Diffuse Lymphoplasmacytic Infiltration Research Articles

Sclerosing cholecystitis associated with autoimmune pancreatitis

To evaluate the histopathological and radiological findings of the gallbladder in patients with autoimmune pancreatitis (AIP). The radiological findings of the gallbladder of 19 AIP patients were retrospectively reviewed. Resected gallbladders of 8 AIP patients were examined histologically and were immunostained with anti-IgG4 antibody. Controls consisted of gallbladders resected for symptomatic gallstones (n = 10) and those removed during pancreatoduodenectomy for pancreatic carcinoma (n = 10), as well as extrahepatic bile ducts and pancreases removed by pancreatoduodenectomy for pancreatic carcinoma (n = 10). Thickening of the gallbladder wall was detected by ultrasound and/or computed tomography in 10 patients with AIP (3 severe and 7 moderate); in these patients severe stenosis of the extrahepatic bile duct was also noted. Histologically, thickening of the gallbladder was detected in 6 of 8 (75%) patients with AIP; 4 cases had transmural lymphoplasmacytic infiltration with fibrosis, and 2 cases had mucosal-based lymphoplasmacytic infiltration. Considerable transmural thickening of the extrahepatic bile duct wall with dense fibrosis and diffuse lymphoplasmacytic infiltration was detected in 7 patients. Immunohistochemically, severe or moderate infiltration of IgG4-positive plasma cells was detected in the gallbladder, bile duct, and pancreas of all 8 patients, but was not detected in controls. Gallbladder wall thickening with fibrosis and abundant infiltration of IgG4-positive plasma cells is frequently detected in patients with AIP. We propose the use of a new term, sclerosing cholecystitis, for these cases that are induced by the same mechanism as sclerosing pancreatitis or sclerosing cholangitis in AIP.

A case of retroperitoneal and mediastinal fibrosis exhibiting elevated levels of IgG4 in the absence of sclerosing pancreatitis (autoimmune pancreatitis)

There is now increasing evidence that IgG4 is closely involved in idiopathic sclerosing lesions, such as sclerosing pancreatitis and sclerosing sialadenitis. In this report, we describe a case of IgG4-related retroperitoneal and mediastinal fibroses. A 52-year-old man presented with dull back pain and was found to have a continuously surrounding paraaortic mass. A biopsy specimen taken from the retroperitoneum showed a diffuse lymphoplasmacytic infiltration intermixed with fibrosis. Many IgG4-positive plasma cells were demonstrated on immunostaining. His serum IgG4 concentration was 392 mg/dL (reference range, <70). We treated this patient with a corticosteroid, which markedly diminished the paraaortic mass along with lowering of his serum IgG4 concentration. The possible involvement of IgG4 was suggested in the pathogeneses of retroperitoneal and mediastinal fibroses in this patient. IgG4 might be useful in the clinical management of retroperitoneal or mediastinal fibrosis to differentiate them from malignant tumors and predict steroid sensitivity.

Molecular Analysis in a Patient With Waldenström's Macroglobulinemia Reveals a Rare Case of Biclonality.

Background: The immunoglobulin and T-cell receptor gene rearrangement test is used to identify monoclonal populations in B- and T-cell malignancies and has become an important adjunct to morphologic analysis and immunophenotyping by flow cytometry. Waldenström's macroglobulinemia (WM) is typically a monoclonal proliferation of B cells with morphology of plasmacytoid lymphocytes and production of monoclonal IgM. Methods and Results: We report a case of WM with biclonal gammopathy (IgM kappa and IgM lambda) involving the blood and a diffuse lymphoplasmacytic infiltrate in the bone marrow in an 83-year-old man. Immunophenotyping of the blood and bone marrow aspirate revealed B cells expressing IgM lambda surface immunoglobulins and CD5+, CD19+, and CD20+ surface markers. Gene-rearrangement analysis with the Southern blot technique revealed multiple rearranged bands in each lane of restricted patient DNA after probing with both immunoglobulin heavy (J(H))- and light (J(kappa))-chain gene probes. Conclusions: Biclonal gammopathy in WM and biclonal B-cell proliferations as determined by gene-rearrangement studies are rare entities, and few evaluations of them are reported in the literature. To our knowledge, this case is the first one of biclonal WM to have been evaluated by serum protein immunofixation, immunohistologic staining, immunophenotyping by flow cytometry, and immunoglobulin gene-rearrangement analysis.

