. Lymphosarcoma was detected in the jejunum and ileum in all 10 cats, in the duodenum in 9 cats, and in the stomach in 4 cats. In the same 10 cats, EB findings indicated a diagnosis of lymphosarcoma in 3 cats and were suggestive but inconclusive for lymphosarcoma in 3 cats. Lymphosarcoma was correctly diagnosed via gastric EB specimens in 3 of the 4 cats with gastric lymphosarcoma but evaluation of EB specimens led to an incorrect diagnosis of IBD in 4 cats with small intestinal lymphosarcoma. CONCLUSIONS AND CLINICAL RELEVANCE: EB specimens were useful for diagnosis of gastric lymphosarcoma but were not adequate for differentiating between IBD and lymphosarcoma in the small intestine. Because the most common sites of alimentary tract lymphosarcoma in cats are the jejunum and ileum, FTB specimens of those sites should be obtained via laparotomy or laparoscopy for accurate diagnosis. Laparoscopy may be a minimally invasive alternative to endoscopy and laparotomy for obtaining diagnostic biopsy specimens.     

A comparison between the cytological and histological characteristics in thirteen canine and feline thymomas

Cytological smears and histological sections collected from histologically diagnosed cases of thymoma in nine dogs and four cats were reviewed. Most of the histological features were apparent in the cytological specimens with two notable differences. The epithelial component was underestimated and Hassal's corpuscles were not observed using Wright's-stained cytological preparations. Features of thymoma were recognized in seven of the nine cases in which fine needle aspiration biopsy was done. Therefore, cytology, and specifically fine needle aspiration biopsy, has the potential to be a useful aid in the rapid diagnosis of canine and feline thymomas.     

Renal biopsy: a retrospective study of methods and complications in 283 dogs and 65 cats

Renal biopsy often is required to establish a definitive diagnosis in dogs and cats with renal disease. In this retrospective study, we determined the complications of renal biopsy as well as factors that may be associated with development of complications and procurement of adequate renal biopsy specimens in 283 dogs and 65 cats. Data extracted from medical records at 4 institutions were evaluated using logistic regression. Proteinuria was the most common indication for renal biopsy in dogs. Complications were reported in 13.4 and 18.5% of dogs and cats, respectively. The most common complication was severe hemorrhage; hydronephrosis and death were uncommon. Dogs that developed complications after renal biopsy were more likely to have been 4 to < 7 years of age and > 9 years, to weigh < or = 5 kg, and to have serum creatinine concentrations > 5 mg/dL. The majority of biopsies from both dogs (87.6%) and cats (86.2%) were considered to be of satisfactory quality. Biopsies from dogs were more likely to be of high quality if they were obtained when the patient was under general anesthesia and more likely to contain only renal cortex if they were obtained by surgery. We concluded that renal biopsy is a relatively safe procedure, with a low frequency of severe complications. Hospital practices and patient variables have the potential to impact both the quality of the specimen obtained and the rate of complications.     

Use of thoracoscopy to determine the etiology of pleural effusion in dogs and cats: 18 cases (1998-2001)

OBJECTIVE: To assess use of thoracoscopy to determine causes of pleural effusion in dogs and cats. DESIGN: Retrospective study. ANIMALS: 15 dogs and 3 cats with pleural effusion. PROCEDURE: Medical records were reviewed from 1998 to 2001 for dogs and cats that had exploratory thoracoscopy, biopsy, and histologic analysis to determine the etiology of pleural effusion. Intraoperative and postoperative complications were recorded. Surgical biopsy specimens were evaluated for quantity and quality for providing a histologic diagnosis. RESULTS: Biopsy specimens were deemed adequate in quantity and quality to render a histologic diagnosis in all animals. Etiology of the effusion was neoplasia in 8 animals and non-neoplastic pleuritis in 10 animals. Median survival time of animals with neoplasia was 15 days, whereas those with inflammatory diseases had median survival time of > 785 days. Postoperative pneumothorax was encountered in 2 animals subsequent to pulmonary biopsy. No other major complications were recorded. CONCLUSIONS AND CLINICAL RELEVANCE: Thoracoscopy is a diagnostic option that provides excellent viewing of intrathoracic structures and adequate biopsy specimens with minimal complications. This technique provides a less invasive alternative to thoracotomy for evaluating the etiology of pleural effusion.     

