Characterization of gastrointestinal tumors

CT features of gastrointestinal spindle cell, epithelial, and round cell tumors in 41 dogs

There is sparse published information on computed tomographic (CT) characteristics of canine gastrointestinal tumors. The purposes of this multi-center, retrospective, descriptive study were to describe the CT features of histologically-confirmed canine gastrointestinal spindle cell, epithelial, and round cell tumors and, when available, describe the corresponding ultrasound findings. The inclusion criteria were as follows: availability of pre-and post-contrast CT study, and a histopathological diagnosis of the lesions. Recorded parameters were tumor size, location, gastrointestinal wall layers involvement, lesion's growth and enhancement patterns, tumor margination, presence of stenosis, mineralization, ulcerations, lymphadenopathy, or other lesions in the abdomen/thorax. When available, ultrasound images were evaluated. Forty-one dogs met the inclusion criteria and had the following histological diagnoses: 21/41 (51%) spindle cells (7 leiomyomas, 14 leiomyosarcomas/gastrointestinal stromal tumors (GISTs)), 13/41 (32%) epithelial (adenocarcinoma), and 7/41 (17%) round cell (lymphoma) tumors. The growth pattern was concentric, eccentric, and mixed in epithelial, spindle cell, and round cell tumors, respectively. Spindle cell tumors had the largest main volume and involved the outer gastrointestinal layer with an unaffected inner layer. Leiomyosarcomas/GISTs showed irregular margins compared to leiomyomas. Only lymphomas showed multifocal gastrointestinal involvement. Nine carcinomas and six spindle cell tumors caused partial stenosis with secondary sub-obstruction. Mineralizations were more frequent in spindle cell tumors (10/21) and absent in lymphomas. Lymphadenomegaly was widespread in lymphomas, regional in leiomyosarcomas-GISTs and adenocarcinomas, and absent in leiomyomas. The reported CT features may be useful in prioritizing the differential diagnosis between spindle cell, epithelial, and round cell tumors, similar to those reported on ultrasound.

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.

Comparison of the clinical, ultrasound, and CT findings in 13 dogs with gastric neoplasia

Diagnosis of gastric tumors in dogs is difficult and is often obtained by biopsy following identification of a mass through ultrasound (US) or endoscopy. In human medicine, modalities such as CT and endoscopy are standard of care in the diagnosis and staging of gastric tumors. Although one veterinary study has described CT findings of gastric tumors in dogs using iatrogenic gas dilation, there are no veterinary studies that have directly compared the usefulness of US versus CT in the diagnosis and staging of these tumors. This retrospective, descriptive study evaluated US and CT images from 13 dogs. Gastric tumor diagnoses included leiomyoma (n = 4), adenocarcinoma (n = 3), leiomyosarcoma (n = 3), gastrointestinal stromal tumor (n = 2), and lymphoma (n = 1). Computed tomography was successful in identification of 92% of gastric tumors, while US identified only 69%. Computed tomography identified more locations of lymphadenopathy and correctly identified the location of gastric tumors more frequently than US when compared to the surgical, endoscopic, or necropsy reports. Most features seen on US and CT overlapped between the different tumor types. Lymphoma had a lower mean attenuation in CT than the other gastric tumors and was the only gastric tumor to not have complete loss of the gastric wall layering on US. As expected, adenocarcinoma appeared as gastric wall thickening with regional lymphadenopathy. Findings supported using CT as an ancillary diagnostic test for characterizing and staging gastric tumors in dogs and assisting in the selection of surgical candidates.

B-Mode and Contrast Enhanced Ultrasonography Features of Gastric Inflammatory and Neoplastic Diseases in Dogs

Simple Summary

Canine gastric disorders are common in veterinary clinical practice and among these neoplasms require rapid identification and characterization. Standard ultrasonography is the imaging modality of choice for gastric wall assessment. The aim of this prospective study is to describe the specific B-mode and contrast enhanced ultrasound features of normal, inflammatory, and neoplastic gastric diseases in dogs. Standard and contrast enhanced ultrasound of the stomach were performed in anesthetized dogs with or without gastric disorders. Gastric wall qualitative and quantitative parameters were evaluated. A total of 41 dogs were included: 6 healthy as the control group; 9 gastritis; 8 adenocarcinoma; 8 alimentary lymphoma; 4 leiomyosarcoma; 2 gastrointestinal stromal tumor; 2 leiomyoma; 1 undifferentiated sarcoma; 1 metastatic gastric hemangiosarcoma. Gastric tumors appear as a marked thickening with absent layers definition and possible regional lymphadenopathy and steatitis while gastritis generally shows no/mild thickening and no other alterations on standard ultrasound. During contrast—enhanced ultrasonography, neoplasms show a higher and faster wash in if compared to that of gastritis. B-mode and contrast enhanced ultrasound assessment may be useful in the evaluation of canine gastric disorders for the distinction between gastritis and gastric neoplasms, even if there are no specific aspects able to discriminate between different tumors types.