Autoimmune Pancreatitis With Hepatic Inflammatory Pseudotumor

We report a case of autoimmune pancreatitis (AIP) with hepatic inflammatory pseudotumor (IP). The patient was clinically diagnosed as having multiple metastatic tumors originated from cholangiocellular carcinoma as well as autoimmune pancreatitis and underwent left lobectomy of the liver. Histological examination showed a diffuse or dense lymphoplasmacytic infiltration with obliterating phlebitis but an absence of neoplastic proliferation both in the liver tumor and in the biopsy specimen of the pancreas. Abundant IgG4-positive plasma cells were seen in the lesions. This is the first case report that shows a simultaneous occurrence of hepatic IP and AIP, suggesting that these lesions appeared on the background of the recently proposed entity of IgG4-related systemic disease.

ENDOSONOGRAPHIC FEATURES OF LYMPHOPLASMACYTIC SCLEROSING PANCREATITIS

The role of endoscopic ultrasound (EUS) in the evaluation of pancreatic disorders is well established. However, little information on the endosonographic features of uncommon pancreatic diseases is available. We describe the case of a rare form of autoimmune chronic pancreatitis evaluated with EUS. Clinical Vignette: A 31 year-old Mexican male was referred to our institution with jaundice and a common bile duct (CBD) stricture on endoscopic retrograde cholangiopancreatography (ERCP). The patient described a three-month history of malaise, abdominal pain, a forty-pound weight loss, and the recent onset of jaundice; on ERCP he had a 6 cm distal biliary stricture with proximal dilation of the biliary tree. EUS was performed revealing severe changes of chronic pancreatitis including marked lobularity, prominent interlobular septae and a diffusely inhomogeneous echo pattern, features suggestive of diffuse fibrosis. The pancreatic duct was hardly visible. At the level of the pancreatic head, these changes coalesced into a mass-like lesion which involved the distal CBD and produced near-complete biliary obstruction. No lymphadenopathy was present. Concerned for the possibility of an underlying malignancy, no EUS-guided fine needle aspiration (FNA) was performed and the patient was taken for pancreaticoduodenectomy. Histopathologic examination of the surgical specimen demonstrated diffuse lymphoplasmacytic infiltration of the pancreas with marked acinar atrophy, obliterated phlebitis, and extensive fibrosis. The CBD and gallbladder showed marked inflammatory wall thickness. These features were compatible with lymphoplasmacytic sclerosing pancreatitis (LPSP). Serologic markers for autoimmune disease were negative. The patient recovered satisfactorily from the procedure and was discharged home. His follow-up at 21 months has included the development of insulin-requiring diabetes, an episode of acute pancreatitis of the remaining gland, and the need for chronic immunosuppressive therapy. Conclusion: Lymphoplasmacytic sclerosing pancreatitis is a rare form of autoimmune pancreatitis that can only be accurately diagnosed with histopathology. However, the clinical and endosonographic features (including the information obtained with EUS-guided FNA) can provide important clues to consider this disease in the differential diagnosis of patients with chronic pancreatic disorders.

