Gastric and intestinal diffuse large B-cell lymphomas are clinically and immunophenotypically different. An immunohistochemical and clinical study

Gastrointestinal Tract Lymphomas: A Review of the Most Commonly Encountered Lymphomas

CONTEXT.—

The gastrointestinal (GI) tract is the most common site of extranodal non-Hodgkin lymphoma, accounting for 20% to 40% of all extranodal lymphomas. The majority of these are systemic processes secondarily involving the GI tract. Primary GI lymphomas are less common, accounting for approximately 10% to 15% of all non-Hodgkin lymphoma. Most non-Hodgkin lymphoma involving the GI tract are of B-cell lineage, of which diffuse large B-cell lymphoma is the most common subtype, irrespective of location.

OBJECTIVE.—

To review the lymphoproliferative neoplasms of B-cell and T-cell lineage involving the luminal GI tract according to the most prevalent subtypes at each anatomic site.

DATA SOURCE.—

Systematic search of the PubMed database for updated literature on GI lymphomas epidemiology, subtypes, clinical, endoscopic, and genetic findings. Histologic images are derived from our collection of clinical cases.

CONCLUSIONS.—

The GI tract is the most common site of extranodal lymphoproliferative neoplasms. Recognition of the most frequently encountered GI lymphomas is imperative for patient management and treatment.

Update on B-cell lymphoproliferative disorders of the gastrointestinal tract

The gastrointestinal (GI) tract is home to a significant portion of the immune system, which interacts daily with the antigenic milieu of its contents. Therefore, the presence of white blood cells within the walls of the GI tract upon histologic examination is a familiar sight on GI biopsies-both in health and disease. The GI tract is the most common site of extranodal lymphomas, most of which are B-cell neoplasms. Here, we review common and uncommon B-cell neoplasms of the GI tract - extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), mantle cell lymphoma, duodenal-type follicular lymphoma, diffuse large B-cell lymphoma, plasmablastic lymphoma, EBV-positive mucocutaneous ulcer, and post-transplant lymphoproliferative disorders - with special focus on literature published during the past five years. Along with the other articles in this edition of Seminars in Diagnostic Pathology, it is the authors' hope that this review proves to be a useful resource in the workup of the array of hematopoietic processes that can involve the GI tract.

Recent advances upper gastrointestinal lymphomas: molecular updates and diagnostic implications

Approximately one-third of extranodal non-Hodgkin lymphomas involve the gastrointestinal (GI) tract, with the vast majority being diagnosed in the stomach, duodenum, or proximal small intestine. A few entities, especially diffuse large B-cell lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, represent the majority of cases. In addition, there are diseases specific to or characteristic of the GI tract, and any type of systemic lymphoma can present in or disseminate to these organs. The recent advances in the genetic and molecular characterisation of lymphoid neoplasms have translated into notable changes in the classification of primary GI T-cell neoplasms and the recommended diagnostic approach to aggressive B-cell tumours. In many instances, diagnoses rely on morphology and immunophenotype, but there is an increasing need to incorporate molecular genetic markers. Moreover, it is also important to take into consideration the endoscopic and clinical presentations. This review gives an update on the most recent developments in the pathology and molecular pathology of upper GI lymphoproliferative diseases.

Clinicopathological features of 49 primary gastrointestinal diffuse large B-cell lymphoma cases; comparison with location, cell-of-origin, and frequency of MYD88 L265P

