Cutaneous Peripheral T-Cell Lymphoma of Cytotoxic Phenotype Mimicking Extranodal NK/T-Cell Lymphoma

Abstract

Cutaneous peripheral T-cell lymphoma unspecified is a rare neoplasm that is infrequently associated with Epstein-Barr virus (EBV) infection. In contrast, extranodal natural killer (NK)/T-cell lymphoma, although also rare, is known to be strongly associated with EBV and occurs most commonly in the nasal region. We report the case of a 55-year-old male who presented with fever and an indurated cutaneous plaque with ulceration. This cutaneous neoplasm showed diffuse dermal lymphomatous infiltration and tumor necrosis, with neoplastic cells expressing CD2, cytoplasmic CD3 (CD3ε), CD8, CD16, CD30, T-cell intracellular antigen-1, and granzyme B but not CD56, BF1, or T-cell receptor (TCR) δ1. Furthermore, the tumor cells were noted to be diffusely positive for EBV by in situ hybridization. A monoclonal TCR gene rearrangement was demonstrated. The disease showed an aggressive clinical course, and the patient died within 3 weeks of diagnosis without complete staging or chemotherapy. According to the 2005 World Health Organization/European Organization for Research and Treatment of Cancer scheme for cutaneous lymphoma and the 2008 WHO classification for lymphoid neoplasms, our case would have been classified as a nasal type extranodal NK/T-cell lymphoma with T-cell lineage. However, the expressions of CD8 and CD16, in addition to a monoclonal TCR gene rearrangement, are unusual findings in NK/T-cell lymphoma, and we believe such a phenotype/genotype should be more appropriately classified as an EBV-positive peripheral T-cell lymphoma, unspecified with a cytotoxic phenotype. Detailed clinicopathologic and molecular studies of similar cases may shed light on the prognostic impact of NK vs. T-cell lineage on extranodal NK/T-cell lymphomas.

Nasal-type NK/T-cell lymphomas are more frequently T rather than NK lineage based on T-cell receptor gene, RNA, and protein studies: lineage does not predict clinical behavior

“…1 Two recent studies have tried to distinguish EBV-positive cytotoxic T-cell lymphomas from ENKTLs based on the expression of TCR or monoclonal TCR gene rearrangements. 42,43 As shown in this study, the cellular lineage did not have a significant clinical impact for patients with an EBV-positive extranodal cytotoxic cell lymphoma. Thus-at least in clinical contexts-the term ENKTL is suitable to encompass EBV-positive extranodal cytotoxic cell lymphomas irrespective of the presence of T or NK cells in an appropriate clinical setting.…”

Peripheral T-cell lymphoma mimicking classic Hodgkin’s lymphoma in a patient presenting with fevers of unknown origin

“…Aetiologies in the literature reported to mimic PTCL include Hodgkin’s disease,10 cirrhosis and other hepatic diseases,11–13 cellulitis,14 stroke,15 ulcer,16 post-transplant lymphoproliferative disease (PTLD)17 and FUO18 (table 1). In addition, there are reports of PTCL having been diagnosed after initially mimicking alternate diagnoses, including Mycobacterium,19 EBV,20–22 natural killer lymphoma,23 tuberculosis24 and syphilis25 (table 2). With Hodgkin’s lymphoma in particular, Gaulard et al first noted the utility of combining histology and immunohistochemistry to reveal a clonal T-cell population to distinguish the aforementioned entities 26.…”

Angioinvasive Lymphomatoid Papulosis

“…26,27 The histologic findings of angiocentric and angiodestructive infiltrates of atypical lymphocytes and their cytotoxic CD8 + phenotype in most cases of LyP type E may result in interpretation of these cases as highly malignant and aggressive lymphomas. [28][29][30][31][32][33][34][35][36] With regard to the low-malignant course with the proclivity of the lesions to undergo spontaneous regression and the excellent prognosis, it is crucial to differentiate this LyP variant from primary cutaneous lymphomas with angiocentric infiltrates and/or a cytotoxic CD8 + or CD56 + phenotype. In the majority of cytotoxic CD8 + cutaneous T-cell lymphomas, the course of the disease is characterized by rapid progression with cutaneous and visceral spread and fatal outcome within months to few years.…”