Autoimmune pancreatitis

A 65-year-old man was referred because of obstructive jaundice and epigastric pain. Serum total bilirubin level was 14.4 mg/dL (normal: <1.0 mg/dL), and Dupan II level was 290 U/mL (<150 U/mL). Abdominal US showed a 40-mm hypoechoic mass within the head of the pancreas and a dilatation of the extra- and intrahepatic biliary system (A). At ERCP, there was stenosis of the lower bile duct and the main pancreatic duct (B). Angiography revealed encasement of the dorsal pancreatic artery and stenosis of the portal vein (C). Radiologic imaging studies were highly suggestive of cancer of the head of the pancreas. A firm mass, involving most of the pancreatic head, adherent to the portal vein, and swelling of peripancreatic lymph nodes, up to 20 mm in diameter, was seen at the operation. Although frozen sections of needle biopsy specimens could not confirm cancer cells, surgeons felt that the tumor was pancreatic cancer, and a pancreatoduodenectomy was performed. Microscopic evaluation demonstrated diffuse lymphoplasmacytic infiltration with marked interstitial fibrosis (D; H&E, orig. mag. ×100). A histopathologic diagnosis was made of autoimmune pancreatitis. Because steroid therapy is effective for autoimmune pancreatitis, this possibility should not be overlooked in the relatively elderly patient with obstructive jaundice suggestive of pancreatic cancer. View Large Image Figure Viewer View Large Image Figure Viewer View Large Image Figure Viewer

Idiopathic chronic pancreatitis with periductal lymphoplasmacytic infiltration: clinicopathologic features of 35 cases.

To clarify clinicopathologic features of idiopathic chronic pancreatitis with lymphoplasmacytic infiltration, we carried out a study of 35 cases. There were two histologic groups, which we have designated lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-centric chronic pancreatitis. Lymphoplasmacytic sclerosing pancreatitis (22 cases) was a fibrosing process with diffuse lymphoplasmacytic infiltrates involving pancreatic lobules and ducts, adipose tissue, blood vessels, and common bile duct. Obliterative phlebitis was found in every case except for one. The histologic features were similar to other idiopathic fibrosclerosing disorders, and one patient also had retroperitoneal fibrosis. Affected patients tended to be elderly men. Idiopathic duct-centric chronic pancreatitis (13 cases) was characterized by inflammatory infiltrates (including neutrophils) that were denser in the lobules than in interlobular fibrotic areas. Neutrophils were also prominent in the ducts, and destruction of the duct epithelium was commonly seen. Patient ages were more broadly distributed than in lymphoplasmacytic sclerosing pancreatitis. Two patients had inflammatory bowel disease. We conclude that idiopathic chronic pancreatitis with lymphoplasmacytic infiltration, sometimes called autoimmune pancreatitis, consists of at least two different processes. One of these, lymphoplasmacytic sclerosing pancreatitis, is a histologically unique lesion and could be a pancreatic manifestation of idiopathic fibrosclerosing disorders.

Autoimmune Gastritis: Distinct Histological and Immunohistochemical Findings Before Complete Loss of Oxyntic Glands

Autoimmune gastritis (AG) can be easily recognized when the histological features are fully developed, but recognizing AG before the complete loss of the oxyntic mucosa is more challenging. One feature of fully developed AG is enterochromaffin cell-like (ECL) hyperplasia, but its presence or absence in earlier stages of AG has not been fully evaluated. A retrospective study of biopsy specimens from 40 patients was performed; all of the patients were originally diagnosed with possible AG based on the presence of lymphocytic infiltration and damage to oxyntic glands and/or the presence of metaplastic epithelium that disproportionately involved the body mucosa. Nineteen cases had follow-up serological studies for anti–parietal cells and/or anti–intrinsic factor antibodies: 13 were positive and 6 negative. The remaining 21 cases were indeterminate because of incomplete testing. The histological findings were similar in the patients who were serologically positive and those who were indeterminate for AG. In all of these cases, the oxyntic mucosa showed lymphoplasmacytic infiltrates within the lamina propria with focal gland infiltration and damage. Sixty-five percent (22/34) of the cases showed intestinal and/or pyloric metaplasia, and 85% (29/34) showed parietal cell pseudohypertrophy. Chromogranin stains were performed in 11 of 13 cases with positive serological markers for AG, and all showed at least linear ECL cell hyperplasia. In contrast, none of the six cases with negative serological studies had linear ECL cell hyperplasia, P < .001. In conclusion, the following constellation of findings supports a diagnosis of AG before the complete loss of oxyntic mucosa: deep or diffuse lymphoplasmacytic infiltrates within the lamina propria with foci of gland infiltration and damage, epithelial metaplasia, parietal cell pseudohypertrophy, and ECL cell hyperplasia at the linear or greater level.

