Feline gastrointestinal lymphoma

[Cytologic evidence of hepatocytotropic T-cell-lymphoma in a 15-year-old male cat]

This case report describes the rare phenomenon of emperipolesis-like invasion of lymphatic blasts into the hepatocytes of a 15-year-old European Shorthair cat. The cat presented with nonspecific clinical signs (inappetence and weight loss). Cytologic examination of an ultrasound-guided fine-needle aspirate of the liver showed a subset of hepatocytes with emperipolesis-like invasion by lymphatic blasts. Few extracellularly located lymphatic blasts exhibited erythrophagia. Following the cytological diagnosis of large cell lymphoma and 2 weeks of monotherapy with prednisolone, the patient was euthanized due to his poor general condition. A post-mortem sample was obtained from the liver to confirm the suspected cytological diagnosis of hepatocytotropic lymphoma. Histopathology subsequently confirmed the cytologic findings. Immunohistochemically, the lymphatic blasts were positive for CD3 leading to a diagnosis of hepatocytotropic T-cell-lymphoma, which has rarely been described so far.

Fecal acute phase proteins in cats with chronic enteropathies

BACKGROUND

Chronic enteropathies (CE) are common in cats and reliable biomarkers that can distinguish different causes and predict or monitor response to treatment are currently lacking.

HYPOTHESIS

To evaluate certain acute phase proteins in feces that could potentially be used as biomarkers in cats with CE.

ANIMALS

Twenty-eight cats with either inflammatory bowel disease (IBD; n = 13), food-responsive enteropathy (FRE; n = 3) or small cell gastrointestinal lymphoma (SCGL; n = 12) and 29 healthy control cats were prospectively enrolled.

METHODS

Fecal concentrations of haptoglobin, alpha-1-acid-glycoprotein (AGP), pancreatitis-associated protein-1 (PAP-1), ceruloplasmin, and C-reactive protein (CRP) were measured using Spatial Proximity Analyte Reagent Capture Luminescence (SPARCL) immunoassays before and after initiation of treatment. Cats were treated with diet and/or prednisolone (IBD cats), plus chlorambucil (SCGL cats).

RESULTS

Compared with controls, median fecal AGP concentrations were significantly lower (25.1 vs 1.8 μg/g; P = .003) and median fecal haptoglobin (0.17 vs 0.5 μg/g), PAP-1 (0.04 vs 0.4 μg/g) and ceruloplasmin (0.15 vs 4.2 μg/g) concentrations were significantly higher (P < .001) in cats with CE. Median fecal AGP concentrations were significantly lower (P = .01) in cats with IBD and FRE (0.6 μg/g) compared with cats with SCGL (10.75 μg/g). A significant reduction was found in CE cats after treatment for median fecal ceruloplasmin concentrations (6.36 vs 1.16 μg/g; P = .04).

CONCLUSIONS

Fecal AGP concentration shows promise to differentiate cats with SCGL from cats with IBD and FRE. Fecal ceruloplasmin concentrations may be useful to objectively monitor response to treatment in cats with CE.

Fecal Calprotectin Concentrations in Cats with Chronic Enteropathies

Diagnosis of feline chronic inflammatory enteropathies (CIE) and the differentiation from small cell intestinal lymphoma (SCL) can be challenging. Intestinally expressed calprotectin (S100A8/A9 protein complex) appears to be part of the complex pathogenesis of feline chronic enteropathies (FCE). Fecal calprotectin is a non-invasive biomarker for intestinal inflammation in humans and dogs but has not yet been evaluated in cats. We hypothesized that fecal calprotectin (fCal) concentrations are increased in FCE, correlate with clinical and/or histologic disease severity, and distinguish cases of CIE from SCL. This case-control study included fecal samples and patient data from cats with CIE (n = 34), SCL (n = 17), other gastrointestinal (GI) diseases (n = 16), and cats with no clinical signs of GI disease (n = 32). fCal concentrations were measured using the immunoturbidimetric fCal turbo assay (Bühlmann Laboratories). Compared to healthy cats, fCal concentrations were significantly increased in CIE, SCL, and other diseases (all p < 0.0001), but were not different between these three groups (all p > 0.05), or between cats with extra-GI diseases and healthy controls. These findings suggest that fCal may have utility as a clinical biomarker for FCE but not for intestinal disease differentiation. It further supports the role of calprotectin in the pathogenesis of the spectrum of FCE, which includes CIE and SCL.

B-mode ultrasound and colour Doppler findings in cats with gastric lymphoma

OBJECTIVES

The purpose of this study was to describe B-mode and colour Doppler ultrasound (US) features of gastric lymphoma in cats.

METHODS

Cats with histopathological or cytological confirmation of gastric lymphoma that underwent abdominal US were included in this retrospective study. Clinical signs were recorded and radiographs reviewed when available. Gastric lesions were ultrasonographically evaluated for location, distribution, wall layering, echogenicity and thickness. Colour Doppler assessment was based on vessels, location and direction.

RESULTS

Forty-five cats were included. All presented with vomiting, 7/45 (15.5%) with haematemesis. Radiographs were available in 27/45 cases, and demonstrated a gastric mass in 19/27 (70.4%) cases. The most common US appearance was transmural wall thickening with absent layering 42/45 (93.3%) and hypoechogenicity 39/45 (86.7%). Median maximum thickness was 2.1 cm. Ulceration or erosion was suspected in 23/45 (51%) cases, two of which perforated. Colour Doppler images were available in 33/45 cases. The most common Doppler finding was transmural vessels coursing perpendicularly to the lumen in 14/33 (42.4%). Abdominal effusion was uncommon (n = 11/45; 24.4%). Regional lymphadenopathy was frequent, observed in 44/54 lymph nodes reviewed on US, and US suspicion of splenic, hepatic and intestinal lymphomatous infiltration was reported in 24/45 (53.3%) cases.

CONCLUSIONS AND RELEVANCE

The most common US appearance of gastric lymphoma was transmural hypoechoic segmental wall thickening with layering loss. Location and distribution were variable. Colour Doppler displayed increased blood supply with a predominant pattern of perpendicular vessels, possibly representing aberrant arteries originating from subserosal and submucosal plexus. Lymphomatous infiltration of lymph nodes and other abdominal organs was frequent, confirming local and distant aggressiveness of gastric lymphoma in cats. Vomiting and haematemesis were frequently associated with the suspicion of ulcer on US. Perforation was a rare occurrence.

