Natural killer-like T-cell lymphomas: aggressive lymphomas of T-large granular lymphocytes [see comments]

Abstract

Natural killer (NK)-like T cells are major histocompatibility complex- unrestricted cytotoxic T cells that are surface CD3-positive, express NK-cell antigens, and rearrange their T-cell receptor. Most neoplasms arising from this T-cell subpopulation have been a chronic lymphoproliferative disease referred to as T-large granular lymphocyte (LGL) leukemia. Only 10 NK-like T-cell lymphomas have been described in detail previously; this study presents the clinicopathologic features of six others and distinguishes these lymphomas from T-LGL leukemia. All patients presented with B-symptoms and often had marked hepatosplenomegaly without significant peripheral lymphadenopathy. Four of the six patients were immunosuppressed. All had CD3, CD8, CD56- positive tumors, presumably of hepatosplenic (n = 3), intestinal (n = 1), pulmonary (n = 1), or nodal (n = 1) origin. Three patients had lymphomatous bone marrow infiltrates, and four had peripheral blood involvement by neoplastic large lymphocytes, some of which had a blastic appearance or resembled virocytes. Azurophilic granules, ultrastructurally corresponding to cytoplasmic dense core and/or double density granules, were seen in all cases. T-cell clonality was shown in five tumors by Southern blot analysis, and three had abnormal karyotypes. Two untreated patients died 20 days after presentation, and three patients who received combination chemotherapy died within 5 months of presentation. One patient remains in complete remission 22 months after treatment. These findings suggest NK-like T-cell lymphomas are aggressive, are clinicopathologically distinct from T-LGL leukemia, and should be in the differential diagnosis of extranodal T-cell lymphoproliferations, including those in immunosuppressed patients. Furthermore, the LGL morphology, phenotype, and tissue distribution of some NK-like T-cell lymphomas suggest they arise from thymic- independent T cells of the hepatic sinusoids and intestinal mucosa.

Fatal subcutaneous panniculitis‐like T‐cell lymphoma with interface change and dermal mucin, a dead ringer for lupus erythematosus

“…Several studies have linked CD56 expression in lymphomas with aggressive behavior. 17 Although some benign dermatoses may have CD56 þ lymphocytes, the population is not more than 9%. 18 In our case, the CD56 þ cells were at least 20% in the skin and were over 70% in the lung, which would be most unusual for a benign process.…”

Cutaneous presentation of nasal/nasal type T/NK cell lymphoma: clinicopathological findings of four cases

“…Recently, Emile et al 18 gave support to the concept that 'nasal and nasal-type T/NK cell lymphoma' is a distinct entity and provided further evidence for a derivation from NK cells, rather than from T cells. Macon et al 19 described six cases of lymphoma that they propose are derived from a unique subset of T cells, the NK-like or NK1þ T cells. These cells reveal many of the same functions as NK cells, but are phenotypically and genotypically true T cells.…”

T-Cell Large Granular Lymphocyte Leukemia and Related Disorders

“…Most of the lymphoproliferative disorders that occur following transplantation of both solid organs and hematopoietic stem cells are B-cell malignancies associated with Epstein-Barr virus (EBV) infection. Of the T-cell lymphoproliferative disorders reported, the majority of studies describes an aggressive NK-like malignancy, in which most patients die from the lymphoma within a few months, despite withdrawal of immunosuppressive therapy and combination chemotherapy [76,77]. However, classic, indolent LGL leukemia has been described following renal [78] and liver transplantations [79].…”