A Case of Sinonasal Extranodal NK/T-Cell Lymphoma with Indolent Behaviour and Low-Grade Morphology


Extranodal NK/T-cell lymphoma, nasal type (ENKL), is an uncommon subtype of EBV associated lymphoma usually characterized by aggressive clinical course. We report an atypical sinonasal ENKL case with long-lasting indolent behaviour, developed in the setting of a polymorphic EBV-associated lymphoproliferative disorder (LPD). A 52-year-old woman had suffered from chronic sinusitis and nasal obstruction since 2000, moderately worsened during the last years (marked enlargement of the sino-nasal mucosa at MRI in 2011) with elevated anti-VCA IgG and IgM titers. Three subsequent biopsies revealed slightly increasing morphophenotypic atypia, ranging from a polymorphic B- and T-cell EBV positive proliferation (diagnosed in 2011, but not fulfilling CAEBV diagnostic criteria) to an overt monomorphic mildly atypical T LPD without necrosis and angiocentricty diagnosed as ENKL in 2013 upon immunophenotype and TCR-γ gene clonal rearrangement. Clinically indolent ENKL with low-grade morphology is extremely rare and diagnostically challenging; while the few reports in the literature describe long-survival in ENKL treated patients comparing histologically neoplastic lesions at onset and recurrences, no reports are published on the slow progression from a polymorphic EBV-related T/NK proliferation to a histologically overt clinically indolent ENKL in an untreated patient who only received occasional steroid administration.

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Tabanelli, V. , Valli, R. , Zanelli, M. , Righi, S. , Gazzola, A. , Mannu, C. , Pileri, S. and Sabattini, E. (2014) A Case of Sinonasal Extranodal NK/T-Cell Lymphoma with Indolent Behaviour and Low-Grade Morphology. Case Reports in Clinical Medicine, 3, 596-600. doi: 10.4236/crcm.2014.311129.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Swerdlow, S.H., Campo, E., Harris, N.L., Jaffe, E.S., Pileri, S.A., Stein, H., et al., Eds. (2008) WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. IARC Press, Lyon.
[2] Hasserjian, R.P. and Harris, N.L. (2007) A Spectrum of Tumors with Variable Manifestations and Immunophenotype. American Journal of Clinical Pathology, 127, 860-868.
[3] Chim, C.S., Ma, S.Y., Au, W.Y., Choy, C., Lie, A.K.W., Liang, R., et al. (2004) Primary Nasal Natural Killer Cell Lymphoma: Long-Term Treatment Outcome and Relationship with the International Prognostic Index. Blood, 103, 216-221.
[4] Suzuki, R., Suzumiya, J., Yamaguchi, M., et al. (2010) Prognostic Factors for Mature Natural Killer (NK) Cell Neoplasms: Aggressive NK Cell Leukemia and Extranodal NK Cell Lymphoma, Nasal Type. Annals of Oncology, 21, 1032-1040.
[5] Huang, H., Lin, Z., Lin, X., et al. (2011) Long-Term Outcomes of Patients with Newly Diagnosed Extranodal Natural Killer/T-Cell Lymphoma Treated by Etoposide, Prednisone, Vincristine, Cyclophosphamide, and Doxorubicin Regimen: A Single-Institution Experience. Leuk Lymphoma, 52, 1041-1048.
[6] Hsieh, P.P., Tung, C.L., Chan, A.B.W., et al. (2007) EBV Viral Load in Tumour Tissue Is an Important Prognostic Indicator for Nasal NK/T-Cell Lymphoma. American Journal of Clinical Pathology, 128, 579-584.
[7] Choi, Y.L., Park, J.H., Namkung, J.H., et al. (2009) Extranodal NK/T Cell Lymphoma with Cutaneous Involvement: “Nasal” vs. “Nasal-Type” Subgroups: A Retrospective Study of 18 Patients. British Journal of Dermatology, 160, 333-337.
[8] Watabe, D., Kanno, H., Inoue-Narita, T., Onodera, H., Izumida, W., Kowata, S., et al. (2009) A Case Of Primary Cutaneous Natural Killer/T-Cell Lymphoma, Nasal Type, With Indolent Clinical Course: Monoclonal Expansion Of Epstein-Barr Virus Genome Correlating with the Terminal Aggressive Behaviour. British Journal of Dermatology, 160, 205-207.
[9] Zuriel, D., Fink-Puches, R. and Cerroni, L. (2012) A Case of Primary Cutaneous Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type, with a 22-Year Indolent Clinical Course. The American Journal of Dermatopathology, 34, 194-197.
[10] Kim, S.J., Park, Y., Kim, B.S., Kim, I., Ko, Y.H., Kim, W.S., et al. (2012) Extranodal Natural Killer/T-Cell Lymphoma with Long-Term Survival and Repeated Relapses: Does It Indicate the Presence of Indolent Subtype? The Korean Journal of Hematology, 47, 202-206.
[11] Au, W.Y., Kim, S.J., Yiu, H.H., Ngan, R.K., Loong, F., Kim, W.S., et al. (2010) Clinicopathological Features and Outcome of Late Relapses of Natural Killer Cell Lymphomas 10-29 Years after Initial Remission. American Journal of Hematology, 85, 362-363.
[12] Schrader, C., Janssen, D., Kneba, M. and Lennert, K. (2004) A 38-Year History of Natural-Killer-Cell Lymphoma. The New England Journal of Medicine, 350, 418-419.
[13] Ohshima, K., Kimura, H., Yoshino, T., Kim, C.W., Ko, Y.H., Lee, S.S., et al., CAEBV Study Group (2008) Proposed Categorization of Pathological States of EBV-Associated T/Natural Killer-Cell Lymphoproliferative Disorder (LPD) in Children and Young Adults: Overlap with Chronic Active EBV Infection and Infantile Fulminant EBV T-LPD. Pathology International, 58, 209-217.

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