Utility of fluorescence imitating brightfield imaging microscopy for the diagnosis of feline chronic enteropathy

Fluorescence imitating brightfield imaging (FIBI) is a novel microscopy method that allows for real-time, nondestructive, slide-free tissue imaging of fresh, formalin-fixed, or paraffin-embedded tissue. The nondestructive nature of the technology permits tissue preservation for downstream analyses. The objective of this observational study was to assess the utility of FIBI compared with conventional hematoxylin and eosin (H&E)-stained histology slides in feline gastrointestinal histopathology. Formalin-fixed paraffin-embedded full-thickness small intestinal tissue specimens from 50 cases of feline chronic enteropathy were evaluated. The ability of FIBI to evaluate predetermined morphological features (epithelium, villi, crypts, lacteals, fibrosis, submucosa, and muscularis propria) and inflammatory cells was assessed on a 3-point scale (0 = FIBI cannot identify the feature; 1 = FIBI can identify the feature; 2 = FIBI can identify the feature with more certainty than H&E). H&E and FIBI images were also scored according to World Small Animal Veterinary Association (WSAVA) Gastrointestinal Standardization Group guidelines. FIBI identified morphological features with similar or, in some cases, higher confidence compared with H&E images. The identification of inflammatory cells was less consistent. FIBI and H&E images showed an overall poor agreement with regard to the assigned WSAVA scores. While FIBI showed an equal or better ability to identify morphological features in intestinal biopsies, its ability to identify inflammatory cells is currently inferior compared with H&E-based imaging. Future studies on the utility of FIBI as a diagnostic tool for noninflammatory histopathologic lesions are warranted.

Relationship between Serum Protein Electrophoresis, Endoscopic and Histopathological Scores in 99 Cats with Chronic Enteropathy

Simple Summary

Serum protein electrophoresis (SPE) is a laboratory test used to separate different protein fractions. It is used to investigate animals with hyperglobulinemia and to distinguish between monoclonal and polyclonal gammopathies. SPE can also highlight acute or chronic inflammation patterns which are useful in disease monitoring. SPE is effective in humans with intestinal bowel disease (IBD) and chronic liver diseases. In addition, hypergammaglobulinemia is a marker of extraintestinal manifestations in human IBD patients, which often includes hepatic and pancreatic disease. Concurrent pancreatic and/or hepatic diseases in cats with chronic enteropathy (CE) have often been found, which may contribute to SPE alterations. The present study investigated the relationship between SPE and endoscopy, histopathology, and hepatic and pancreatic ultrasonographic findings in ninety-nine cats diagnosed with CE. No significant differences were observed between SPE and endoscopic and histopathological severity scores. Cats with concurrent pancreatic and/or hepatic ultrasonographic alterations showed lower albumin, lower α-globulin, and higher γ-globulin levels than cats diagnosed with enteropathy alone. This study suggests that hepatic and/or pancreatic alterations may influence SPE fractions in cats with CE, and should form the basis for further prospective studies on cats with diaditis and triaditis.

Abstract

Few studies have investigated total protein (TP) and serum protein electrophoresis (SPE) in cats with chronic enteropathy (CE). Cats diagnosed with CE were evaluated to investigate the relationships between TP, SPE and endoscopy, histopathology, and extraintestinal involvement. Medical records were searched for cats with a history of chronic gastrointestinal signs and a final diagnosis of CE. Information on signalment, TP, SPE, endoscopic score, histopathological diagnosis and score, and concurrent hepatic or pancreatic ultrasonographic alterations was collected. Relationships between protein profiles and other variables were investigated. Ninety-nine cats were included in the study, 63 diagnosed with various degrees of bowel inflammation and 36 with small-cell alimentary lymphoma. The most common TP alteration was hypoproteinemia (24%). No significant differences were observed between protein profiles and endoscopic and histopathological severity scores. Forty-five cats showing concurrent pancreatic and/or hepatic ultrasonographic alterations, had significantly lower albumin, lower α-globulin, and higher γ-globulin levels than cats not showing concurrent alterations. Disease severity scores did not seem to influence the protein profile in cats with CE. Extraintestinal involvement may be suspected in cats with lower albumin and α-globulins and higher γ-globulins.

Intestinal S100/Calgranulin Expression in Cats with Chronic Inflammatory Enteropathy and Intestinal Lymphoma

Simple Summary

Intestinal diseases in cats are complicated diseases in which intestinal inflammation is difficult to distinguish from lymphoma, which is a neoplasm. In this study, the expression of the proteins S100A8/A9 and S100A12 (also called calgranulins) in the intestine is investigated in both diseases and for potential correlations with microscopically visible changes in the intestine or the clinical severity of the disease. Only small differences were seen between healthy and diseased animals, and there were no differences between cats with intestinal inflammation and lymphoma. However, several correlations of cells staining positive for calgranulins and inflammatory changes at the microscopic level and clinical disease severity were shown. This indicates that calgranulins play a role in both gastrointestinal lymphoma and inflammation and would support the recent theory that these two diseases might not be separate disease entities but instead are related. Further insights into the role of the calgranulins in these feline diseases will lead to a better understanding of the disease pathogenesis and, thus, potentially novel diagnostics and treatment avenues.

Abstract

Diagnosing chronic inflammatory enteropathies (CIE) in cats and differentiation from intestinal lymphoma (IL) using currently available diagnostics is challenging. Intestinally expressed S100/calgranulins, measured in fecal samples, appear to be useful non-invasive biomarkers for canine CIE but have not been evaluated in cats. We hypothesized S100/calgranulins to play a role in the pathogenesis of feline chronic enteropathies (FCE) and to correlate with clinical and/or histologic disease severity. This retrospective case-control study included patient data and gastrointestinal (GI) tissues from 16 cats with CIE, 8 cats with IL, and 16 controls with no clinical signs of GI disease. GI tissue biopsies were immunohistochemically stained using polyclonal α-S100A8/A9 and α-S100A12 antibodies. S100A8/A9⁺ and S100A12⁺ cells were detected in all GI segments, with few significant differences between CIE, IL, and controls and no difference between diseased groups. Segmental inflammatory lesions were moderately to strongly correlated with increased S100/calgranulin-positive cell counts. Clinical disease severity correlated with S100A12⁺ cell counts in cats with IL (ρ = 0.69, p = 0.042) and more severe diarrhea with colonic lamina propria S100A12⁺ cells with CIE (ρ = 0.78, p = 0.021) and duodenal S100A8/A9⁺ cells with IL (ρ = 0.71, p = 0.032). These findings suggest a role of the S100/calgranulins in the pathogenesis of the spectrum of FCE, including CIE and IL.