Endoscopic examination of the choanae in dogs and cats: 118 cases (1988-1998).

OBJECTIVE: To determine whether endoscopic examination of the choanae resulted in diagnosis of various diseases in dogs and cats with signs of respiratory tract disease. DESIGN: Retrospective study. ANIMALS: 91 dogs and 27 cats that had endoscopic examination of the choanae. PROCEDURE: Medical records were reviewed for endoscopy findings and results of examination of biopsy or cytologic specimens. RESULTS: 34 animals had neoplasia in the choanal region; in 26 animals, diagnosis was confirmed by evaluation of specimens obtained by endoscopy. Five dogs with neoplasia had an erroneous diagnosis of rhinitis made on the basis of evaluation of specimens obtained by endoscopy. Six dogs and 2 cats had foreign objects in the choanae; 7 foreign objects were removed endoscopically, whereas 1 required nasal flushing. Results of endoscopy and biopsy of the choanae provided diagnosis of cryptococcosis and aspergillosis, but did not aid in the diagnosis of pythiosis or nasal mites. CONCLUSIONS AND CLINICAL RELEVANCE: Endoscopic examination of the choanae may assist in rapid diagnosis of nasal neoplasms, foreign objects, and certain infectious organisms.     

Diagnostic value of cytologic examination of gastrointestinal tract tumors in dogs and cats: 83 cases (2001-2004)

OBJECTIVE: To determine results of cytologic examination of fine-needle aspirates and impression smears of gastrointestinal tract tumors in dogs and cats. DESIGN: Retrospective case series. ANIMALS: 38 dogs and 44 cats with histologically confirmed gastrointestinal tract tumors. PROCEDURES: Results of cytologic examination of fine-needle aspirates (n = 67) or impression smears (31) were compared with the histologic diagnosis, and extent of agreement was classified as complete, partial, none, or undetermined. RESULTS: For 48 of the 67 (72%) fine-needle aspirates, there was complete or partial agreement between the cytologic and histologic diagnoses. For 12 (18%) aspirates, the extent of agreement could not be determined because the cytologic specimen was considered unsatisfactory. For 29 of the 31 (94%) impression smears, there was complete agreement between the cytologic and histologic diagnoses, and for 2 (6%), there was partial agreement. None of the impression smears were considered unsatisfactory. Proportion of samples with complete agreement and proportion of samples with complete or partial agreement were significantly higher for impression smears than for fine-needle aspirates. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that there was moderate agreement between results of cytologic examination of fine-needle aspirates from dogs and cats with gastrointestinal tract neoplasia and the definitive histologic diagnosis. The agreement between results of cytologic examination of impression smears and the histologic diagnosis appeared to be higher.     

Fine-needle aspirate cytology suggesting hepatic lipidosis in four cats with infiltrative hepatic disease

Four cats are reported in which cytology smears obtained by ultrasound-guided fine needle aspiration of the liver were interpreted as indicative of hepatic lipidosis. However, histopathology of hepatic tissue samples obtained with Tru-Cut-like needles or wedge biopsy revealed that the cats had inflammatory or neoplastic hepatic disease causing their clinical signs. Fine needle aspiration and cytology may not detect infiltrative lesions, particularly those that are nodular, multifocal, or localised around the portal regions. Fine needle aspirate cytology is a useful diagnostic procedure with many advantages, but care must be taken to avoid diagnosing hepatic lipidosis as the cause of illness when an infiltrative lesion is responsible.     

