A case of feline gastrointestinal eosinophilic sclerosing fibroplasia mimicking metastatic neoplasia

Clinicopathological findings, treatment, and outcome in 60 cats with gastrointestinal eosinophilic sclerosing fibroplasia

BACKGROUND

Gastrointestinal eosinophilic sclerosing fibroplasia (GESF) in cats presents as mass(es) associated with the gastrointestinal tract, mesentery, and abdominal lymph nodes.

HYPOTHESIS/OBJECTIVES

To report the clinicopathological findings, treatment, and outcome of cats with GESF.

ANIMALS

Sixty client-owned cats diagnosed with GESF.

METHODS

Retrospective review of medical records of cats with histopathologically confirmed GESF.

RESULTS

The median age was 5.4 years (interquartile range [IQR], 3.3-8.9.); 30% were Domestic Shorthairs and 12% were Domestic Longhair cats, with the most prevalent pedigree breeds being Ragdolls (25%), Exotic Shorthair (10%) and Persian (8%) cats. The median duration of clinical signs was 90 days (IQR, 17.5-247.0); the most common clinical signs were weight loss (60%), hyporexia/anorexia (55%), chronic vomiting (37%), lethargy (35%) and chronic diarrhea (27%). Masses were located in the small intestine (32%), stomach (27%), ileocolic junction (15%), colon (10%), lymph node (8%) and mesentery (8%) and 15% of cats had >1 mass. Eosinophilia was present in 50% and hypoalbuminemia in 28% of cats. The mass was removed surgically in 37% of cases. Most cats (98%) were treated with corticosteroids. Survival was not statistically different between cats treated with surgical resection and cats treated with medical therapy alone, 88% of the cats were still alive at the time of writing.

CONCLUSIONS AND CLINICAL IMPORTANCE

GESF is an important differential diagnosis for abdominal masses in cats, and has a much better prognosis than previously reported.

Abdominal ultrasonographic findings of cats with feline infectious peritonitis: an update

OBJECTIVES

The aim of this study was to describe the abdominal ultrasonographic findings in cats with confirmed or presumed feline infectious peritonitis (FIP).

METHODS

This was a retrospective study performed in an academic veterinary hospital. The diagnosis of FIP was reached on review of history, signalment, clinical presentation, complete blood count, biochemistry panel, peritoneal fluid analysis, cytology and/or histopathology results from abnormal organs, and/or molecular testing (immunohistochemical or FIP coronavirus [FCoV] RT-PCR). Cats with confirmed FIP by molecular testing or with a highly suspicious diagnosis of FIP were included. Abdominal ultrasound examination findings were reviewed.

RESULTS

In total, 25 cats were included. Common clinical signs/pathology findings included hyperglobulinemia (96%), anorexia/hyporexia (80%) and lethargy (56%). Abdominal ultrasound findings included effusion in 88% and lymphadenopathy in 80%. Hepatic changes were noted in 80%, the most common being hepatomegaly (58%) and a hypoechoic liver (48%). Intestinal changes were noted in 68% of cats, characterized by asymmetric wall thickening and/or loss of wall layering, with 52% being ileocecocolic junction and/or colonic in location. Splenic changes were present in 36% of cats, including splenomegaly, mottled parenchyma and hypoechoic nodules. Renal changes were present in 32%, encompassing a hypoechoic subcapsular rim and/or cortical nodules. Mesenteric and peritoneal abnormalities were seen in 28% and 16% of cats, respectively. Most cats (92%) had two or more locations of abdominal abnormalities on ultrasound.

CONCLUSIONS AND RELEVANCE

The present study documents a wider range and distribution of ultrasonographic lesions in cats with FIP than previously reported. The presence of effusion and lymph node, hepatic and/or gastrointestinal tract changes were the most common findings, and most of the cats had a combination of two or more abdominal abnormalities.