Pathohistological features of mediastinal lymphoma in domestic cats

The article covers two clinical cases of domestic cats suffering from a mediastinal form of lymphoma and provides their cytological, immunohistochemical, and pathohistological verification. The lymphoma immunophenotyping method using the B-cell markers CD79a and CD3 was used to identify T-cells. The mediastinal type of lymphoma in cats is usually rarely registered and statistically, the number of cases does not exceed 20%, which is consistent with our observations. Shortness of breath, difficulty with swallowing, lack of appetite, cyanotic mucous membranes, lymphadenomegaly of the mediastinal lymph nodes and effusion in the chest cavity were found in the clinically ill cats. An X-ray examination of the chest cavity revealed an increased contrast in the mediastinal area and displacement of the lungs towards the spine. A complete blood count revealed lymphopenia. Cytological smears of the chest cavity transudates revealed mostly monomorphic lymphoblasts with large rounded hyperchromic nuclei and narrow cytoplasm stained in light blue. The karyoplasm was somewhat granular, the nucleoli were visible, and the mitoses were atypical and numerous. The cytological picture in biopsy samples of mediastinal lymph nodes was characterized by a monomorphic population of lymphoblasts with an eccentrically located nucleus and moderately basophilic karyoplasm. The cell cytoplasm was vacuolated in some places, with presence of atypical mitotic figures. Most of the cells had two nuclei. Diffuse tumoral lesions of the chest cavity tissues, focal tumorous lesions of the lung parenchyma, and lymphadenopathy of the mediastinal lymph nodes were found during the autopsy in the first case. The second clinical case demonstrated the massive lymphadenopathy of the mediastinal lymph nodes. Histologically, a diffuse lesion by a monomorphic population of lymphoblasts was revealed in preparations from the soft tissues of the chest wall. The lymphoblasts’ insignificant cytoplasm, with nuclei from round to elliptical shape, infiltrated the chest wall’s soft tissues. It was found immunohistochemically that the blast cells showed reactivity to CD79a, and were mostly negative to CD3. This indicates the development of a large diffuse B-cell lymphoma. The immunohistochemical picture of lymph node necropsies from another cat was somewhat similar. However, it was also characterized by lymphoblasts with eccentrically placed nuclei, increased number of cells with mitotic figures, somewhat intensive CD3 antibodies expression (especially in the paracortical area of lymph nodes), and significant CD79a marker expression.

Clinical, laboratory and ultrasonographic findings differentiating low-grade intestinal T-cell lymphoma from lymphoplasmacytic enteritis in cats

Background

Low‐grade intestinal T‐cell lymphoma (LGITL) is the most common intestinal neoplasm in cats. Differentiating LGITL from lymphoplasmacytic enteritis (LPE) is challenging because clinical signs, laboratory results, diagnostic imaging findings, histology, immunohistochemistry, and clonality features may overlap.

Objectives

To evaluate possible discriminatory clinical, laboratory and ultrasonographic features to differentiate LGITL from LPE.

Animals

Twenty‐two cats diagnosed with LGITL and 22 cats with LPE based upon histology, immunohistochemistry, and lymphoid clonality.

Methods

Prospective, cohort study. Cats presented with clinical signs consistent with LGITL or LPE were enrolled prospectively. All data contributing to the diagnostic evaluation was recorded.

Results

A 3‐variable model (P < .001) consisting of male sex (P = .01), duration of clinical signs (P = .01), and polyphagia (P = .03) and a 2‐variable model (P < .001) including a rounded jejunal lymph node (P < .001) and ultrasonographic abdominal effusion (P = .04) were both helpful to differentiate LGITL from LPE.

Conclusions and Clinical Importance

Most clinical signs and laboratory results are similar between cats diagnosed with LGITL and LPE. However, male sex, a longer duration of clinical signs and polyphagia might help clinicians distinguish LGITL from LPE. On ultrasonography, a rounded jejunal lymph node, and the presence of (albeit small volume) abdominal effusion tended to be more prevalent in cats with LGITL. However, a definitive diagnosis requires comprehensive histopathologic and phenotypic assessment.

Differentiating Inflammatory Bowel Disease from Alimentary Lymphoma in Cats: Does It Matter?

Differentiation of feline inflammatory bowel disease and intestinal small cell lymphoma can be challenging, and some clinicians argue that it is unnecessary because prognosis and treatment are similar. Differentiation of feline inflammatory bowel disease and intestinal small cell lymphoma can be challenging and some clinicians argue that it is unnecessary since prognosis and treatment are similar. Altough the body of research on this topic has increased over time, we still know little about etiopathogenesis, progression, alternative treatment modalities and prognosis of the different forms of FCE. While differentiating IBD from SCL might not alter a single patients' disease course, further research efforts are required to alter the disease course for our feline patient population as a whole.

Feline chronic enteropathy

Feline chronic enteropathy is a common disorder, especially in the senior cat population, with rising incidence over the past decade. Feline chronic enteropathy is considered an umbrella term comprising different diseases including food-responsive enteropathy, idiopathic inflammatory bowel disease and alimentary small cell lymphoma. However, differentiation between those diseases is often difficult in practice. This review will discuss the clinical approach to cats with chronic enteropathy, state-of-the-art diagnostic tests and pitfalls thereof as well as current therapeutic approaches. Although, much of the etiopathogenesis is still unknown, increased research efforts in this field have brought new insights into diagnostic and therapeutic options for these cats.

Intestinal T-cell lymphoma in a coati (Nasua nasua) - Short communication

A 10-year-old female coati (Nasua nasua) was necropsied after an 8-day history of apathy, weight loss and dehydration. Gross changes consisted of multifocal to coalescing nodules ranging from 0.5 to 2.0 cm in diameter in the wall of the small intestine, adjacent to the mesentery and in the mesenteric lymph nodes. Histologically, neoplastic CD3-positive lymphocytes infiltrated all layers of the intestine, as well as the mesenteric adipose tissue and mesenteric lymph nodes. Based on the pathological and immunohistochemical findings, a diagnosis of intestinal T-cell lymphoma was made.