Molecular analysis in a patient with waldenstrom's macroglobulinemia reveals a rare case of biclonality

Background: The immunoglobulin and T-cell receptor gene rearrangement test is used to identify monoclonal populations in B- and T-cell malignancies and has become an important adjunct to morphologic analysis and immunophenotyping by flow cytometry. Waldenström's macroglobulinemia (WM) is typically a monoclonal proliferation of B cells with morphology of plasmacytoid lymphocytes and production of monoclonal IgM. Methods and Results: We report a case of WM with biclonal gammopathy (IgM kappa and IgM lambda) involving the blood and a diffuse lymphoplasmacytic infiltrate in the bone marrow in an 83-year-old man. Immunophenotyping of the blood and bone marrow aspirate revealed B cells expressing IgM lambda surface immunoglobulins and CD5+, CD19+, and CD20+ surface markers. Gene-rearrangement analysis with the Southern blot technique revealed multiple rearranged bands in each lane of restricted patient DNA after probing with both immunoglobulin heavy (J H)- and light (J kappa)-chain gene probes. Conclusions: Biclonal gammopathy in WM and biclonal B-cell proliferations as determined by gene-rearrangement studies are rare entities, and few evaluations of them are reported in the literature. To our knowledge, this case is the first one of biclonal WM to have been evaluated by serum protein immunofixation, immunohistologic staining, immunophenotyping by flow cytometry, and immunoglobulin gene-rearrangement analysis. (Mol Diagn 1996 Sep;1(3):159-166)

Primary small-intestinal lymphomas in Taiwan: immunoproliferative small-intestinal disease and nonimmunoproliferative small-intestinal disease.

The clinicopathologic findings in 45 adult Chinese patients with primary small-intestinal lymphoma (PSIL) are described and compared with those in Western countries and in underdeveloped nations. The efficacy of combination chemotherapy is also assessed. Six patients had immunoproliferative small-intestinal disease (IPSID) indicated by the presence of alpha-heavy chain protein (alpha-CP) in body fluids or tumor tissues. Thirty-nine patients had non-IPSID, including one with postrenal transplant lymphoma. Thirty-three non-IPSID patients received a minimum of four cycles of combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP). All IPSID patients presented with the clinical and laboratory features of severe intestinal malabsorption, and all had diffuse lymphoplasmacytic infiltration in the mucosa of the small bowel. Lymphomas were localized mainly in the jejunum and mesenteric nodes. The histologic subtypes were diffuse large cell in two, immunoblastic in three, and diffuse mixed in one. All patients responded poorly to chemotherapy, with a median survival duration of 10.5 months. The common presenting symptoms of the 39 non-IPSID patients included abdominal pain (90%), weight loss (31%), abdominal mass (26%), obstruction (26%), and perforation (23%). Diffuse large-cell and immunoblastic lymphomas constituted 82% of cases. Four patients had stage IE, 19 stage II 1E, and 16 stage 112E disease according to the Musshoff's criteria; 22 had bulky tumors and 19 had multiple tumors. The tumors were completely resected in 14 patients. Of 33 patients treated with combination chemotherapy, 73% achieved a complete remission. With a median follow-up duration of 90 months, there have been four relapses, with only one at the primary tumor site. The overall 5-year survival and disease-free survival rates for non-IPSID patients who were treated with chemotherapy were 59% and 54%, respectively. Intensive chemotherapy produces long-term disease-free survival in locally advanced non-IPSID PSIL.

Helicobacter pylori isolated from the domestic cat: public health implications.