Squash-prep cytology in the diagnosis of canine and feline nervous system lesions: a study of 42 cases

BACKGROUND: The increased sophistication of imaging techniques in veterinary medicine allows the detection of a wide variety of intracranial and intraspinal lesions; however, imaging often does not provide a definitive diagnosis for nervous system (NS) lesions. Cytology is emerging as a useful diagnostic tool for obtaining a fast and accurate assessment of NS lesions, but little information is available for dogs and cats. OBJECTIVES: The purpose of this study was to assess the accuracy of cytologic evaluation of squash samples from NS lesions in dogs and cats and to consider cytology-based diagnostic guidelines and sources of misdiagnosis. METHODS: Cytologic specimens from masses localized in the central and peripheral NS taken during surgery or postmortem examination were classified into 3 groups according to the final histopathologic diagnosis: Group 1 = completely correct diagnosis, when the cytologic diagnosis and final histologic diagnosis were exactly correlated; Group 2 = partial correlation, when the cytologic diagnosis only partially correlated with the final histologic diagnosis, and Group 3 = no correlation, when the cytologic diagnosis was incorrect and there was no correlation with the general histologic type of lesion. The diagnostic accuracy of cytopathology was calculated by considering the histopathologic diagnosis as the "gold standard," and calculating a 95% confidence interval (CI). RESULTS: A total of 42 animals (33 dogs and 9 cats) were included in the study. The cytologic diagnoses were classified in Group 1 for 32 cases (76%; 95% CI 0.63-0.89), in Group 2 for 6 cases (14%; 95% CI 0.04-0.25), and in Group 3 for 4 cases (10%; 95% CI 0.006-0.18). Considering both complete and partial correlation as an adequate result, cytologic diagnosis was satisfactory in 90% of biopsies. CONCLUSIONS: Although the current series of cases is relatively small, cytologic evaluation of squash preparations can be considered a fairly accurate and reliable tool in the diagnosis of NS lesions.     

Percutaneous biopsy of abdominal organs under ultrasound guidance

Percutaneous sampling of one or more abdominal organs was performed under ultrasound guidance in 89 dogs and 16 cats. Tissue core samples were considered to be of diagnostic quality in 92 per cent of hepatic and 100 per cent of renal biopsies. Core biopsies were collected from the prostate in only three cases but each was adjudged of diagnostic quality. The technique allowed a definitive diagnosis or normal tissue to be confirmed in 65 per cent of animals undergoing hepatic biopsy, 83 per cent undergoing renal biopsy and 82 per cent undergoing prostatic biopsy or aspiration. Few complications occurred which could be ascribed with certainty to the procedure. One dog with extensive hepatic necrosis died one week after the biopsy, but necropsy examination was denied. One severely debilitated cat did not recover from general anaesthesia. One dog underwent aspiration of a sterile intraprostatic cyst, and developed prostatic abscessation one week later; prostatic carcinoma was subsequently found. Careful selection and preparation of patients for biopsy are essential. With this caveat, ultrasound-guided sampling of abdominal organs is a useful technique allowing a definitive diagnosis in a high proportion of cases. The technique is minimally invasive and the complication rate low.     

Serum lipoprotein concentrations and hepatic lesions in obese cats undergoing weight loss.

Serum lipoprotein concentrations, routine serum biochemical values, and morphologic changes of the liver were evaluated in cats undergoing weight loss. Food was withheld from 6 obese and 6 control cats for 3 days (days 0 to 2), followed by feeding 50% of previous food intake for 26 days (days 3 to 28). Percutaneous liver biopsy specimens were obtained from all cats on days 0, 7, 14, and 28. Blood samples for serum biochemical analysis and lipoprotein profiles were obtained on days 0, 3, 7, 14, and 28. All cats lost weight throughout the study, and none developed signs of clinical illness, including those of idiopathic hepatic lipidosis syndrome. Serum total cholesterol concentrations decreased initially in all cats, but rapidly returned to normal after day 3 in obese cats, suggesting altered cholesterol metabolism during dietary restriction. Low-density lipoprotein concentrations decreased throughout the study in control cats, but were unchanged in obese cats. Examination of liver biopsy specimens from each cat revealed minimal lipid accumulation in all specimens, although some specimens contained hydropic degeneration.     

