Clinicopathological features of gastric B-cell lymphoma: a series of 317 cases

Clinicopathological and molecular genetic characteristics of primary gastric follicular lymphoma☆,☆☆,☆☆☆

Primary gastric follicular lymphomas (FLs) have been rarely reported and little is known about their characteristics. In the present study, we report five cases of primary gastric FL and describe their clinicopathological and molecular genetic features. A total of seven samples from five patients were investigated for clinicopathological characteristics and somatic mutations by the targeted sequencing of 50 lymphoma-related genes. Two cases were identified as slightly elevated submucosal tumors and three cases as polypoid tumors. Histologically, all cases were low-grade FLs. The immuno-profile was CD20⁺/CD10⁺/BCL2⁺ in four cases and CD20⁺/CD10⁺/BCL2^- in one case. Immunostaining pattern for CD21 was similar to that of classic FL. BCL2 rearrangement was not identified in fluorescence in situ hybridization studies in any of the five cases. NGS analysis showed mutations in genes involved in epigenetic modifications (KMT2D, ARID1A, EP300, CREBBP), NK-kB pathway (CARD11), and JAK-STAT pathway as found in classic follicular lymphoma. All cases presented with clinical I without the involvement of regional or systemic lymph nodes. Four patients were well, whereas one patient who received endoscopic mucosal resection of tumor without additional chemotherapy or radiotherapy experienced three relapses. In conclusion, primary gastric FL is characterized by a low-grade neoplasm with infrequent BCL2 rearrangement. After resection of the lesion, additional treatment such as radiation therapy or chemotherapy is required as there is a possibility of recurrence.

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.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.

Gastric follicular lymphoma: A report of 3 cases and a review of the literature

Follicular lymphoma (FL) occurs primarily in the gastrointestinal tract, with the stomach being one of the rarest sites. According to the literature, <20 cases of primary gastric FL have been reported, with the number of cases with detailed pathological descriptions being even less. The aim of the present study was to compare clinicopathological features of gastric FL with FL at alternative sites. A total of 3 cases of gastric FL were retrieved from among 3,216 cases in the databases of 4 university hospitals in South Korea: Seoul National University (SNU) Hospital, SNU Boramae Hospital, SNU Bundang Hospital (all Seoul, South Korea) and Dongtan Sacred Heart Hospital Hallym University (Dongtan, South Korea), including 2 primary cases and 1 case that was possibly secondary to nodal FL. The 2 primary gastric FL cases were incidentally detected in routine health check-ups. An endoscopy revealed a single polypoid submucosal mass and biopsies failed to confirm the diagnosis due to minimal mucosal involvement. Therefore, a partial gastrectomy was performed. The epicenters of the tumors were submucosal, with focal extension to the muscularis propria. However, 1 case exhibited an isolated FL nodule in the omentum. Histopathological examination revealed FL of grade 1–2 with a follicular pattern and with strong expression of germinal center markers and B-cell lymphoma 2 (BCL2). Rearrangement of BCL2 was not identified using fluorescence in situ hybridization studies in 2 cases. In contrast to these 2 cases, the remaining FL case was confirmed with an endoscopic biopsy. The endoscopy revealed multiple eroded polypoid lesions, and pathology revealed FL of grade 1–2 with a predominantly diffuse pattern, and with immunoglobulin heavy chain IGH/BCL2 translocation. In view of the extensive lymphadenopathy, the last case possibly presented as secondary involvement of nodal FL. It is challenging to diagnose FL in the stomach due to little mucosal involvement, as well as the unfamiliarity of the tumor due to its rarity. However, the results of the present study suggest that primary gastric FL may exhibit unique pathological features, including a predominantly follicular pattern and an absence of BCL2 rearrangement.

From the radiologic pathology archives: gastrointestinal lymphoma: radiologic and pathologic findings

Gastrointestinal (GI) lymphoma encompasses a heterogeneous group of neoplasms that have a common lymphoid origin but variable pathologic and imaging features. Extranodal marginal zone B-cell lymphoma (ENMZL) and diffuse large B-cell lymphoma (DLBCL) are the most common. ENMZL usually occurs in the stomach, where it is associated with chronic infection by Helicobacter pylori, and is typically a superficial spreading lesion that causes mucosal nodularity or ulceration and mild wall thickening. DLBCL may arise de novo or from transformation of ENMZL or other low-grade lymphomas. This form of lymphoma produces extensive wall thickening or a bulky mass, but obstruction is uncommon. Mantle cell lymphoma is the classic cause of lymphomatous polyposis, but multiple polyps or nodules can also be seen with ENMZL and follicular lymphoma. Burkitt lymphoma is usually characterized by an ileocecal mass or wall thickening in the terminal ileum in young children, often in the setting of widespread disease. Primary GI Hodgkin lymphoma, which is rare, may be manifested by a variety of findings, though stenosis is more common than with non-Hodgkin lymphoma. Enteropathy-associated T-cell lymphoma is frequently associated with celiac disease and is characterized by wall thickening, ulceration, and even perforation of the jejunum. Accurate radiologic diagnosis of GI lymphoma requires a multifactorial approach based on the clinical findings, site of involvement, imaging findings, and associated complications.