Helicobacter pylori has been directly linked with active chronic gastritis, peptic ulceration, and gastric adenocarcinoma in humans. Although a substantial portion of the human population is colonized with H. pylori, the patterns of transmission of the organism remain in doubt, and reservoir hosts have not been identified. This study documents the isolation of H. pylori from domestic cats obtained from a commercial vendor. The isolation of H. pylori from these cats was confirmed by morphologic and biochemical evaluations, fatty acid analysis, and 16S rRNA sequence analysis. H. pylori was cultured from 6 cats and organisms compatible in appearance with H. pylori were observed in 15 additional cats by histologic examination. In most animals, H. pylori was present in close proximity to mucosal epithelial cells or in mucus layers of the glandular or surface epithelium. Microscopically, H. pylori-infected cat stomachs contained a mild to severe diffuse lymphoplasmacytic infiltrate with small numbers of neutrophils and eosinophils in the subglandular and gastric mucosae. Lymphoid follicles were also noted, particularly in the antrum, and often displaced glandular mucosal tissue. Thus, the domestic cat may be a potential model for H. pylori disease in humans. Also, the isolation of H. pylori from domestic cats raises the possibility that the organism may be a zoonotic pathogen, with transmission occurring from cats to humans.

Brucellosis in Free-ranging Bison (Bison bison) from Teton County, Wyoming

Brucellosis was studied opportunistically in bison (Bison bison) in the free-ranging Jackson herd of approximately 120 in Teton County, Wyoming (USA) in March 1989. Recent abortion was diagnosed in a 2-yr-old cow and Brucella abortus biovar 1 was isolated from vaginal discharge, uterine contents, uterus, and supramammary lymph nodes. Endometritis was characterized by lymphoplasmacytic infiltrates in the lamina propria and neutrophils in uterine glands and within necrotic debris and exudate in the uterine lumen. A 5-yr-old bull had diffuse lymphoplasmacytic infiltrates in epididymis and accessory sex glands; B. abortus was isolated from seminal vesicle and ampulla. Twenty-seven (77%) of 35 bison tested from 1989 to 1990 were serologically positive or suspect on tests for Brucella antibodies. We report the occurrence of abortion due to brucellosis in free-ranging bison in the Jackson herd, suggest that bison in this herd are capable of transmitting brucellosis to other susceptible hosts, and report the first confirmation of brucellosis in this herd.

Pathology and Clinical Features of Gastrointestinal Lymphoma in Saudi Arabia

The histopathology and clinical presentation of 19 cases of primary gastrointestinal lymphoma is described. Our patients are similar to others in the Middle East but have a lower incidence of diarrhoea and malabsorption. All revealed a widespread chronic inflammatory background. Four patients with primary gastric lymphoma had endoscopic biopsies from the duodenum; these biopsies were completely free from tumour but showed a moderate to severe diffuse lymphoplasmacytic infiltrate. Electron microscopy shows that tumour cells penetrate basement membranes and invade the epithelium which becomes thin and attenuated. Substances which inhibit lymphocyte tropism might be useful in preventing intestinal ulceration. The MALT concept has been found useful in classification of the tumours. Two patients with unusual mesenteric node histology are described and it is thought that the appearances may indicate a substantial capacity for differentiation in the group of tumours.

Lymphoplasmacytic sclerosing pancreatitis with cholangitis: A variant of primary sclerosing cholangitis extensively involving pancreas