Abstract

Canine gastric disorders are common in veterinary clinical practice and among these neoplasms require rapid identification and characterization. Standard ultrasound (US) is the imaging modality of choice for gastric wall assessment. The aim of this prospective study is to describe the specific B-mode and contrast enhanced US (CEUS) features of normal, inflammatory, and neoplastic gastric wall in dogs. B-mode US and CEUS of the stomach were performed in anesthetized dogs with or without gastric disorders. Gastric wall qualitative and quantitative parameters were evaluated on B-mode US and CEUS examination. A total of 41 dogs were included: 6 healthy (HEA) as the control group; 9 gastritis (INF); 8 adenocarcinoma (AC); 8 alimentary lymphoma (AL); 4 leiomyosarcoma (LEIS); 2 gastrointestinal stromal tumor (GIST); 2 leiomyoma; 1 undifferentiated sarcoma; 1 metastatic gastric hemangiosarcoma. Gastric tumors appear as a marked wall thickness with absent layers definition and possible regional lymphadenopathy (AC and AL) and steatitis (AC) while gastritis generally shows no/mild thickening and no other alterations on B-mode US. On CEUS, neoplasm shows a higher and faster wash in if compared to that of gastritis. B-mode and CEUS assessment may be useful in the evaluation of canine gastric disorders in the distinction between gastritis and gastric neoplasms, even if there are no specific features able to discriminate between the different tumor histotypes.

B-Mode and Contrast Enhanced Ultrasonography Features of Gastric Inflammatory and Neoplastic Diseases in Cats

Simple Summary

Alimentary lymphoma is the most common neoplasm of the feline gastrointestinal tract. In most cases, standard ultrasonography may not be able to discriminate between a neoplastic and inflammatory infiltrate at this level. The aim of this prospective study is to establish the value of conventional ultrasound and contrast enhanced ultrasonography in describing specific features of normal, inflammatory, and neoplastic gastric diseases in feline species. A total of 29 cats were included in the study: six healthy cats as the control group; nine with gastric inflammation; three with low-grade alimentary lymphoma; 10 with high grade alimentary lymphoma. High-grade lymphoma usually appears as a severe wall thickening with absent layer definition, regional lymphadenopathy and local steatitis on a conventional ultrasound and shows a high-contrast uptake and a homogeneous enhancement with comb teeth-like vessels on contrast-enhanced ultrasound, while gastric inflammation and low-grade alimentary lymphoma showed a large overlap on both of those two ultrasonographic techniques. Diagnostic accuracy and cut-off value were calculated and found to be relevant for thickness (3.8 mm) for inflammation vs. low-grade lymphoma and “benign” vs. “malignant” as well as peak enhancement (34.87 dB) for “benign” vs. “malignant”. Thickness and peak enhancement can be useful parameters in the characterization of gastric infiltrates in cats.

Abstract

Alimentary lymphoma (AL) is the most common malignancy of the feline gastrointestinal tract and may cause variable mild to severe alteration of the gastric wall on ultrasonography (US) that can be very similar to those caused by inflammation (INF). The aim of this prospective study is to establish the value of B-mode and contrast-enhanced US (CEUS) in describing specific features of normal, inflammatory, and neoplastic gastric diseases in feline species. B-mode US and CEUS of the stomach were performed in anesthetized cats with or without gastric disorders. Gastric wall qualitative and quantitative parameters were evaluated on B-mode US and CEUS examination. A total of 29 cats were included: six healthy (HEA) cats as the control group; nine INF; three low-grade lymphoma (LGAL); 10 high-grade lymphoma (HGAL). On B-mode US, there were significant differences in thickness, the wall’s layer definition and echogenicity between HGAL and all the other groups (<0.001). For CEUS, statistical differences between groups were found in the following: HGAL vs. HEA, HGAL vs. INF; HGAL vs. LGAL; INF vs. HEA. Diagnostic accuracy (AUC) and cut-off value were calculated and found to be significant for thickness (3.8 mm) for INF vs. LGAL (AUC > 0.70) and “benign” vs. “malignant” (AUC > 0.90) as well as peak enhancement (34.87 dB) for “benign” vs. “malignant” (AUC > 0.70). INF and LGAL showed an overlap of qualitative and quantitative parameters both on B-mode and CEUS, while HGAL usually appears as a severe wall thickening with absent layer definition, high-contrast uptake, a specific enhancement pattern, regional lymphadenopathy and local steatitis. Thickness and peak enhancement can be useful parameters in the characterization of gastric infiltrates in cats.