Triaditis: Truth and Consequences

Clinical findings with triaditis and individual disease components overlap and may include hyporexia, weight loss, lethargy, vomiting, diarrhea, dehydration, icterus, abdominal pain, thickened bowel loops, pyrexia, dyspnea, and shock. A definitive diagnosis of triaditis requires histologic confirmation of inflammation in each organ, but this may not be possible because of financial or patient-related constraints. Evidence-based data indicate that histologic lesions of triaditis are present in 30% to 50% of cats diagnosed with pancreatitis and cholangitis/inflammatory liver disease. Treatment of triaditis is based on the overall health status of the patient and the type and severity of disease in component organs.

Differentiation of lymphocytic-plasmacytic enteropathy and small cell lymphoma in cats using histology-guided mass spectrometry

BACKGROUND

Differentiation of lymphocytic-plasmacytic enteropathy (LPE) from small cell lymphoma (SCL) in cats can be challenging.

HYPOTHESIS/OBJECTIVE

Histology-guided mass spectrometry (HGMS) is a suitable method for the differentiation of LPE from SCL in cats.

ANIMALS

Forty-one cats with LPE and 52 cats with SCL.

METHODS

This is a retrospective clinicopathologic study. Duodenal tissue samples of 17 cats with LPE and 22 cats with SCL were subjected to HGMS, and the acquired data were used to develop a linear discriminate analysis (LDA) machine learning algorithm. The algorithm was subsequently validated using a separate set of 24 cats with LPE and 30 cats with SCL. Cases were classified as LPE or SCL based on a consensus by an expert panel consisting of 5-7 board-certified veterinary specialists. Histopathology, immunohistochemistry, and clonality testing were available for all cats. The panel consensus classification served as a reference for the calculation of test performance parameters.

RESULTS

Relative sensitivity, specificity, and accuracy of HGMS were 86.7% (95% confidence interval [CI]: 74.5%-98.8%), 91.7% (95% CI: 80.6%-100%), and 88.9% (95% CI: 80.5%-97.3%), respectively. Comparatively, the clonality testing had a sensitivity, specificity, and accuracy of 85.7% (95% CI: 72.8%-98.7%), 33.3% (95% CI: 14.5%-52.2%), and 61.5% (95% CI: 48.3%-74.8%) relative to the panel decision.

CONCLUSIONS AND CLINICAL IMPORTANCE

Histology-guided mass spectrometry was a reliable technique for the differentiation of LPE from SCL in duodenal formalin-fixed paraffin-embedded samples of cats and might have advantages over tests currently considered state of the art.

Feline low-grade alimentary lymphoma: an emerging entity and a potential animal model for human disease

BACKGROUND

Low-grade alimentary lymphoma (LGAL) is characterised by the infiltration of neoplastic T-lymphocytes, typically in the small intestine. The incidence of LGAL has increased over the last ten years and it is now the most frequent digestive neoplasia in cats and comprises 60 to 75% of gastrointestinal lymphoma cases. Given that LGAL shares common clinical, paraclinical and ultrasonographic features with inflammatory bowel diseases, establishing a diagnosis is challenging. A review was designed to summarise current knowledge of the pathogenesis, diagnosis, prognosis and treatment of feline LGAL. Electronic searches of PubMed and Science Direct were carried out without date or language restrictions.

RESULTS

A total of 176 peer-reviewed documents were identified and most of which were published in the last twenty years. 130 studies were found from the veterinary literature and 46 from the human medicine literature. Heterogeneity of study designs and outcome measures made meta-analysis inappropriate. The pathophysiology of feline LGAL still needs to be elucidated, not least the putative roles of infectious agents, environmental factors as well as genetic events. The most common therapeutic strategy is combination treatment with prednisolone and chlorambucil, and prolonged remission can often be achieved. Developments in immunohistochemical analysis and clonality testing have improved the confidence of clinicians in obtaining a correct diagnosis between LGAL and IBD. The condition shares similarities with some diseases in humans, especially human indolent T-cell lymphoproliferative disorder of the gastrointestinal tract.

CONCLUSIONS

The pathophysiology of feline LGAL still needs to be elucidated and prospective studies as well as standardisation of therapeutic strategies are needed. A combination of conventional histopathology and immunohistochemistry remains the current gold-standard test, but clinicians should be cautious about reclassifying cats previously diagnosed with IBD to lymphoma on the basis of clonality testing. Importantly, feline LGAL could be considered to be a potential animal model for indolent digestive T-cell lymphoproliferative disorder, a rare condition in human medicine.

Pilot study: duodenal MDR1 and COX2 gene expression in cats with inflammatory bowel disease and low-grade alimentary lymphoma

Objectives Multidrug resistance 1 (MDR1) encodes a protein called P-glycoprotein (P-gp), which serves as an efflux pump membrane protein implicated in intestinal homeostasis and drug resistance. Cyclooxygenase-2 (COX2) is a key enzyme in the synthesis of proinflammatory prostaglandins, tumourigenesis and in mucosal defence. Despite the importance of MDR1 and COX2, changes in their mRNA levels have not been studied in cats with inflammatory bowel disease (IBD) and low-grade alimentary lymphoma (LGAL). The present study aimed to determine the mRNA levels of MDR1 and COX2 in cats with IBD and LGAL, and to evaluate their correlation with clinical signs, histological severity and between genes. Methods Cats diagnosed with IBD (n = 20) and LGAL (n = 9) between 2008 and 2015 were included in the current study. Three healthy animals composed the healthy control cats group in which endoscopy was performed immediately before the ovariohysterectomy. All duodenal biopsy samples were obtained by endoscopy. Feline chronic enteropathy activity index was calculated for all cases. IBD histopathology was classified according to severity. MDR1 and COX2 mRNA levels were determined by absolute reverse transcriptase-quantitative real-time PCR. Results Statistically significant differences were observed for MDR1 and COX2 mRNA levels between the IBD and LGAL groups. No correlations were observed between molecular gene expression, feline chronic enteropathy activity index and histological grading for IBD, and between MDR1 and COX2 genes. However, a positive statistically significant correlation was observed between MDR1 and COX2 expression in the duodenum of cats. Conclusions and relevance MDR1 and COX2 gene expression is increased in cats with LGAL compared with cats with IBD. The control group tended to have lower values than both diseased groups. These results suggest that these genes may be involved in the pathogenesis of IBD or LGAL in cats.

