Primary Gastric Lymphoma-A Case Report

Primary gastric lymphoma accounts for less than 5% of gastric cancers. They are usually non-Hodgkin’slymphomas (NHL), but have been considered as a separate entity from NHLs of peripheral nodes. The diagnosis of primary lymphoma of stomach requires histological confirmation without any evidence of peripheral lymphadenopathy or organomegaly. Secondary gastric lymphoma indicates the involvement of the stomach by a diffuse lymphoma developed elsewhere. Here we report a 50 year old male presented with abdominal pain and intermittent vomiting and diagnosed as primary gastric lymphoma.

On investigation, Complete Blood Count with peripheral blood film was unremarkable, ESR was 22mm at 1 st hour, CXR PA view was normal.12lead ECG, S. Electrolyte, S. creatinine, S. lipasewere also normal.S. bilirubin, SGPT, S.Albumin, Prothrombin Time were within normal range.S. LDH was 391 U/L.Endoscopy revealedulcero proliferative, fungating growth at the distal body and antral part of stomach with nodular surfaceand areas of necrosis which bled on touch and biopsy was taken from the affected areas and was sent for histopathology.

Discussion:
Non-Hodgkin lymphoma (NHL) is a collective term for a heterogeneous group of lymphoproliferative malignancies with differing patterns of behavior and responses to treatment. 1 The gastrointestinal (GI) tract is the predominant site of extra nodal NHLs.Several reports have shown that about 5-7% of all gastric malignancies are primary malignant lymphomas 2 .It consistsabout 20% in the small bowel and 0.4% in the large gut of all the malignancies of the respective site 3 .The most common site of extranodal lymphoma is the stomach 4 .But compared with carcinoma incidence, NHL is rare, representing 2% to 8% of all gastric malignancies.Most of the NHLs (80-90%) are of B cell origin.According to Dawson et al 7 , gastric lymphomas are defined as primary when the stomach is involved primarily and if associated intra abdominal lymphadenopathy present, it corresponds to the expected lymphatic drainage of the stomach.There will be no palpable subcutaneous nodes, mediastinal nodes and organomegaly as well as no abnormal leucocytes on peripheral blood film or bone marrow aspirate.Most patients are usually in their sixth decade. 8Males are more affected and it is more common in white population. 9e most common complaints are epigastric pain, weight loss, nausea and vomiting.Occasionally a palpable abdominal mass is found.Night sweats and subcutaneous nodes are rare.Features of obstruction, bleeding and perforation are uncommon.Usually the features donot differ much from that of gastric carcinoma. 10egarding investigations, complete blood count with peripheral blood film, chest radiographs and bone marrow aspirates should be done to rule out metastasis.The diagnosis is usually made on endoscopic biopsy.The common findings are a diffuse infiltrative process, superficial ulceration or polypoidal mass protruding into the lumen. 11CT scan of abdomen can figure out the extent of the lesion and metastasis; but it cannot differentiate metastatic lymphadenopathy from reactive hyperplasia. 10ndoscopic ultrasound is fairly accurate in detecting the presence of perigastric lymphadenopathy and depth of invasion. 12Immunohistrochemistryand flow cytometryof the biopsied material should be performed to confirm the diagnosis and for accurate sub typing.Ann Arbor staging system is not optimal to stage primary GI lymphomas, now Paris staging system is used widely for this type of malignancies 13 .
As an association of gastric lymphomas with antigenic stimulation by chronic Helicobacter pylori gastritis has been found, so the current standard treatment for early stage disease is antibiotic therapy to eradicate the infection.
Though surgical resection remains the primary treatment, with the improvement t in antineoplastic regimens specially in the treatment of NHL's, now-a-days multimodality therapy of neoadjuvent chemotherapy and stomach preservation has become more popular. 14,15CHOP regimen alone (Cyclophosphamide, doxorubicin, vincristine, prednisolone) or with addition of some newer drugs like rituximab (R-CHOP) have shown promising result in the treatment of primary gastric lymphoma. 16Chemotherapy is also preferredin widespread disease.Radiotherapy is the choice when the tumor is incompletely excised. 15e histologic subtype and grade of lymphoma can have a significant impact on prognosis.Five year survival rate for low grade stage IE & IIE disease ranges from 80-90%; whereas high grade of such lymphomas ranges 39-74%.The spread of the disease to serous layer of the stomach and intra abdominal lymph nodesalso indicate poor prognosis 17 .

Fig.- 1 :
Fig.-1: Diffuse large B-cell non-Hodgkin lymphoma.Large cells with abundant cytoplasm and large round-ovoid nuclei with thick nuclear membrane and multiple prominent nucleoli.