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.

Correlation between Preoperative Ultrasonographic Findings and Clinical, Intraoperative, Cytopathological, and Histopathological Diagnosis of Acute Abdomen Syndrome in 50 Dogs and Cats

Acute abdomen syndrome is an emergency in small animal practice that requires rapid diagnosis to determine the appropriate treatment. No studies have correlated the preoperative abdominal ultrasonography (US) findings with the clinical, surgical, cytopathologic, and histopathologic findings. This retrospective study was designed to evaluate abdominal US in the diagnosis of acute abdomen syndrome using surgery as a "criterion standard". The most frequently misinterpreted lesions with US were also identified. The study included 50 dogs and cats with physical examination, an US diagnosis, US guided fine-needle aspiration cytology, intraoperative findings, and histopathology. Intraoperatively, 49 primary and 43 secondary lesions were identified. The sensitivity, specificity, and positive and negative predictive values for US were calculated. There was a good agreement between the US diagnosis and intraoperative findings of 86.9% (80/92), for both primary and secondary lesions (p < 0.0001). Cytology and histopathology examinations corroborated the US in 86.4% (n = 64/74) of primary and 66.2% of secondary (n = 49/79) lesions. Using US as the "criterion standard", the sensitivity of abdominal palpation for identification of ascites and masses was 32.4% and 43.7%, respectively, while the specificity was 93.7% and 94.4%, respectively. Abdominal US is a useful preoperative modality for diagnosing acute abdominal diseases in dogs and cats. Care should be taken with interpretation of gastrointestinal perforation, omental tumors, and common bile duct rupture, as these lesions are frequently misinterpreted with US.

Gastric carcinoma in canines and humans, a review

Gastric carcinoma (GC) is the most common neoplasm in the stomach of dogs. Although incidence in the general population is reported to be low, breed-specific GC has a high incidence. Median age at presentation ranges from 8 to approximately 10 years. The disease is mostly located in the lesser curvature and antropyloric region of the stomach. Unfortunately, diagnosis is usually made when the disease is at an advanced stage and, therefore, prognosis is poor. Due to similarities in clinical presentation, diagnosis, histology and prognosis, canine GC may serve as a valuable model for human GC. Extensive pedigrees of canine gastric carcinoma cases could reveal insights for human gastric carcinoma. Putative species differences include the role of Helicobacter in pathogenesis, the wide array of genetic data and screening available for humans, and treatment protocols that are available for human GC.

Imaging diagnosis--ultrasonographic appearance of small bowel metastasis from canine mammary carcinoma

A 10-year-old entire female Beagle dog was evaluated for an acute history of lethargy, anorexia, and diarrhea. Mammary tumors were detected during physical examination. Ultrasonographic scanning revealed the presence of a unique pattern of multiple, well-defined and well-marginated hypoechoic nodules in the muscularis layer of the jejunum. These nodules were not associated with changes in the rest of the normal intestinal layering and were not causing signs of intestinal obstruction. Mammary carcinoma metastases to the intestinal muscularis layer were diagnosed based on histopathological examination.

Ultrasonographic appearance of lymphomatous infiltration of the abomasum in cows with lymphoma

CASE DESCRIPTION

4 adult Holstein dairy cows were examined for anorexia and decreased milk production.

CLINICAL FINDINGS

Clinical signs included abdominal distension, normal to decreased ruminal motility, and decreased fecal output. Hypochloremia and high BUN concentration were also noted on serum biochemical analysis. Transabdominal ultrasonography revealed abnormal thickening of the abomasum with pyloric thickening and loss of the typical layered appearance of the pyloric wall. Results of cytologic examination of fine-needle aspirates of the abnormal portion of the abomasum were compatible with a diagnosis of lymphoma in 3 cows.

OUTCOME

The diagnosis of lymphoma involving the abomasum was confirmed by exploratory laparotomy, necropsy, or slaughterhouse reports. Two cows were euthanatized, 1 died 5 days after the diagnosis, and 1 was sent to the slaughterhouse, but the carcass was discarded because of generalized lymphoma.