Pancreatic involvement in primary sclerosing cholangitis (PSC) is an extremely rare condition, and its pathologic features are poorly documented. We report two cases of an unusual lymphoplasmacytic sclerosing inflammatory disease involving the total pancreas, common bile duct, gallbladder, and, in one patient, the lip. Two elderly men presented with waxing and waning obstructive jaundice, and exhibited radiologic and ultrasonographic findings highly suggestive of pancreatic carcinoma. Gross appearance of the pancreas showed firm and mass-like enlargement with regional lymph node swelling. Histologic findings were characterized by diffuse lymphoplasmacytic infiltration with marked interstitial fibrosis and acinar atrophy, obliterated phlebitis of the pancreatic veins, and involvement of the portal vein. Similar inflammatory processes involved the bile duct and the gallbladder. Lymphoplasmacytic sclerosing pancreatitis with cholangitis is thought to be a more appropriate term for this condition, of which a similar lesion has been previously noted in a single case of “PSC involving pancreas”. Differences in age, radiologic appearance, and the negative history of ulcerative colitis exist, but the two cases in this study could be considered as a variant of PSC extensively involving pancreas, which can readily be mistaken for pancreatic carcinoma.

Lymphadenosis benigna cutis resulting from Borrelia infection ( Borrelia lymphocytoma)

Swelling and erythema of the right pinna developed in a 7-year-old girl. Six months later a biopsy specimen showed a dense, diffuse lymphoplasmacytic infiltrate involving most of the dermis except for a thin Grenz zone. The appearance was consistent with lymphocytoma cutis. She had been bitten by a tick on the right ear in Switzerland 6 weeks before the onset of the lesion. Serologic tests by enzyme-linked immunosorbent assay for Borrelia burgdorferi, done 6 and 11 months after the bite, yielded optical density readings of 1.04 and 0.65, respectively; indirect immunofluorescence yielded titers of 1:256 and 1:128. A Borrelia-like organism was identified by a modified Steiner stain; immunohistochemistry was noncontributory. The spirochetal origin of lymphadenosis benigna cutis is briefly reviewed.

Helicobacter pylori gastric infection in gnotobiotic beagle dogs

Establishment of infection with Helicobacter pylori and gastritis in nonhuman species is currently only successful in gnotobiotic piglets. This study was designed to determine whether H. pylori will colonize the gastrointestinal tract of gnotobiotic dogs. Gnotobiotic beagle pups were derived by standard methods. Group A (five dogs) was orally challenged with 3 x 10(8) H. pylori at 7 days of age. Group B (two dogs) received only peptone water but was contact-exposed beginning on day 23 postinfection (p.i.). Necropsy was performed on dogs on day 30 p.i. H. pylori colonized the stomach of all dogs (groups A and B). Urease map analysis correlated with the microbiologic findings and indicated that the density of colonization was less than that observed in human tissue. Organisms were also recovered from the pharynx, esophagus, duodenum, and rectum of 1, 2, 2, and 1 dog, respectively. All group A and one group B dog developed serum immunoglobulin G specific for H. pylori by day 30 p.i. Gross lesions were restricted to the stomach and consisted of small (less than 1 mm) lymphoid follicles. Microscopically, there were focal to diffuse lymphoplasmacytic infiltrates with follicle formation and mild to moderate infiltration of neutrophils and eosinophils in the gastric lamina propria. With the Warthin-Starry silver stain, organisms were seen on the surface of the gastric epithelial cells, beneath the mucus layer. We conclude that H. pylori colonizes the stomachs of gnotobiotic dogs for at least 1 month and the lesions resemble those seen in humans. H. pylori is transmissible by contact from infected to noninfected dogs.

Quantiative Immunohistologic and Histomorphometric Diagnostic Criteria for Sjögren's Syndrome

Sjögren's syndrome (SS) is a chronic auto-immune exocrinopathy, especially affecting the lacrimal and salivary glands. The aim of this study is to improve the diagnostic possibilities of the sublabial salivary gland (SSG) biopsy. The SSG biopsies of 19 patients with SS and 65 healthy control subjects were used in a quantitative immunohistologic and histomorphometric study. Statistical analysis of the immunohistochemical data resulted in a diagnostic criterion, which is based on the percentages of IgA- and IgG-containing plasma cells. Statistical analysis of 3 immunohistologic and 6 histomorphometric features resulted in a combined immunohistologic and histomorphometric criterion, which is based on 2 immunohistologic parameters (the percentages IgA- and IgG-containing plasma cells) and 3 histomorphometric parameters (the volume percentages of acini, intralobular ducts and diffuse lymphoplasmacytic infiltrate). The immunohistologic diagnostic criterion has a specificity of 95.4%, a sensitivity of 100% and an overall percentage of misclassification of 3.6%. The combined diagnostic criterion has a specificity of 98.5%, a sensitivity of 100% and an overall percentages of misclassification of 1.2%. Furthermore it reduces the number of false positive diagnoses with a factor 6 from 9% to 1.5%.