Post-chemotherapy perforation in cats with discrete intermediate- or large-cell gastrointestinal lymphoma

Objectives Gastrointestinal (GI) perforation is a well described complication of GI lymphoma in people, commonly occurring within days of initiation of chemotherapy. There are no studies documenting the prevalence of GI perforation in cats with intermediate- or large-cell GI lymphoma or whether it is associated with induction of chemotherapy. The objectives of this study were to document the prevalence and timing of post-chemotherapy perforation in cats with discrete GI masses caused by intermediate- or large-cell lymphoma. Methods Cats with a diagnosis of intermediate- or large-cell lymphoma based on cytologic or histopathologic examination of a mass lesion of the GI tract and treated with chemotherapy were identified by searching the patient record database of three large specialty referral hospitals. Cats undergoing surgical resection of a GI mass prior to chemotherapy were excluded from the study. A clinical diagnosis of GI perforation was made using ultrasound findings and analysis of abdominal fluid. Results Twenty-three cats with intermediate- (n = 3) or large-cell (n = 20) lymphoma were included in the study. GI perforation was confirmed in 4/23 cats (17%), and occurred at 23, 56, 59 and 87 days after induction. There was no association between tumor size, the presence of hypoproteinemia or suppurative inflammation within the mass at the time of diagnosis and subsequent perforation. Post-hoc analysis revealed that the magnitude of weight loss within 15-28 days of diagnosis was greater in cats with perforation. Conclusions and relevance In this pilot study, we found that post-chemotherapy GI perforation in cats with intermediate- or large-cell GI lymphoma occurs. Acute perforation after induction of chemotherapy was not documented. Larger prospective studies are needed to determine risk factors associated with perforation and whether surgical excision would reduce the risk of subsequent GI perforation in these patients.

Flow cytometry for feline lymphoma: a retrospective study regarding pre-analytical factors possibly affecting the quality of samples

Objectives Flow cytometry (FC) is becoming increasingly popular among veterinary oncologists for the diagnosis of lymphoma or leukaemia. It is accurate, fast and minimally invasive. Several studies of FC have been carried out in canine oncology and applied with great results, whereas there is limited knowledge and use of this technique in feline patients. This is mainly owing to the high prevalence of intra-abdominal lymphomas in this species and the difficulty associated with the diagnostic procedures needed to collect the sample. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis. Methods Ninety-seven consecutive samples of suspected feline lymphoma were retrospectively selected from the authors' institution's FC database. The referring veterinarians were contacted and interviewed about several different variables, including signalment, appearance of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of it being finally processed for FC. Results Sample cellularity is a major factor in the likelihood of the sample being processed. Moreover, sample cellularity was significantly influenced by the needle size, with 21 G needles providing the highest cellularity. Notably, the sample cellularity and the likelihood of being processed did not vary between peripheral and intra-abdominal lesions. Approximately half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling). Conclusions and relevance FC can be safely applied to cases of suspected feline lymphomas, including intra-abdominal lesions. A 21 G needle should be preferred for sampling. This study provides the basis for the increased use of this minimally invasive, fast and cost-effective technique in feline medicine.

Cyclooxygenase-2 immunoexpression in intestinal epithelium and lamina propria of cats with inflammatory bowel disease and low grade alimentary lymphoma

Background

Cyclooxygenase 2 (COX-2) is an inducible isoform by cellular activation, proinflammatory cytokines and growth factors. The aims of the current study were to evaluate COX-2 immunoexpression in epithelial and lamina propria (LP) of cats with inflammatory bowel disease (IBD) and low grade alimentary lymphoma (LGAL), as well as to correlate them with clinical signs and histopathological scoring. Cats diagnosed with IBD and LGAL (2007–2013) were included in the current study. Feline chronic enteropathy activity index (FCEAI) was calculated for all cases. Control group was composed by 3 healthy indoor cats and 5 sick cats died or were euthanized (non-gastrointestinal illness). Diagnosis and classification of IBD and LGAL was established according to the WSAVA gastrointestinal standardization group template and the National Cancer Institute formulation, respectively. Furthermore, a modified WSAVA template was applied for LGAL evaluation. Immunolabelling for COX-2 (polyclonal rabbit anti-murine antibody) was performed on biopsy samples. Epithelial and LP (inflammatory or neoplastic cells) COX-2 immunolabelling was calculated according to the grade and intensity. The most representative segment scored by the WSAVA and the modified WSAVA were used for statistical analysis.

Results

Significant difference was found regarding COX-2 intensity overexpression in the epithelial cells of IBD and LGAL groups when compared to control cats, but not between the groups of sick cats, whereas no differences were found regarding the grade of immunoreactivity between groups. No difference was found for COX-2 immunoexpression at the LP between all groups. However, 3 cats from LGAL group showed COX-2 expression in neoplastic cells at the LP. There were no correlations between epithelial or LP COX-2 expression and FCEAI and histological alterations.

Conclusions

Increased COX-2 intensity at the epithelial cells observed in cats with IBD and LGAL may be secondary to the inflammatory response or a protective function in the intestinal reparation. COX-2 expression at the LP was presented in 33% of LGAL. This result provides a reason for further investigation concerning the role of COX-2 expression in feline alimentary lymphoma.

Identification of Mucosa-Invading and Intravascular Bacteria in Feline Small Intestinal Lymphoma

Persistent bacterial infections of the gastrointestinal mucosa are causally linked to gastric carcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma in people and laboratory animals. We examined the relationship of mucosa-associated bacteria to alimentary lymphoma in cats. Intestinal biopsies from 50 cats with alimentary lymphoma (small cell, n = 33; large cell, n = 17) and 38 controls without lymphoma (normal to minimal change on histopathology, n = 18; lymphocytic-plasmacytic enteritis, n = 20) were evaluated. The number and spatial distribution of bacteria (ie, in luminal cellular debris, villus-associated mucus, adherent to epithelium, mucosal invasion, intravascular, or serosal) were determined by fluorescence in situ hybridization with the eubacterial probe EUB-338. Mucosa-invasive bacteria were more frequently observed in cats with large cell lymphoma (82%, P ≤ .001) than in cats with small cell lymphoma (18%), normal to minimal change on histopathology, and lymphocytic-plasmacytic enteritis (3%). Intravascular bacteria were observed solely in large cell lymphoma (29%), and serosal colonization was more common in cats with large cell lymphoma (57%) than with small cell lymphoma (11%, P ≤ .01), normal to minimal change (8%, P ≤ .01), and lymphocytic-plasmacytic enteritis (6%, P ≤ .001). The high frequency of invasive bacteria within blood vessels and serosa of cats with large cell lymphoma may account for the sepsis-related complications associated with large cell lymphoma and inform clinical management. Further studies are required to determine the role of intramucosal bacteria in the etiopathogenesis of feline alimentary lymphoma.

