When a computed tomography CT scan reveals the

When a computed tomography (CT) scan reveals the presence of an infiltrative process accompanied by enlarged lymph nodes in the abdomen or pelvis, lymphoma should be the primary consideration in the differential diagnosis and must be excluded by endoscopic biopsy. Nevertheless, without the presence of enlarged lymph nodes it is difficult to distinguish this type of tumor from primary adenocarcinoma. The potential role of positron-emission tomography for the diagnosis and follow-up of patients with lymphoma has yet to be established.
Staging and management The Ann Arbor staging system, originally used for Hodgkin\'s disease, is now widely used for NHL. The extent of the disease is classified as stage I–IV according to the distribution of disease. For stage I, the disease involves a single-node region. Stage II disease involves two or more node regions on the same side of the diaphragm; the involvement of node regions on both sides of the clemastine defines stage III. Diffuse involvement of the extralymphatic organs with or without node regions is classified as stage IV. Furthermore, localized extralymphatic disease is described by the use of the subscript letter “E”. For PCL, the disease stage at the time of diagnosis varies in different publications. A 371-patient study in Germany showed that approximately 90% of the patients with GI NHL had stage IE/IIE disease. On the other hand, a 244-patient study from the USA reported that over half of the patients presented with stage IV disease. In the Taipei-VGH series, 18 (67%) patients had early-stage (stage I or II) and nine (33%) had late-stage disease. Overall, the 3- and 5-year survival rates for PCL patients were 60.8% and 47.3%, respectively. NHL types can be separated into two distinct prognostic groups: indolent and aggressive. The indolent group responds well to radiation therapy and demonstrates a good clinical prognosis when diagnosed in the early stages. The aggressive subtype of NHL generally has a less favorable prognosis and requires more intensive therapy. However, studies of the factors affecting the survival of PCL patients are inconclusive, though the stage at diagnosis, histological grade, and any complications that result in urgent surgery do have an impact on survival. Chemotherapy remains the basis of treatment for rapidly proliferating aggressive lymphomas because most NHLs present as systemic disease. The CHOP chemotherapeutic regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) remains as the first-line therapy for all moderate and high-grade B-cell lymphomas. Rituximab, a chimeric anti-CD20 monoclonal antibody, induces the death of normal and malignant B-cells Selection express the cell-surface molecule CD20. Treatment with rituximab as a single agent results in significant responses in patients with almost every subtype of B-cell lymphoma. For low-grade lymphomas, a single alkylating agent and CVP (cyclophosphamide, vincristine, and prednisone) are the preferred choice of treatment. The role of surgery is to establish a diagnosis of extranodal NHL. However, there are some controversies regarding the role of surgery for managing GI tract lymphoma. For the treatment of primary gastric DLBCL, the role of surgery has diminished and the treatment strategy has moved toward organ preservation because surgical resection is not superior to chemotherapy plus radiotherapy. However, two specific problems with intestinal DLBCL enhance the role of surgical resection for managing intestinal lymphomas: difficulties in the preoperative pathological diagnosis and the risk of intestinal perforation (Fig. 2). Because the incidence of PCL is low, there has never been a controlled randomized trial to define the role of surgery for the treatment of PCL. Some authors have suggested that systemic chemotherapy alone should be the standard treatment, with surgery reserved for complications such as perforation, obstruction, and bleeding, whereas others believe that surgery provides better localized disease control and improves the survival outcome. The results of the Taipei-VGH series suggests that for PCL patients, surgery followed by chemotherapy produces a statistically better survival rate when compared to chemotherapy alone. Recently, a large retrospective cohort study in Korea showed that for patients with localized disease (stage I/II), surgery plus chemotherapy yields a lower relapse rate (15.3%) than chemotherapy alone (36.8%). However, surgical resection did not provide any significant benefit to patients with disseminated disease. For disseminated disease, adding rituximab to CHOP (R-CHOP) resulted in a better 3-year overall survival (59%) compared with CHOP alone (29%). These data suggest that R-CHOP is a better treatment for disseminated disease. However, the addition of rituximab to CHOP failed to show additional survival benefits regardless of localized disease, regardless of surgery.