Report of the Workshop on Nasal and Related Extranodal Angiocentric T/Natural Killer Cell Lymphomas

Abstract

A workshop jointly sponsored by the University of Hong Kong and the Society for Hematopathology explored the definition, differential diagnosis, and epidemiology of angiocentric lymphomas presenting in the nose and other extranodal sites. The participants concluded that nasal T/natural killer (NK) cell lymphoma is a distinct clinicopathologic entity highly associated with Epstein-Barr virus (EBV). In situ hybridization for EBV an be very valuable in early diagnosis, especially if tissue is sparse. The cytologic spectrum is broad, ranging from small or medium-sized cells to large transformed cells. Histologic progression often occurs with time. Necrosis is nearly always present, and angioinvasion by tumor cells is seen in most cases. Nasal T/NK cell lymphoma has a characteristic immunophenotype: CD2-positive, CD56-positive, but usually negative for surface CD3. Cytoplasmic CD3 can be detected in paraffin sections. Clonal T-cell receptor gene rearrangement is not found. Tumors with an identical phenotype and genotype occur in other extranodal sites, most commonly in the skin, subcutis, and gastrointestinal tract, and should be referred to as nasal-type T/NK cell lymphomas. The differential diagnosis includes lymphomatoid granulomatosis, blastic or monomorphic NK cell lymphoma/leukemia, CD56-positive peripheral T-cell lymphoma, and enteropathy-associated T-cell lymphoma.

Nasal-type extranodal natural killer/T-cell lymphomas: a clinicopathologic and genotypic study of 42 cases in Singapore

“…However, a minority of these tumors with indistinguishable clinical, histologic and immunophenotypic features may express a T-cell phenotype and show monoclonal T-cell receptor gene rearrangement. 1,2,6,19 A recent study described the presence of restricted killer immunoglobulin-like receptor repertoire and monoclonal T-cell receptor gene rearrangement in six out of 15 cases of sinonasal lymphomas, suggesting a mixed NK/T-cell differentiation in a subset of these tumors. 32 The cell lineage of NK/TCL has been evaluated in several studies using molecular genetic techniques.…”

“…The prototype, extranodal nasal-type NK-cell lymphomas, has been well described in the last few years. [1][2][3] These lymphomas are postulated to originate from activated NK cells. 4 However, rare cases with identical clinical, histologic and immunohistochemical features may be of true T-cell derivation.…”

The latency pattern of Epstein–Barr virus infection and viral IL-10 expression in cutaneous natural killer/T-cell lymphomas

“…Several lines of evidence have shown the association of latent Epstein-Barr virus (EBV) infection with the nasal-type, extranodal natural killer or T (NK/T)-cell lymphoma which occurs predominantly in Asia and Mexico (Harabuchi et al, 1990;Su et al, 1991;Jaffe et al, 1996;Harris et al, 1999). This type of lymphoma primarily affects the nasal cavity and skin, exhibiting histopathological features of angiodestructive infiltration and tissue necrosis (Su and Hsieh, 1992;Jaffe et al, 1996;Chan et al, 1997;Iwatsuki et al, 1997), and a frequent complication of haemophagocytic syndrome (Jaffe et al, 1983(Jaffe et al, , 1996.…”

“…This type of lymphoma primarily affects the nasal cavity and skin, exhibiting histopathological features of angiodestructive infiltration and tissue necrosis (Su and Hsieh, 1992;Jaffe et al, 1996;Chan et al, 1997;Iwatsuki et al, 1997), and a frequent complication of haemophagocytic syndrome (Jaffe et al, 1983(Jaffe et al, , 1996. In addition to the presence of EBV-DNA, EBV-encoded nuclear RNA (EBER) is usually present in the neoplastic cells.…”

Ocular involvement in nasal natural killer T-cell lymphoma

“…Furthermore, lymphomas expressing NK-cell markers are known to have a highly aggressive behavior and a poorer prognosis than B-cell lymphoma or T-cell lymphoma [10][11][12]. We present the clinical, morphologic, immunohistochemical, and molecular features of a case of paranasal NKTL with ocular involvement.…”