The gastrointestinal (GI) tract is the most common primary site of extranodal diffuse large B-cell lymphoma (DLBCL), with approximately one-third of extranodal DLBCL occurring in the GI tract. We investigated the clinicopathological features and immunohistochemically-assessed cell-of-origin of 49 GI DLBCL cases (stomach, 24; small intestine, 10; colon, 15) and also examined the presence of MYD88 L265P as recently this mutation has been frequently identified in ABC-like DLBCL, particularly in extranodal sites. Small intestinal DLBCL was characterized by the preponderance of women (P = 0.041) and elevated LDH (P = 0.002) and soluble interleukin-2 receptor (P = 0.033). Small intestinal DLBCL more frequently showed anemia (P = 0.031) and elevated CRP (P = 0.029) than gastric DLBCL. ABC-like phenotype was seen in 71.4 % cases (stomach, 79 %; small intestine, 70 %; colon, 60 %). MYD88 L265P was detected in 6.1 % cases; all were primary gastric DLBCL with ABC-like phenotype but had no distinct clinicopathological features. In conclusion, GI DLBCL had different clinicopathological features according to the primary site especially in the small intestine. Also, MYD88 L265P had little involvement in GI DLBCL compared with other extranodal DLBCLs, suggesting that its pathogenesis might be different from that of organs with a high frequency of MYD88 L265P.

Recent advances in intestinal lymphomas

A large variety of lymphoma types may develop as primary intestinal neoplasms in the small intestines or, less often, in the colorectum. Among these are a few entities such as enteropathy-associated T-cell lymphoma or immunoproliferative small intestinal disease that, essentially, do not arise elsewhere than in the gastrointestinal tract. In most instances the primary intestinal lymphomas belong to entities that also occur in lymph nodes or other mucosal sites, and may show some peculiar features. In the case of follicular lymphoma, important differences exist between the classical nodal cases and the intestinal cases, considered as a variant of the disease. It is likely that the local intestinal mucosal microenvironment is a determinant in influencing the pathobiological features of the disease. In this review we will present an update on the clinical, pathological and molecular features of the lymphoid neoplasms that most commonly involve the intestines, incorporating recent developments with respect to their pathobiology and classification. We will emphasize and discuss the major differential diagnostic problems encountered in practice, including the benign reactive or atypical lymphoid hyperplasias, indolent lymphoproliferative disorders of T or natural killer (NK) cells, and Epstein-Barr virus (EBV)-related lymphoproliferations.

Clinicopathologic analysis of localized nasal/paranasal diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) comprises 2 molecularly distinct subgroups of non-germinal center B-cell-like (non-GCB) and germinal center B-cell-like (GCB) DLBCLs, with the former showing relatively poor prognosis. In the present study, we analyzed the clinicopathological features of 39 patients with localized nasal/paranasal DLBCL. Immunohistochemistry-based subclassification revealed that 11 patients (28%) were of the GCB-type according to Hans’ algorithm and 11 (28%) were of the GCB-type according to Choi’s algorithm. According to both Hans’ and Choi’s algorithms, the non-GCB type was predominant. Nevertheless, prognosis was good. Overall survival did not differ significantly between the GCB and non-GCB subgroups (Hans’ algorithm: p = 0.57, Choi’s algorithm: p = 0.99). Furthermore, the prognosis of localized nasal/paranasal DLBCL was better than that of other localized extranodal DLBCLs. The prognosis of extranodal DLBCL is usually considered poorer than that of nodal DLBCL. However, in our study, no difference was noted between patients with localized nasal/paranasal DLBCL and patients with localized nodal DLBCL. In conclusion, although the non-GCB subtype is thought to show poor prognosis, in our study, the prognosis for localized nasal/paranasal DLBCL patients was good irrespective of subclassification.

Comparison of treatment strategies for patients with intestinal diffuse large B-cell lymphoma: surgical resection followed by chemotherapy versus chemotherapy alone