CLINICAL RELEVANCE

Transabdominal ultrasonography is a noninvasive portable test that can be useful for the diagnosis of lymphomatous infiltration of the pyloric portion of the abomasum, which may result in obstruction. This can be especially useful to avoid unnecessary treatments when no typical signs of enzootic lymphoma are present. Percutaneous fine-needle aspiration of the abnormally thickened abomasal wall should be performed. These procedures can enable diagnosis of this neoplasm, which has a relatively poor prognosis, thus avoiding the unnecessary costs incurred by exploratory laparotomy.

Ultrasonographic appearance of canine gastric polyps

Benign gastric polyps are uncommon in dogs and most are discovered incidentally. Polyps protruding into the pyloric antrum can cause gastric outflow obstruction. Clinical and ultrasonographic findings in seven dogs with histologically confirmed benign mucosal gastric polyps were reviewed. Sonographic findings such as shape, size, echogenicity, location, evidence of gastric wall thickening, wall layering, and size of regional lymph nodes were recorded. Five sessile and two pedunculated masses of different sizes (range 7-60 mm) and echogenicities were found. They primarily arose from the mucosal layer and protruded into the gastric lumen. Only one dog had a large inhomogeneous mass with a poorly visualized gastric wall layering. The polyps were all single, and were located in the pyloric antrum in six out of seven dogs. Although the ultrasonographic appearance allowed a presumptive diagnosis of mucosal gastric polyp, the final diagnosis was determined from histopathologic examination.

Ultrasonographic evaluation of the thickness of the small intestinal wall in dogs with inflammatory bowel disease

OBJECTIVES

To establish whether the intestinal wall thickness, as measured ultrasonographically, is significantly increased in dogs with inflammatory bowel disease (IBD). The results would provide the information necessary to decide whether measurement of ultrasonographic wall thickness can predict IBD in dogs.

METHODS

The intestinal wall thickness of 75 dogs with idiopathic IBD, as measured by ultrasonography, was compared with recently published normal values. IBD was either confirmed histologically (n = 54) or suspected (n = 21). In all cases there was a positive response to immunosuppressive treatment.

RESULTS

A positive association between intestinal wall thickness in dogs and either the histological diagnosis or the response to treatment was not found. Ultrasonographic intestinal wall measurements do not appear to be able to establish a diagnosis of intestinal inflammation and may result in a false negative diagnosis in cases of IBD.

CLINICAL SIGNIFICANCE

The same 'grey zone' of between 4 and 6 mm used in humans can be used in the canine duodenum to distinguish the normal range, reserving the term 'abnormal' for an intestinal measurement greater than 6 mm in the duodenum and greater than 4.7 mm in the jejunum.

Ultrasonographic and pathologic features of intestinal smooth muscle hypertrophy in four cats

The ultrasonographic findings for four cats with intestinal smooth muscle hypertrophy are described. In two cats, intestinal smooth muscle hypertrophy was associated with chronic enteritis. In the remaining two cats, intestinal smooth muscle hypertrophy affected the intestinal tract proximal to stenosis due to alimentary lymphoma and an intestinal foreign body, respectively. Moderate increased thickness of the affected intestinal wall, measuring 7-8 mm, was evident on abdominal ultrasonographic examination of all subjects. In addition, the ultrasonographic five-layered feature of the intestinal wall was maintained, and only the muscular layer appeared thickened. Abdominal ultrasound allowed a presumptive diagnosis of intestinal smooth muscle hypertrophy that was confirmed histologically in all cats.

Diagnostic value of ultrasonography in differentiating enteritis from intestinal neoplasia in dogs

One hundred and fifty dogs with histopathologically confirmed intestinal disease were evaluated retrospectively. Sixty-one dogs had enteritis and 89 dogs had intestinal neoplasia. Ultrasonographic findings including the thickness and distribution of the intestinal lesion, the integrity of intestinal wall layering, regional lymph node thickness, the location of the intestinal segment involved, and regional motility were evaluated. Dogs with intestinal tumor had wall thickness (1.5 cm) significantly greater than dogs with NSE lesions (0.6 cm; p < 0.001). Ninety-nine percent of dogs with intestinal tumor had loss of wall layering while 88% of dogs with NSE had normal or altered wall layering (p < 0.001). Dogs with NSE were significantly more likely to have diffuse lesion (72%) than dogs with intestinal tumor (2%; p < 0.001). Lymph node median thickness in 24/61 dogs with NSE was 1.00 cm. The median thickness of the lymph nodes in 56/89 dogs with intestinal tumors was 1.9 cm. A multivariate analysis showed that loss of wall layering alone was an excellent predictive factor in differentiating intestinal tumor from NSE. In our population, dogs with loss of intestinal wall layering were 50.9 times more likely to have a tumor than enteritis.