Erythema multiforme in dogs and cats: literature review and case material from the Cornell University College of Veterinary Medicine (1988–96)

A review of case material from the Cornell University College of Veterinary Medicine from 1988 to 1996 identified 20 dogs and one cat with definitive or presumed erythema multiforme. An additional 24 dogs and five cats with definitive or presumed erythema multiforme were found in the veterinary literature. Erythema multiforme accounted for only 0.40% and 0.11%, respectively, of all the canine and feline dermatology cases examined over a 9-year period. German Shepherd dogs and Pembroke Welsh Corgis appeared predisposed. The condition was manifested as a vesiculobullous and/or ulcerative dermatosis in the majority of dogs and cats. In dogs, the most commonly affected body sites included the ventrum (especially axillae and groin), mucocutaneous junctions, oral cavity, pinnae, and footpads. Histopathological findings in cutaneous and mucocutaneous biopsy specimens were consistent with previously published criteria. In dogs, erythema multiforme occurred more frequently in patients receiving drug therapy. In cats, all cases of erythema multiforme were presumed to be drug related. Elimination of the associated trigger factor and supportive care usually resulted in resolution of the erythema multiforme within 1–2 weeks. Four dogs with severe idiopathic erythema multiforme were successfully managed with glucocorticoids or azathioprine.     

Liver cytology.

Physical examination, clinical laboratory testing, and medical imaging are effective in establishing the presence of liver disease; however, they infrequently establish a definitive diagnosis. Morphologic evaluation of liver tissue is generally accepted as a valuable diagnostic tool in establishing a diagnosis in liver disease. Clinicians have several options for obtaining specimens for morphologic evaluation, including surgically obtained wedge biopsies, percutaneous core biopsies, and fine-needle aspiration specimens. Surgical and core biopsy procedures require anesthesia or sedation and have a substantial risk of bleeding complications. Fine-needle aspiration usually does not require sedation and is rarely associated with hemorrhage; thus, it is frequently chosen for animals that are poor anesthetic risks or have coagulopathies. Diseases like malignant lymphoma, hepatic lipidosis, and suppurative hepatitis are readily diagnosed cytologically, whereas hepatocellular adenomas, hyperplastic nodules, fibrosis, and chronic inflammation are more difficult to identify cytologically.     

SAFETY AND CORRELATION OF TEST RESULTS OF COMBINED ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION AND NEEDLE CORE BIOPSY OF THE CANINE SPLEEN

The safety and diagnostic value of combined splenic fine‐needle aspiration (FNA) and needle core biopsy (NCB) is unknown. Forty‐one dogs with splenic lesions were studied prospectively. Safety was assessed in 38 dogs and no complications were encountered. Initially, clinical and anatomic pathologists reviewed each FNA and NCB sample, respectively, without knowledge of the other's results. Diagnoses were categorized as neoplastic, benign, inflammatory, normal, or nondiagnostic. The level of agreement between sampling methods was categorized as complete, partial, disagreement, or not available. Test correlation was performed in 40 dogs. Nondiagnostic results occurred in 5/40 NCB (12.5%) and no FNA samples. Neoplasia was diagnosed in 17/40 dogs (42.5%), benign changes in 20/40 dogs (50%), inflammatory disorders in 0/40 dogs, and normal 2/40 dogs (5%). One of the 40 dogs (2.5%) had a diagnosis that was equivocal for neoplasia on both tests and therefore was not categorized. Of the 35 dogs that had diagnostic samples, cytopathologic and histopathologic diagnoses agreed completely in 18/35 dogs (51.4%), partially in 3/35 dogs (8.6%), and were in disagreement in 14/35 dogs (40.0%). Pathologists collaboratively reviewed diagnoses that were in disagreement or partial agreement and altered their individual diagnoses in 6/17 dogs (35.3%) to be within partial or complete agreement, respectively. Percutaneous FNA and NCB can be performed safely in dogs with sonographic splenic changes. Results suggest that adding NCB to FNA provides complementary information in dogs with suspected splenic neoplasia. This combined protocol may improve detection of splenic neoplasia and provide neoplastic subclassification.