Cavitation and other atypical manifestations of Pneumocystis carinii pneumonia.

In the 1980s, under the impact of the acquired immune deficiency syndrome, Pneumocystis carinii Pneumonia (PCP) has become the prime infectious manifestation of this condition. In addition to the well-recognized "classic" features of this disease, several unusual manifestations are being recognized with increasing frequency. We presently review and illustrate the following "atypical" manifestations of PCP: (1) interstitial lung responses that include diffuse alveolar damage, bronchiolitis obliterans, interstitial fibrosis, and lymphoplasmacytic infiltrates; (2) striking localized processes frequently exhibiting granulomatous features; (3) extensive necrosis and cavitation; and (4) extrapulmonary dissemination of the disease. Close clinico-pathologic correlation and attention to roentgenographic detail are invaluable aids in arriving at the correct diagnosis.

Mortality of captive tortoises due to viviparous nematodes of the genus Proatractis (Family Atractidae).

Between September 1982 and January 1984, verminous colitis was diagnosed post mortem in eight red-footed tortoises (Geochelone carbonaria) and three leopard tortoises (Geochelone pardalis) from the reptile collection of the National Zoological Park. This represented 69% of 16 tortoise necropsy accessions for that period. Etiology was determined to be a viviparous pinworm-like nematode of the genus Proatractis (Family Atractidae). Clinical signs were either nonspecific, consisting of anorexia, lethargy, and depression, or were absent. Limited trials with piperazine citrate and fenbendazole appeared to be ineffectual against the parasite and supportive therapy was unsuccessful. Post mortem examination revealed roughening and thickening of the mucosa of the cecum and colon, and in severe cases myriads of tiny (0.5-1.0 cm) nematodes were evident on the mucosal surface. In six tortoises, worms were found also in the small intestine. Histopathologic features in severe cases included mucosal necrosis with parasites and mixed inflammatory cells extending into the tunica muscularis. Focal to diffuse lymphoplasmacytic infiltrates were present consistently in the submucosa of the cecum and colon, and similar but milder lesions occasionally occurred in the small intestine.

Primary lymphomas of the small intestine: East‐west contrast

Primary small intestinal lymphoma (PSIL) represents a heterogenous group of disorders with variable clinical and pathologic features and a characteristic age, socioeconomic, and geographic distribution. In developed countries, PSIL usually occurs as a localized ileal tumor, shows a bimodal age distribution, and most frequently presents with abdominal pain and obstructive symptoms. Histologically, most of these tumors are diffuse histiocytic, lymphocytic, or undifferentiated lymphomas. Other variants of PSIL, collectively referred to as immunoproliferative small intestinal disease, occur most often among young patients of poor socioeconomic status in Third World countries, mostly in the Middle East and Mediterranean area. They are characterized by involvement of long loops of the upper small intestine and commonly present with abdominal pain, diarrhea, malabsorption, and clubbing of the fingers. A subgroup of these patients shows a serological abnormality with the appearance of part of the alpha heavy chain of IgA in the serum. Histologically, the lesion appears as a dense diffuse lymphoplasmacytic infiltrate of the mucosa of the upper jejenum or duodenum. A form of malignant lymphoma of true histiocytic origin complicates long-standing celiac disease. The contrasting clinical, epidemiological, histopathological, and immunological features of these variants of PSIL raise interesting questions about the pathogenesis of small bowel lymphoma.