Longo, DL. Chapter 110. Malingnancies of Lymphoid Cells. In: Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson JL, Loscalzo J, eds. Harrison’s Principles of Internal Medicine. 18th ed. New York: McGraw-Hill; 2012.
Peripheral T Cell Lymphoma
The peripheral T cell lymphomas make up a heterogeneous morphologic group of aggressive neoplasms that share a mature T cell immunophenotype. They represent ∼7% of all cases of non-Hodgkin’s lymphoma. A number of distinct clinical syndromes are included in this group of disorders. Table 110–10 shows the clinical characteristics of patients with peripheral T cell lymphoma.
The diagnosis of peripheral T cell lymphoma, or any of its specific subtypes, requires an expert hematopathologist, an adequate biopsy, and immunophenotyping. Most peripheral T cell lymphomas are CD4+, but a few will be CD8+, both CD4+ and CD8+, or have an NK cell immunophenotype. No characteristic genetic abnormalities have yet been identified, but translocations involving the T cell antigen receptor genes on chromosomes 7 or 14 may be detected. The differential diagnosis of patients suspected of having peripheral T cell lymphoma includes reactive T cell infiltrative processes. In some cases, demonstration of a monoclonal T cell population using T cell receptor gene rearrangement studies will be required to make a diagnosis.
The initial evaluation of a patient with a peripheral T cell lymphoma should include the studies in Table 110–11 for staging patients with non-Hodgkin’s lymphoma. Unfortunately, patients with peripheral T cell lymphoma usually present with adverse prognostic factors, with >80% of patients having an IPI score ≥2 and >30% having an IPI score ≥4. As this would predict, peripheral T cell lymphomas are associated with a poor outcome, and only 25% of the patients survive 5 years after diagnosis. Treatment regimens are the same as those used for diffuse large B cell lymphoma (omitting rituximab), but patients with peripheral T cell lymphoma have a poorer response to treatment. Because of this poor treatment outcome, hematopoietic stem cell transplantation is often considered early in the care of young patients.
A number of specific clinical syndromes are seen in the peripheral T cell lymphomas. Angioimmunoblastic T cell lymphoma is one of the more common subtypes, making up ∼20% of T cell lymphomas. These patients typically present with generalized lymphadenopathy, fever, weight loss, skin rash, and polyclonal hypergammaglobulinemia. In some cases, it is difficult to separate patients with a reactive disorder from those with true lymphoma.
Extranodal T/NK cell lymphoma of nasal type has also been called angiocentric lymphoma and was previously termed lethal midline granuloma. This disorder is more frequent in Asia and South America than in the United States and Europe. EBV is thought to play an etiologic role. Although most frequent in the upper airway, it can involve other organs. The course is aggressive, and patients frequently have the hemophagocytic syndrome. When marrow and blood involvement occur, distinction between this disease and leukemia might be difficult. Some patients will respond to aggressive combination chemotherapy regimens, but the overall outlook is poor.
Enteropathy-type intestinal T cell lymphoma is a rare disorder that occurs in patients with untreated gluten-sensitive enteropathy. Patients are frequently wasted and sometimes present with intestinal perforation. The prognosis is poor. Hepatosplenic γδ T cell lymphoma is a systemic illness that presents with sinusoidal infiltration of the liver, spleen, and bone marrow by malignant T cells. Tumor masses generally do not occur. The disease is associated with systemic symptoms and is often difficult to diagnose. Treatment outcome is poor. Subcutaneous panniculitis-like T cell lymphoma is a rare disorder that is often confused with panniculitis. Patients present with multiple subcutaneous nodules, which progress and can ulcerate. Hemophagocytic syndrome is common. Response to therapy is poor. The development of the hemophagocytic syndrome (profound anemia, ingestion of erythrocytes by monocytes and macrophages) in the course of any peripheral T cell lymphoma is generally associated with a fatal outcome.
Harrison’s Principles of Internal Medicine, 18e > Chapter 110. Malignancies of Lymphoid Cells
|Table 110–10 Clinical Characteristics of Patients with Common Types of Non-Hodgkin’s Lymphomas (NHL) Disease
||Median Age, years
||Frequency in Children
||Stage I/II vs III/IV, %
||B Symptoms, %
||Bone Marrow Involvement, %
||Gastrointestinal Tract Involvement, %
||% Surviving 5 years
|B cell chronic lymphocyticleukemia/small lymphocytic lymphoma
||9 vs 91
|Mantle cell lymphoma
||20 vs 80
|Extranodal marginal zone B cell lymphoma of MALT type
||67 vs 33
||33 vs 67
|Diffuse large B cell lymphoma
||~25% of childhood NHL
||54 vs 46
||~30% of childhood NHL
||62 vs 38
|Precursor T cell lymphoblastic lymphoma
||~40% of childhood NHL
||11 vs 89
|Anaplastic large T/null cell lymphoma
||51 vs 49
|Peripheral T cell non-Hodgkin’s lymphoma
||~5% of childhood NHL
||20 vs 80
Abbreviation: MALT, mucosa-associated lymphoid tissue.
Table 110-11 Staging Evaluation for Non-Hodgkin’s Lymphoma
Documentation of B symptoms
Complete blood counts
Liver function tests
Serum protein electrophoresis
CT scan of abdomen, pelvis, and usually chest
Bone marrow biopsy
Lumbar puncture in lymphoblastic, Burkitt’s, and diffuse large B cell lymphoma with positive marrow biopsy
Gallium scan (SPECT) or PET scan in large cell lymphoma
Abbreviations: PET, positron emission tomography; SPECT, single photon emission CT.