Evaluation of Pax5 expression and comparison with BLA.36 and CD79αcy in feline non-Hodgkin lymphoma

Paired box gene 5 (Pax5) is a widely used B-cell marker for human and canine non-Hodgkin's lymphoma (nHL); however, in the literature there is only one case report using Pax5 in a cat B-cell lymphoma. The purposes of this study were to investigate the expression and detection of B-cell specific activator protein (BSAP) using a monoclonal anti-Pax5 antibody in feline nHL (FnHL) tissue samples to evaluate its diagnostic relevance as a B-cell marker. A total of 45 FnHL samples in 45 cats were evaluated. B-cell lymphoma was the most common immunophenotype (51.1%) for all the samples and T-cell the most common immunophenotype (64.3%) for the gastrointestinal (GI) form. Pax5 stained 82.6% of all B-cell lymphomas and no expression was found in any of the T-cell lymphomas. Anti-Pax5 antibody staining in FnHL is similar to that reported in human and canine counterparts and may offer an excellent B-cell marker in cats.

Diagnostic exercise: Submucosal gastric masses in a cat

A 14-year-old neutered male cat presenting with chronic vomiting had 2 masses within the submucosa of the stomach that were excised. They presented histologically as circumscribed, submucosal masses consisting of diffusely arranged medium-sized round cells with a moderate amount of cytoplasm and interspersed eosinophils, separated by trabecular fibroblastic stroma. The overlying mucosa was diffusely infiltrated by the same round cells, and marked epitheliotropism was present. Neoplastic cells labelled positive for CD3 and negative for CD79a and CD117. Giemsa staining and silver staining (SNOBA) were also negative. A T-cell lymphoma with reactive fibroplasia was diagnosed, and differential diagnoses including mast cell tumor and feline gastrointestinal eosinophilic sclerosing fibroplasia could be excluded.

Changes in prevalence of progressive feline leukaemia virus infection in cats with lymphoma in Germany

Progressive infection with feline leukaemia virus (FeLV) is considered one of the major risk factors for development of feline lymphoma. The aim of this study was to compare cats with lymphoma between 1980 and 1994 (first period) and between 1995 and 2009 (second period) concerning FeLV antigenaemia and age distribution. In addition, differences between FeLV antigen-positive and antigen-negative cats with lymphoma regarding patients' characteristics, tumour location and outcome were evaluated. There was a significant decrease in the percentage of lymphoma cases associated with progressive FeLV infection from the first (59 per cent) to the second (13 per cent) observation period. FeLV antigen-positive cats were significantly younger (median 3.7 v 11.3 years), and had significantly shorter response duration (median 25 days v 472 days) with therapy. In the cats of the second period, gastrointestinal and extranodal lymphomas were the most common anatomical sites, and the majority of those cats were FeLV antigen-negative. Thus, other aetiologies than progressive FeLV infection must have a greater impact on cancerogenesis among affected cats with lymphoma to date.

Expression of the Bcl-2 apoptotic marker in cats diagnosed with inflammatory bowel disease and gastrointestinal lymphoma

Immunolabeling for the critical lymphocyte survival factor, Bcl-2, of intestinal biopsies from cats with histologic evidence of inflammatory bowel disease (IBD) or gastrointestinal (GI) lymphoma was evaluated to determine if expression differed significantly between these two disease processes. Immunolabeling for Bcl-2 was performed on small intestinal endoscopic or full thickness biopsy sections from 55 cats. Diagnosis of IBD, T-cell lymphoma or B-cell lymphoma was established previously. The percentage of infiltrating lymphocytes that were positively labeled for Bcl-2 was subjectively determined for each case. Eight cats were diagnosed with IBD and 47 cats with lymphoma. A significantly higher percentage of cells were positively immunolabeled for Bcl-2 in cats with GI lymphoma [median (range); 90 (5–95)%] compared with cats with IBD [60 (15–95)%] ( P = 0.029). However, the overall degree of positive immunolabeling in both groups tended to be high. This over-expression of Bcl-2 may prove useful as a therapeutic target for IBD and GI lymphoma in cats.

Ultrasonography of small intestinal obstructions: a contemporary approach

OBJECTIVES

To assess the accuracy of intestinal ultrasound for diagnosis of intestinal obstruction in dogs and cats.

METHODS

A prospective clinical study was performed. Inclusion criteria were dogs and cats with clinical signs suggestive of gastrointestinal obstruction. Animals with no obstruction detected on ultrasound were excluded if they could not be monitored for 48 hours to confirm absence of obstruction. Sonographic diagnosis of small intestinal obstruction was based on identification of at least two findings suggestive of intestinal obstruction.

RESULTS

Ninety-two patients suspected of having intestinal obstruction were included. Correct diagnosis of intestinal obstruction was made in 21 cases (23%), and in 68 (74%) this diagnosis was excluded. Interpretation of the images on prospective analysis had sensitivity, positive predictive, specificity and negative predictive values of 100%, 87.5%, 95.8% and 100%, respectively.

CLINICAL SIGNIFICANCE

Ultrasonography is an excellent method for investigation of animals with gastrointestinal disorders, and is particularly useful for excluding obstructive processes.

Feline alimentary lymphoma

Practical relevance Alimentary lymphoma (AL) occurs commonly in cats and exists as distinct subtypes that differ in their clinical course, response to treatment and prognosis. Accurate diagnosis is important to guide appropriate treatment.

Clinical challenges Differentiation of low-grade alimentary lymphoma from lymphoplasmacytic enteritis can be challenging, especially where endoscopic intestinal biopsies, which sample only the mucosa and submucosa, are used. The major differentials for intermediate- and high-grade alimentary lymphoma are other neoplastic and non-neoplastic intestinal mass lesions. The diagnosis of large granular lymphocyte lymphoma requires vigilance as it may be missed with routine diagnostics.

Patient group AL affects predominantly middle- to old-aged domestic crossbred cats (median age 10–13 years).

Evidence base The evidence supporting this review is grade II, III and IV, derived from prospective studies, retrospective case series, reviews, extrapolation from other species, pathophysiological justification and the combined clinical experience of those working in the field.