Pediatric gastric lymphoma: a rare entity

Primary gastric lymphoma is a rare event in childhood. We describe a 13-year-old boy with gastric Burkitt-like lymphoma localized in the fundus. Symptoms mimicking gastritis-epigastric pain, hypochromic anemia, anorexia, and weight loss had been present for a few months before diagnosis. No Helicobacter pylori infection was shown at diagnosis. Biopsies obtained by ultrasound gastroscopy proved the diagnosis; F-fluorodeoxyglucose-positron emission tomography detected an isolated large gastric hypermetabolic mass. According to the international FAB/LMB 96 trial, the patient was treated with chemotherapy alone and is in first complete remission 2(1/2) years after diagnosis.

Synchronous primary gastric mantle cell lymphoma and early gastric carcinoma: a case report

Mantle cell lymphoma (MCL) commonly invades the gastrointestinal (GI) tract. However, primary GI MCL is rare. We experienced a case of synchronous early gastric cancer (EGC) with primary gastric MCL found as a single early lesion rather than as multiple lymphomatous polyposis. An EGC was found in the cardia of a 64-year-old male on a routine GI endoscopic examination. A specimen obtained by total gastrectomy revealed another slightly elevated lesion in the pylorus. Microscopically, monotonous small- to medium-sized atypical lymphocytes with angulated nuclei formed a mass beneath the gastric mucosa. On immunohistochemical staining, the tumor cells revealed strong positivity for cyclin D1, positivity for both CD20 and bcl-2, and weak positivity for CD5, suggesting MCL. Clinically, there was no lymphoma in any other part of the body. This is the first case of an EGC accompanying a primary gastric MCL. Further investigation of a relationship between MCL and EGC and of factors that may affect GI involvement of MCL is necessary.

A case of primary gastric lymphoma in a child

Primary gastric lymphoma is a rare gastrointestinal cancer in children. Adult cases of primary gastric lymphoma are often associated with Helicobacter pylori infection and in the past were treated mainly by surgery with additional chemotherapy and/or radiotherapy. We experienced a case recently of a primary gastric lymphoma in a girl. She presented at our hospital with epigastric abdominal pain and upper gastrointestinal bleeding. Chemotherapy alone sufficiently controlled the disease and no additional therapeutic modalities were needed.

Lymphomatous polyposis of the gastrointestinal tract, including mantle cell lymphoma, follicular lymphoma and mucosa-associated lymphoid tissue lymphoma

AIMS

Lymphomatous polyposis (LP) is considered to represent mantle cell lymphoma (MCL) of the gastrointestinal (GI) tract. However, a few reports have suggested that some are follicular lymphoma (FL) or mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we analysed 35 patients and clarified the clinicopathological features of LP.

METHODS AND RESULTS

Paraffin-embedded tissue samples were stained immunohistochemically and analysed by tissue-fluorescence in situ hybridization (T-FISH) for IGH/CCND1 (cyclin D1) and IGH/BCL2. The average age of the patients was 58.3 years. Over half of the cases showed gastric, duodenal, small intestinal, ileocaecal and sigmoid colonic lesions (15, 19, 15, 16 and 16 cases, respectively). Phenotypically, cases were classified into three types of MCL (cyclin D1+ CD5+ CD10-) (n=12), FL (cyclin D1- CD5- CD10+) (n=14) and MALT (cyclin D1- CD5- CD10-) (n=9). T-FISH identified 11 of the 11 examined cases with MCLs to have IGH/CCND1, while seven of 10 cases with FL had IGH/BCL2, and none of the MALT cases were positive for IGH/CCND1 or IGH/BCL2. At the study endpoint, five of 12 patients with MCL were dead, two of 14 with FL and one of nine with MALT were dead of other disease. Event-free survival analysis showed significantly poorest outcome in MCL, followed by FL, while MALT was associated with a favourable outcome (P=0.0040).

CONCLUSIONS

Our study emphasizes the importance of differentiating MCL, FL and MALT of LP in evaluating prognosis and hence the most suitable therapeutic regimen.

No evidence of a correlation between BCL10 expression and API2-MALT1 gene rearrangement in ocular adnexal MALT lymphoma

In the present study, 62 cases of ocular adnexal lymphoproliferative disorders were reviewed clinicopathologically. Of them, 51 were extranodal marginal zone B-cell lymphoma (MALT lymphoma), five were diffuse large B-cell lymphoma (DLBCL), one was peripheral T-cell lymphoma, one was NK/T cell lymphoma, nasal type, and four were reactive lymphoid hyperplasia. These lymphoma cases showed a favorable clinical course and localized disease, except for the case of NK/T cell lymphoma, although 19 cases (32.8%) had a recurrence of disease. To clarify the correlation between BCL10 protein expression and API2-MALT1 gene rearrangement, the 51 cases of MALT lymphoma and 5 cases of DLBCL were analyzed by immunohistochemical and RT-PCR methods. Nuclear BCL10 expression was identified in 58% of MALT lymphoma cases, but not in any DLBCL cases. There was no evidence of a correlation between aberrant nuclear BCL10 expression and the clinical parameters examined in the present study. API2-MALT1 transcription was not demonstrated in either the MALT lymphoma cases or the DLBCL cases studied using a multiplex one-tube reverse transcriptase-PCR method. These findings indicate that the nuclear expression of BCL10 is unlikely to correlate with the API2-MALT1 fusion gene in ocular adnexal MALT lymphoma.