The aim of this retrospective cohort study was to analyze the impact of surgery on the outcomes and qualities of life (QOL) in patients with intestinal diffuse large B-cell lymphoma (DLBCL). We assessed 345 patients with either localized or disseminated intestinal DLBCL and compared them according to treatment: surgical resection followed by chemotherapy versus chemotherapy alone. In patients with localized disease (Lugano stage I/II), surgery plus chemotherapy yielded a lower relapse rate (15.3%) than did chemotherapy alone (36.8%, P < .001). The 3-year overall survival rate was 91% in the surgery plus chemotherapy group and 62% in the chemotherapy-alone group (P < .001). The predominant pattern in the chemotherapy group was local relapse (27.6%). When rituximab was used with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP), there was no improvement of the outcomes in patients treated with primary surgical resection. The QOL of patients who underwent surgery and chemotherapy was lower than chemotherapy alone, but its difference was acceptable. Multivariate analysis showed that surgical resection plus chemotherapy was an independent prognostic factor for overall survival. Surgical resection followed by chemotherapy might be an effective treatment strategy with acceptable QOL deterioration for localized intestinal DLBCL. This study was registered at www.clinicaltrials.gov as #NCT01043302.

NK-cell lineage predicts poor survival in primary intestinal NK-cell and T-cell lymphomas

Most primary intestinal natural killer (NK)-cell and T-cell lymphomas (PINKTL) in the Northern Europe are enteropathy-associated T-cell lymphomas, a complication of celiac disease, which is rare in the East. Primary intestinal NK-cell lymphoma is extremely rare and is poorly characterized. We investigated 30 cases of PINKTL from Taiwan with male: female at 2:1, median age at 55.5, 80% with jejunal/ileal involvement, 77% with perforation, 27% with multicentric tumors, and 67% at stage IE. All 7 cases tested for serum IgA anti-tissue transglutaminase were negative. Only 3 (10%) tumors showed enteropathy. Six (20%) were NK-cell lymphoma and 24 (80%) were T-cell lymphoma. The tumor cells in 21/30 (70%) cases were small to medium sized, which correlated with the coexpression of both CD8 and CD56. All tumors expressed at least 1 cytotoxic marker. All 6 NK-cell lymphomas were negative for betaF1, diffusely positive for Epstein-Barr virus-encoded mRNA (EBER), and polyclonal for T-cell receptor gene rearrangement. Five (22%) of the 24 T-cell tumors expressed betaF1, 8 (35%) of the 23 tumors were positive for EBER, and 20 (95%) of the 21 tumors were clonal for T-cell receptor. The overall 1-year survival was 36%. Univariate regression analysis showed that NK-cell lineage, multicentricity, and perforation were associated with poor prognosis. NK-cell lineage (P=0.037) was a poor prognostic factor by multivariate Cox proportional hazard regression analysis. PINKTL in Taiwan is predominantly not enteropathic with a high frequency of perforation, small to medium tumor cell size and cytotoxic phenotype. Primary intestinal NK-cell lymphoma carries a very poor prognosis, and is probably a distinct entity.

Patients with localized primary non-tonsillar oral diffuse large B-cell lymphoma exhibit favorable prognosis despite a non-germinal center B-cell-like phenotype

Diffuse large B-cell lymphomas are detected frequently in the oral cavity. Although tonsillar lymphomas have been rather well characterized, lymphomas originating from non-tonsillar regions, such as the gingiva, palate, and tongue, have not been well studied. We examined the pathology of clinical samples obtained from 21 patients with localized primary non-tonsillar oral diffuse large B-cell lymphoma. Immunohistological examination of CD10, Bcl-6, and MUM1 determined that 17 of 21 (81%) samples exhibited non-germinal center B-cell type, an increased proportion of non-germinal center B-cell type compared with previous reports in samples of tonsillar origin (P<0.05). The four remaining samples exhibited germinal center B-cell type, although one sample expressed MUM1. Follow-up clinical survival data were obtained from the 17 patients over a range from 4 to 173 months (mean 52 months). All patients were treated with chemotherapies, irradiation, or surgical resection. Sixteen patients achieved complete remission and two patients relapsed, but no patient has died of disease. Extranodal diffuse large B-cell lymphomas of non-germinal center B-cell type are generally characterized by poor prognosis, regardless of localized disease. Interestingly, our results indicate that, unlike similar lymphomas of tonsillar origin, localized primary non-tonsillar oral diffuse large B-cell lymphomas exhibit favorable prognosis, suggesting that these lymphomas may be clinicopathologically distinct.