Ultrasonography and Sonoelastography Characteristics of Benign vs. Malignant Mesenteric Lymph Nodes in Cats: An Update

(1) Background: Strain elastography (SE) is an ultrasound-based technique able to non-invasively assess tissue elasticity, with malignant tissues being stiffer than normal tissues. The purpose of the study was to evaluate the diagnostic performance of SE to differentiate feline mesenteric benign and malignant lymph nodes (LNs) using a multivariate approach including both SE results and B-mode ultrasound and color Doppler findings. (2) Methods: Feline enlarged mesenteric LNs were evaluated using B-mode ultrasound, color Doppler ultrasonography, and SE. Short-to-long axis ratios, borders, echogenicity, hilum, vascular flow distribution, elastographic patterns, and strain ratios were recorded. Histological and/or cytological diagnosis was available for each LN. (3) Results: A total of 88 LNs were included, 46 (52.3%) benign and 42 (47.7%) malignant; in the benign group, 40 LNs had a diagnosis of reactive hyperplasia (group A) and 6 eosinophilic sclerosing lymphadenitis (group B), while in the malignant group 42 had a diagnosis of lymphoma (group C). The principal component analysis approach showed evidence that by combining B-mode- and color Doppler-based scores with SE scores, the three groups of LNs can be accurately distinguished. (4) Conclusions: Our results demonstrate that a multivariate sonographic approach combining B-mode ultrasound, color Doppler ultrasonography, and SE can accurately distinguish benign from malignant LNs, thus helping in the clinical advice of feline patients.

Intrathoracic eosinophilic sclerosing fibroplasia with intralesional bacteria in a cat

Case summary

A 9-year-old neutered female domestic shorthair cat was presented for investigation of a cranial mediastinal mass. Moderate peripheral eosinophilia and mild-to-moderate polyclonal gammopathy were identified. A thoracoabdominal CT scan documented a cranial mediastinal mass encircling the trachea. Ultrasound-guided fine-needle aspiration and core-needle biopsy were performed, but cytology and histopathology were inconclusive. Surgical debulking was performed. Further histological samples identified severe pyogranulomatous and eosinophilic fibrosing mediastinitis, consistent with feline eosinophilic sclerosing fibroplasia. Gram staining and fluorescence in situ hybridisation (FISH) identified numerous Gram-positive coccoid bacteria. Eosinophilia and hyperglobulinaemia resolved after surgery and combined antimicrobial and immunosuppressive therapy. The cat died 3 months later after developing acute haemorrhagic diarrhoea and dyspnoea.

Relevance and novel information

Eosinophilic sclerosing fibroplasia is reportedly mainly confined to the gastrointestinal tract in cats. Less commonly, extragastrointestinal cases have been described. Lesions in the mediastinal or sternal lymph nodes have been reported, all in association with evident gastrointestinal involvement. The presence of pleural effusion was variable in these cases. To the authors' knowledge, this is the first report of eosinophilic sclerosing fibroplasia presenting due to lower respiratory signs in a cat. Intralesional bacteria were identified using Gram staining and FISH examination. The presence of intralesional bacteria in the normally sterile mediastinal tissue may support the involvement of penetrating injuries in the pathogenesis of the disease. Eosinophilic sclerosing fibroplasia should be suspected in any cat with abdominal and/or thoracic masses, particularly if associated with peripheral eosinophilia and polyclonal gammopathy.

Feline gastrointestinal eosinophilic sclerosing fibroplasia presenting as a rectal mass

Case summary

A 9-year-old neutered male cat was referred owing to dyschezia and weight loss. Abdominal CT revealed a heterogeneous mass in the rectum and thickening of one caudal mesenteric lymph node. The mass induced a focal rectal obstruction. Cytological evaluation of fine-needle aspirates showed signs of mixed inflammation for the rectal mass and a reactive lymph node. Because a definite diagnosis was not achieved, complete resection of the mass via a dorsal approach to the rectum was attempted. Histopathology confirmed complete removal and diagnosed feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF). The cat was treated with psyllium husks and lactulose after surgery. In the postoperative year, the owner reported normal behaviour, food intake and defecation of the patient. Dyschezia reoccurred 14 months after surgery. Imaging revealed recurrence of a rectal mass. Owing to clinical deterioration, the owner elected for euthanasia.

Relevance and novel information

This is the first report of rectal FGESF with dyschezia and weight loss as the main clinical signs. The case demonstrates an acceptable outcome for more than 1 year without additional immunosuppressive therapy, and emphasises that FGESF must be considered as a differential diagnosis for rectal masses in cats.