Feline alimentary lymphoma

Practical relevance Accurate diagnosis of the distinct subtypes of alimentary lymphoma (AL) that occur in cats is important as there are major differences between them in clinical presentation, treatment and prognosis. Unlike intermediate- and high-grade alimentary lymphoma (I/HGAL) and large granular lymphocyte lymphoma (LGLL), which can often be diagnosed by aspiration cytology, full-thickness intestinal biopsies are usually required for the diagnosis of low-grade alimentary lymphoma (LGAL).

Clinical challenges LGAL is an increasingly recognised clinical problem and it can be challenging to differentiate from inflammatory disease. Where there is ambiguity on histology, further diagnostics (immunophenotyping and clonality analysis) may be required. The diagnosis of LGLL requires an index of suspicion as it may be missed with routine diagnostics. While cats with LGAL typically achieve durable remissions with oral prednisolone and chlorambucil, I/HGAL runs a more aggressive clinical course and requires multi-agent chemotherapeutic protocols. Information on the treatment of LGLL is limited and this form of AL has the poorest prognosis. Preliminary studies suggest that abdominal irradiation may potentially be of benefit in cats with AL and further investigations are warranted.

Evidence base The evidence supporting this review is derived from grade II, III and IV prospective studies, retrospective case series, reviews, extrapolation from other species, pathophysiological justification and the combined clinical experience of those working in the field.

Perioperative complications after full-thickness gastrointestinal surgery in cats with alimentary lymphoma

OBJECTIVE

To determine perioperative risk factors for complications that occur before hospital discharge after gastrointestinal (GI) surgery in cats with alimentary lymphosarcoma (LSA).

STUDY DESIGN

Case series.

ANIMALS

Cats (n=70) with a histopathologically confirmed diagnosis of alimentary LSA that had full-thickness GI surgery.

METHODS

Medical record data (February 1996-March 2009) from 3 academic referral centers were reviewed. Retrieved data included signalment, preoperative clinical signs and laboratory findings, perioperative medications administered, type and location of GI surgery performed and outcome until hospital discharge.

RESULTS

In 38 surgeries, intestinal resection and anastomosis was performed. Gastrotomy and/or enterotomy was performed in 53 surgeries. A preoperative serum albumin concentration <2.5 g/dL was recorded for 11 cases. There was no clinical evidence of postoperative leakage from any biopsy or anastomosis site. Postoperative complications that occurred before hospital discharge included: anorexia or decreased appetite (n=8), hyperthermia (3), pancreatitis (1) and constipation (1).

CONCLUSIONS

Cats with alimentary LSA do not appear to be at high risk of postoperative dehiscence after full-thickness GI surgery.

Feline Gastrointestinal Lymphoma

Gastrointestinal lymphomas were identified in 120 cats between 1995 and 2006. Lymphomas were classified according to the World Health Organization (WHO) scheme. Cats with mucosal T-cell lymphoma ( n = 84) predominated and had a median survival of 29 months. Mucosal T-cell lymphoma matched WHO enteropathy-associated T-cell lymphoma (EATCL) type II. Epitheliotropic T-cell infiltrates were present in 62% of cats and occurred as clusters or diffuse infiltrates of small to intermediate-sized T cells in villous and/or crypt epithelium. Similar lymphocytes infiltrated the lamina propria in distinctive patterns. Cats with transmural T-cell lymphoma ( n = 19) had a median survival of 1.5 months. Transmural T-cell lymphoma matched WHO EATCL type I. Epitheliotropic T-cell infiltrates were present in 58% of cats. Large lymphocytes ( n = 11), mostly with cytoplasmic granules (LGL–granzyme B+) ( n = 9) predominated. Transmural extension across the muscularis propria characterized the lesion. Both mucosal and transmural T-cell lymphomas were largely confined to the small intestine, and molecular clonality analysis revealed clonal or oligoclonal rearrangements of T-cell receptor-γ in 90% of cats. Cats with B-cell lymphoma ( n = 19) had a median survival of 3.5 months. B-cell lymphomas occurred as transmural lesions in stomach, jejunum, and ileo–cecal–colic junction. The majority were diffuse, large B-cell lymphomas of centroblastic type. In conclusion, T-cell lymphomas characterized by distinctive mucosal architecture, CD3 expression, and clonal expansion predominated in the feline gastrointestinal tract.

Abdominal irradiation as a rescue therapy for feline gastrointestinal lymphoma: A retrospective study of 11 cats (2001–2008)

In this retrospective study medical records of 11 cats with gastrointestinal lymphoma were evaluated to determine the efficacy of radiation therapy when used in a rescue therapy setting. All cats had relapsed or resistant lymphoma. Two fractions of radiation were delivered over 2 days for a total of 800 cGy. Acute effects of radiation were not noted, except one cat that had a self-limiting loss of appetite. Response was noted in 10/11 cats. Median survival post-radiation therapy was 214 days and the overall median survival in this study was 355 days. This study suggests that abdominal irradiation for feline gastrointestinal lymphoma was well tolerated and may contribute to a positive clinical response.

Chronic inflammatory and non-inflammatory diseases of the gastrointestinal tract in cats: Diagnostic advantages of full-thickness intestinal and extraintestinal biopsies

An evaluation of histological findings in full-thickness biopsies from the gastrointestinal tract (GIT) and extraintestinal samples of 43 cats with chronic GIT disease signs was performed. In the majority of cases (46.5%) inflammatory bowel disease, ie, lymphocytic-plasmacytic enteritis/colitis (32.6%), eosinophilic gastroenterocolitis (11.6%) and mixed inflammatory infiltration (2.3%), was diagnosed. Furthermore, in four animals non-inflammatory mucosal band-shaped fibrosis (9.3%), and in 10 cats (23.3%) a diffuse lymphoma, was found. Six cats displayed only a gastritis (7.0%) or lymphangiectasia (7.0%), respectively. In two cats a mast cell tumour (4.7%) was diagnosed. In one cat no histopathological lesions were found. The availability of transmural biopsies from all segments of the intestine and the collection of extraintestinal samples, especially mesenteric lymph nodes, is especially helpful for diagnosing intestinal tumours such as lymphomas and tumours of mast cell origin.