Gastrointestinal stromal tumors and leiomyomas in the dog: a histopathologic, immunohistochemical, and molecular genetic study of 50 cases

Fifty canine gastrointestinal (GI) mesenchymal tumors were examined to determine the occurrence of leiomyomas (LM) and GI stromal tumors and to compare their clinicopathologic features. Twenty-one tumors (42%) were histologically reclassified as gastrointestinal stromal tumors (GISTs) and 29 tumors (58%) as LMs on the basis of their histologic similarity with homologous human tumors. The GISTs occurred equally in males and females, with a mean age of 11 years (range 5-14 years). Five GISTs (24%) were associated with clinical signs and six (29%) had metastasis in liver or abdominal cavity. The GISTs occurred in large intestine (10, 48%), small bowel (six, 29%), stomach (four, 19%), and mesentery of small intestine (one, 5%). Histologically, they were highly cellular spindle, or less commonly epithelioid tumors with mitotic rates ranging from 0 to 19 per 10 HPF. Eleven tumors (52%) were positive for CD117 (KIT); seven (33%) were positive for smooth muscle actin but none for desmin and S-100 protein. Sequences of KIT exon 11, often mutated in human GISTs, were evaluated from four GISTs. Deletion of Try556-Lys557 coexisting with duplication of Gln555 in one case of GIST and T to C transition resulting in substitution of Pro for Leu575 in another were identified. The LMs occurred predominantly in males (82%) with a mean age of 11 years (range 8-17 years). Nine tumors (31%) had associated clinical signs. They occurred in the stomach (22, 76%), esophagus (four, 14%), and intestines (three, 10%); all were paucicellular, had no mitoses, and were composed of mature smooth muscle cells. Twenty-eight (97%) were positive for smooth muscle actin and 18 (62%) for desmin but none for CD117 and S-100. Both GISTs and true LMs occur in the GI tract of dogs. Both tumors have distinctive pathologic features.

Ultrasonographic and clinicopathologic findings in 21 dogs with intestinal adenocarcinoma

In a retrospective study of 21 dogs with intestinal adenocarcinoma, the signalment, clinical presentation, laboratory findings, ultrasonographic features, treatment, and outcome were reviewed. Anorexia (n = 16), vomiting (n = 15), diarrhea (n = 10), and weight loss (n = 9) were the most common clinical signs reported. Ultrasonographic features that were evaluated included location, length, wall thickness, echogenicity, regional motility, layering, regional lymphadenopathy, and fluid accumulation proximal to the lesion site. All lesions were transmural and associated with complete loss of wall layering. Maximum wall thickening at the lesion site ranged from 7 to 17 mm (median 12 mm, mean 11.9 mm). Most of the dogs had a lesion measuring from 23 to 63 mm in length, (median 40 mm, mean 42 mm). Most intestinal lesions were poorly echogenic and had an irregular lumen. Fluid accumulation proximal to the lesion site was identified in 17 of 21 dogs, and in 13 of 17 dogs the fluid accumulation was considered moderate to severe. Regional lymphadenopathy and/or nodular mesentery/omentum were noted in 12 of 21 dogs. The tumor was located in small intestine for 15 dogs and in the colon for the remaining 6 dogs. Fifteen dogs were treated by surgical resection of the intestinal mass. Their median survival time was 233 days. Only gender appeared to influence survival. Female dogs lived a median of 28 days, whereas male dogs lived a median of 272 days.

Multicentric lymphoma with intestinal involvement in a dog

A 5-year-old, male German shepherd dog was evaluated for a 5-week history of vomiting, diarrhea, lethargy, and weight loss. In abdominal radiographs, there was an unusual corrugated appearance within a loop of intestine. Sonographically, this loop also had a similar corrugated appearance with alternating hyperechoic and hypoechoic bands. Lymph nodes within the abdomen and thorax were enlarged, and a thoracic mass was also detected. Ultrasound-guided fine-needle aspirates of the mesenteric lymph nodes were highly suggestive of lymphoma. After postmortem examination, a diagnosis of multicentric lymphoma with involvement of the gastrointestinal tract was made.