Feline Gastrointestinal Eosinophilic Sclerosing Fibroplasia—Extracellular Matrix Proteins and TGF-β1 Immunoexpression

Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) has been described as an inflammatory disorder with an eosinophilic component with etiopathogenesis that is still unknown. Sixteen intestinal samples from two veterinary diagnostic services (2014–2017) were included in the study. A histopathological criterion classified the cases into three grades (mild, moderate, and severe) according to the distribution of the lesions and the course. An immunohistochemical study of collagen I, collagen III, fibronectin, and transforming growth factor β1 (TGF-β1) was performed in each case. An immunohistochemical study of mild grades shows greater collagen III immunoexpression, compared to collagen I and fibronectin, which suggests an “early” stage of fibrosis. In more intense grades, an increased immunoexpression of collagen I, compared to collagen III, suggests a “late” stage of fibrosis. Otherwise, the highest expression of TGF-β1 was observed in the moderate phase, due to the high proliferation of reactive fibroblast and intense inflammation. The results suggest that the inflammatory infiltrate is the trigger for the elevation in TGF-β1, altering the collagen type III:I ratio. In conclusion, immunohistochemical studies can be a very useful method in diagnosing cases of FGESF of mild grades and could help to apply a differential diagnosis regarding feline eosinophilic chronic enteritis (CEE) in the context of inflammatory bowel disease (IBD).

Feline abdominal ultrasonography: What's normal? What's abnormal? The diseased gastrointestinal tract

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. B-mode ultrasonography is likely the most widely used modality for imaging the gastrointestinal (GI) tract in cats and it can help in the diagnosis of GI masses, foreign bodies and disorders of the ileocaecocolic junction.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even differentiating between normal variations and pathological changes can be challenging for all but the most experienced. For example, while for inflammatory conditions of the feline GI tract changes are frequently identified on ultrasound, there may occasionally be no changes to the appearance of the intestine; hence a 'normal' ultrasound does not exclude the possibility of inflammatory disease.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, describes the appearance of a range of conditions that affect the feline GI tract; the normal GI tract is addressed in an accompanying article in this issue of JFMS. Aimed at general practitioners who wish to improve their knowledge and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Diagnosis and management of a case of retroperitoneal eosinophilic sclerosing fibroplasia in a cat

Case summary

A 4-year-old neutered male cat was presented with a 2-month history of intermittent constipation that progressed to obstipation. Primary clinical findings included a large, multi lobulated mass in the caudodorsal abdomen, peripheral eosinophilia and hyperglobulinemia. Abdominal imaging revealed a multilobulated, cavitated mass in the sublumbar region. Exploratory celiotomy revealed multiple firm masses in the sublumbar retroperitoneal space causing ventral displacement and compression of the descending colon with extension of the masses into the pelvic canal. Histopathology was consistent with feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF). Aerobic culture was positive for Staphylococcus aureus. The cat was treated with prednisolone (2 mg/kg PO q24h), lactulose (0.5 g/kg PO q8h), amoxicillin/clavulanic acid (62.5 mg/cat PO q12h for 1 month) and fenbendazole (50 mg/kg PO q24h for 5 days). Six months postoperatively, the cat had no recurrence of clinical signs. Repeat evaluation and imaging at day 732 postoperatively revealed marked improvement of the abdominal mass, resolution of peripheral eosinophilia and no clinical signs with continued prednisolone therapy (0.5 mg/kg PO q24h).

Relevance and novel information

This is a report of a primary extramural FGESF lesion, and the first description of characteristics of FGESF on CT. Previous evidence suggests that the most favorable outcomes require immunosuppressive therapy and complete surgical excision; however, this case demonstrates a favorable outcome with medical management alone.

Ultrasonographic, endoscopic and histological appearances of the caecum in cats presenting with chronic clinical signs of caecocolic disease

Objectives

This study aimed to describe the ultrasonographic, endoscopic and histological characteristics of the caecum and ileocaecocolic junction in cats suffering from chronic clinical signs compatible with caecocolic disease.

Methods

Cats presenting with clinical signs suggestive of a caecocolic disease were prospectively recruited. All cats underwent an ultrasonographic examination of the caecum, ileum, colon, ileocolic lymph nodes and local mesenteric fat, in addition to comprehensive abdominal ultrasonography. This was followed by a colonoscopy with a macroscopic assessment of the caecocolic mucosa; caecocolic tissue samples were systematically collected for histologic analysis.