Low-Grade Alimentary Lymphoma: Clinicopathological Findings and Response to Treatment in 17 Cases

Low-grade alimentary lymphoma (LGAL) was diagnosed by histological and immunohistochemical evaluation of full-thickness biopsies from multiple regions of the gastrointestinal tract collected during exploratory laparotomy in 17 cats. The most common clinical signs were weight loss ( n=17) and vomiting and/or diarrhoea ( n=15). Clinical signs were chronic in 11 cases. Abdominal palpation was abnormal in 12 cats, including diffuse intestinal thickening ( n=8), an abdominal mass due to mesenteric lymph node enlargement ( n=5) and a focal mural intestinal mass ( n=1). The most common ultrasonographic finding was normal or increased intestinal wall thickness with preservation of layering. Ultrasound-guided fine-needle aspirates of mesenteric lymph nodes ( n=9) were incorrectly identified as benign lymphoid hyperplasia in eight cats, in which the histological diagnosis from biopsies was lymphoma. There was neoplastic infiltration of more than one anatomic region of the gastrointestinal tract in 16/17 cats. The jejunum (15/15 cats) and ileum (13/14 cats), followed by the duodenum (10/12 cats), were the most frequently affected sites. Twelve cats were treated with oral prednisolone and high-dose pulse chlorambucil, two with a modified Madison–Wisconsin multiagent protocol and three with a combination of both protocols. Thirteen of the 17 cats (76%) had complete clinical remission with a median remission time of 18.9 months. Cats that achieved complete remission had significantly longer median survival times (19.3 months) than cats that did not achieve complete remission ( n=4) (4.1 months; P=0.019). The prognosis for cats with LGAL treated with oral prednisolone in combination with high-dose pulse chlorambucil is good to excellent.

Feline alimentary lymphoma: demystifying the enigma

Alimentary lymphoma is one of the most commonly diagnosed neoplasms of the cat. The incidence of this disease has increased significantly over the past 15 years during the post-feline leukemia era. Despite the common prevalence of this disease, appropriate diagnosis and treatment can be challenging. There are two main forms of feline alimentary lymphoma: the small-cell (lymphocytic, well-differentiated, low-grade) lymphoma variety and the large-cell (lymphoblastic, high-grade) lymphoma variety. These two diseases are related; however, each presents its own diagnostic and therapeutic challenges. Additionally, it can be difficult to differentiate these malignancies from other nonneoplastic diseases such as inflammatory bowel disease and other chronic inflammatory conditions of the gastrointestinal tract. The purpose of this article is to tackle the challenges of this allusive disease with a step-by-step approach to diagnosis, staging, and therapy.

Immunophenotypic and Histologic Classification of 50 Cases of Feline Gastrointestinal Lymphoma

The purpose of this study was to determine the immunophenotype and histologic classification of 50 cases of feline gastrointestinal lymphoma. Classification was determined using the National Cancer Institute Working Formulation and the Revised European and American Lymphoma/ World Health Organization classification system. Tissue sections were stained with HE, phosphotungstic acid hematoxylin, anti-CD3, anti-CD79a, and anti-BLA.36. Overall, B-cell tumors predominated at 54% (27/50), including 16 diffuse large with immunoblastic nuclear type, 2 diffuse large with centroblastic nuclear type, 3 small lymphocytic, 4 lymphocytic intermediate type, and 2 T-cell-rich large B-cell lymphomas. T-cell tumors comprised 38% (19/50), including 15 epitheliotropic small lymphocytic and 4 lymphoblastic. Three tumors (6%) were nonreactive for B- and T-cell markers and had eosinophilic cytoplasmic granules when stained with HE. Gastric tumors were diagnosed in 24% (12/50) of cats, and 18% (9/50) were present only in the stomach. All gastric lymphomas were of B-cell lineage. Small intestinal lymphoma predominated, with 74% (37/50) of cats affected: T-cell tumors comprised 52% (19/37); 38% (14/37) were B-cell tumors; 8% (3/37) were nonreactive for B- and T-cell markers; and 2% (1/37) expressed both CD3 and BLA.36. Of the 8 cats (16%) that had lymphoma of the large intestine, 88% (7/8) had B-cell tumors and 12% (1/8) had T-cell tumors. The strongest association between gastrointestinal lymphoma immunophenotype, histologic classification, and location occurred in the stomach, where there was a predominance of diffuse large B-cell lymphoma of immunoblastic nuclear type.

Endoscopic diagnosis of diseases causing vomiting

Animals that are chronically throwing up can be diagnostic challenges. Endoscopy can be a useful adjunct in the diagnostic and therapeutic approach to many of these patients; however, it is critical that endoscopic examinations be done properly and carefully. Poorly performed endoscopic examinations can miss important lesions, especially when poor biopsy technique results in inadequate tissue samples for the pathologist. Likewise, rough technique (especially when trying to remove foreign objects) can harm the patient.

Gastric Helicobacter species as a cause of feline gastric lymphoma: a viable hypothesis

Gastric Helicobacter spp. are associated with chronic inflammation and neoplastic transformation in humans as well as domestic and laboratory species. The present study examined the association of Helicobacter heilmannii (Hhe) infection in pet cats with feline gastric mucosa associated lymphoid tissue (MALT) lymphoma. Tissues were collected via gastric biopsy or at necropsy from 47 pet cats with clinical signs of gastrointestinal disease, including vomiting and inappetance, and classified as gastritis (14/47), lymphoma (31/37), or normal (2/47). Tissues positive for argyrophilic organisms with Warthin-Starry stain (29/47) were assessed by fluorescent in situ hybridization (FISH) for the presence of Hhe strains 1-4 as well as with a fifth probe that detected Helicobacter salomonis, Helicobacter bizzozeronii, or Helicobacter felis. A significant association of positive Warthin-Starry status with Hhe infection was found in cases of sick cats (22/29; p<0.05 by Chi-square; chi(2)=7.034). Interestingly, a significant association between Hhe status and a diagnosis of lymphoblastic or lymphocytic lymphoma was observed as well in a subset of 24 Warthin-Starry positive lymphoma cases: of lymphoblastic lymphoma cases, 13/17 were positive for Hhe (p<0.05; chi(2)=4.854). Hhe strains 2 and 4 were most commonly found (18/29 and 17/29, respectively) among sick cats, although a higher than expected number of cats was also positive for Hhe1, which initial reports have described as rare in cats and common in humans. The association found between a positive Hhe status with the presence of feline gastric lymphoma, especially lymphoblastic lymphoma, argues for the need to conduct prospective studies to better identify the frequency and strain distribution of Hhe infection in both healthy and clinically ill cats, particularly those cats with gastric lymphoma.

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.