Chapter 105. Malignancies of Lymphoid Cells (Part 16)

Evaluation of patients with MALT lymphoma follows the pattern (Table 105-11) for staging a patient with non-Hodgkins lymphoma. In particular, patients with gastric lymphoma need to have studies performed to document the presence or absence of H. pylori infection. Endoscopic studies including ultrasound can help define the extent of gastric involvement. Most patients with MALT lymphoma have a good prognosis, with a 5-year survival of ~75%. In patients with a low IPI score, the 5-year survival is ~90%, while it drops to ~40% in patients with a high IPI score.Mucosa-Associated Lymphoid Tissue Lymphoma: TreatmentMALT lymphoma is often localized. Local...
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Chapter 105. Malignancies of Lymphoid Cells (Part 16) Chapter 105. Malignancies of Lymphoid Cells (Part 16) Evaluation of patients with MALT lymphoma follows the pattern (Table105-11) for staging a patient with non-Hodgkins lymphoma. In particular, patientswith gastric lymphoma need to have studies performed to document the presenceor absence of H. pylori infection. Endoscopic studies including ultrasound canhelp define the extent of gastric involvement. Most patients with MALTlymphoma have a good prognosis, with a 5-year survival of ~75%. In patients witha low IPI score, the 5-year survival is ~90%, while it drops to ~40% in patientswith a high IPI score. Mucosa-Associated Lymphoid Tissue Lymphoma: Treatment MALT lymphoma is often localized. Local therapy such as radiation orsurgery can effect cure, and this is one of the few times where surgery might be areasonable primary therapy for a patient with non-Hodgkins lymphoma. Patientswith gastric MALT lymphomas who are infected with H. pylori can achieveremission in the majority of cases with eradication of the infection. Theseremissions can be durable, but molecular evidence of persisting neoplasia isfrequent and the long-term outcome is uncertain. Patients who present with moreextensive disease are most often treated with single-agent chemotherapy such aschlorambucil. Data on combination regimens that include rituximab are beinggenerated, but its efficacy in other B cell tumors and low toxicity support its use.Coexistent diffuse large B cell lymphoma must be treated with combinationchemotherapy (see below). The additional acquired mutations that mediate thehistologic progression also convey Helicobacter independence to the growth. Mantle Cell Lymphoma Mantle cell lymphoma makes up ~6% of all non-Hodgkins lymphomas.This lymphoma was previously placed in a number of other subtypes. Its existencewas confirmed by the recognition that these lymphomas have a characteristicchromosomal translocation, t(11;14), between the immunoglobulin heavy chaingene on chromosome 14 and the bcl-1 gene on chromosome 11, and regularlyoverexpress the BCL-1 protein, also known as cyclin D1. Table 105-10 shows theclinical characteristics of mantle cell lymphoma. The diagnosis of mantle cell lymphoma can be made accurately by anexpert hematopathologist. As with all subtypes of lymphoma, an adequate biopsyis important. The differential diagnosis of mantle cell lymphoma includes othersmall cell B cell lymphomas. In particular, mantle cell lymphoma and smalllymphocytic lymphoma share a characteristic expression of CD5. Mantle celllymphoma usually has a slightly indented nucleus. The most common presentation of mantle cell lymphoma is with palpablelymphadenopathy, frequently accompanied by systemic symptoms. Approximately70% of patients will be stage IV at the time of diagnosis, with frequent bonemarrow and peripheral blood involvement. Of the extranodal organs that can beinvolved, gastrointestinal involvement is particularly important to recognize.Patients who present with lymphomatosis polyposis in the large intestine usuallyhave mantle cell lymphoma. Table 105-11 outlines the evaluation of patients withmantle cell lymphoma. Patients who present with gastrointestinal tractinvolvement often have Waldeyers ring involvement, and vice versa. The 5-yearsurvival for all patients with mantle cell lymphoma is ~25%, with only occasionalpatients who present with a high IPI score surviving 5 years and ~50% of patientswith a low IPI score surviving 5 years. Mantle Cell Lymphoma: Treatment Current therapies for mantle cell lymphoma are unsatisfactory. Patientswith localized disease might be treated with combination chemotherapy followedby radiotherapy; however, these patients are exceedingly rare. For the usualpresentation with disseminated disease, treatments have been unsatisfactory, withthe minority of patients achieving complete remission. Aggressive combinationchemotherapy regimens followed by autologous or allogeneic bone marrowtransplantation are frequently offered to younger patients. For the occasionalelderly, asymptomatic patient, observation followed by single-agent chemotherapymight be the most practical approach. An intensive combination chemotherapyregimen originally used in the treatment of acute leukemia, HyperC-VAD(cyclophosphamide, vincristine, doxorubicin, dexamethasone, cytarabine, andmethotrexate), in combination with rituximab seems to be associated with betterresponse rates—particularly in younger patients. CHOP plus rituximab has shownbetter response rates than CHOP alone, but long-term follow-up is lacking.Bortezomib induces transient partial responses in a minority of patients. ...