Results

Eighteen cats were included. Eleven of 18 cats had ultrasonographic abnormalities adjacent to the ileocaecocolic junction (lymphadenopathy, local steatitis) and 13/18 cats had abnormalities directly related to the junction (wall thickening, loss of wall layering). Seventeen of 18 cats had at least one ultrasonographic abnormality. Endoscopically, hyperaemia, oedema, discoloration and/or erosions were found in all cats. Each cat was classified as having mild or moderate-to-severe lesions according to endoscopic results; no classification could be established statistically for ultrasonographic results. The accentuation of the dimpled pattern tended to be inversely related to the severity of endoscopic lesion scoring. Histologically, a large proportion of cats showed typhlitis (13/16), one had lymphoma and two were normal. All cats with typhlitis also had colitis. There was only slight agreement between endoscopic and histological caecal results regarding the severity of lesions. Loss of caecal wall layering on ultrasound was found in 7/18 cats and, surprisingly, did not appear as a reliable predictor of the severity of inflammation or of malignancy; neither did local steatitis nor lymph node size.

Conclusions and relevance

Ultrasonography and endoscopy should not be used as the sole methods to investigate the ileocaecocolic region in cats with clinical signs suggestive of caecocolic disease. The presence of chronic clinical signs should routinely prompt histological biopsy.

First report of Cylicospirura felineus in a feral domestic shorthair cat in North America

Case summary

A feral domestic shorthair cat was euthanized owing to acute onset and progression of neurological signs attributed to ethylene glycol toxicity. At post-mortem examination two nodules were identified within the fundus of the stomach. Examination of the gastric nodules revealed an intact mucosal surface, each with multiple red slender nematodes extending through an individual central pore. Histopathological evaluation of the nodules highlighted unique reactive fibroplasia, mimicking feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF), encasing numerous nematodes with females possessing gravid uteri containing abundant larvated eggs. The latter findings were highly suggestive of the Cylicospirura genus, further supported by an en face evaluation of the buccal cavity, highlighting a distinctive trifid tooth appearance. Together, these findings are consistent with Cylicospirura felineus. PCR for the COX-1 gene was unsuccessful on formalin-fixed specimens, attributed to nucleic acid and protein crosslinking.

Relevance and novel information

This represents the first documented case of Cylicospirura species in a feral domestic shorthair cat in North America. This particular cat lived in the highly urban environment of New Orleans, Louisiana. Identification of this case demonstrates the potential for feral cats to serve as reservoir hosts and ultimately support transmission of Cylicospirura species into domesticated cat populations. Gastric cylicospiruriasis may present clinically as a firm abdominal mass, potentially with a history of chronic vomiting. The latter emphasizes the importance of differentiating this condition from a neoplastic process such as alimentary lymphoma and adenocarcinoma. Histologically, the unique thick anastomosing collagenous cords encasing nematodes represent a stereotypical response observed in a broad array of gastrointestinal inflammation in felines, including intralesional bacteria, fungal hyphae, foreign bodies and, in this case, gastric nematodes that closely resemble FGESF. Additionally, these unique histological lesions have previously been misinterpreted as neoplastic conditions, including sclerosing mast cell tumor and extraosseous osteosarcoma.

Feline gastrointestinal eosinophilic sclerosing fibroplasia: 13 cases and review of an emerging clinical entity

Objective:

Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) is a recently described inflammatory disease of cats affecting stomach or intestines and draining regional lymph nodes. This study presents clinical and laboratory data on 13 newly described cases from Australia (11) and the UK (two).

Observations:

The disease was most often observed in middle-aged cats (median 7 years of age; interquartile range 5–9 years). Ragdolls (7/13) and males (9/13) were overrepresented. Cats generally had a long history of vomiting and/or diarrhoea. Lesions were typically large, hard, non-painful, easily palpable and most commonly situated near the pylorus or ileocaecocolic junction. Lesions were heterogeneous ultrasonographically and on sectioning at celiotomy or necropsy. Masses were hard and ‘gritty’ on fine-needle aspiration due to internal trabeculae made up of mature collagen bundles. Bacteria were commonly detected within masses (9/13 cases) using either culture or conventional light microscopy and a panel of special stains, and/or fluorescence in situ hybridisation (FISH), although detection often required a diligent search of multiple tissue sections. A consistent bacterial morphology could not be appreciated among the different cases.

Outcome:

Patients were treated with a variable combination of cytoreduction (debulking and biopsy, to complete surgical resection), immunosuppressive therapy and antimicrobial agents. Many cats had a poor outcome, which was attributable to late diagnosis combined with suboptimal management. It is hoped that suggestions outlined in the discussion may improve clinical outcomes and long-term survival in future cases.