[1511] NK/T Cell Lymphomas: A Report of 72 Cases from India

Tanuja Shet, Pallavi Suryawanshi, Manju Sengar, Hari Menon, Siddharatha Laskar. Tata Memorial Hospital, Mumbai, Maharashtra, India

Background: NK/T cell lymphomas are a genre of lymphomas that show unique global geographic distribution. There is no report of the incidence and pattern of this disease from India. This series is part of a retrospective review of T cell neoplasm's in a cancer referral hospital in India.
Design: A total of 72 NK/T cell lymphomas were retrieved from a series of 242 T cell lymphomas at nodal and extranodal locations accessioned at our institute over the period from 2003 to 2010. For a diagnosis of NK/T cell lymphoma EBER positivity and cytotoxic granule expression was essential. 25 cases were misdiagnosed in intial biopsy.
Results: Fifty three patients had a nasal and 15 patients had an extranasal site that was biopsied for a diagnosis. The extranasal sites included cervix (1), gingival (1), orbit (1), liver (1), cervical nodes (7), maxillary sinus (2), tonsil (1) and soft tissue (1). All patients with extranasal sites had concurrent occult nasal involvement which in 7 was not PET scan avid and hence missed. Though typical histologic features were seen in three fourth cases, in remaining deviations were observed. Total lack of necrosis was seen in 7 cases and CD56 was absent in 9 cases. The cell size in three patients was small. EBER-ISH was done on marrow in 34 in house cases and was positive in 5 patients including 2 with obvious marrow involvement Follow up information was available in 48 patients and 24 died due to disease progression. Ann arbor stage, performance score, type of chemotherapy, marrow involvement as per EBER-ISH significantly impacted overall survival in the Kaplan Meier analysis. Only one patient of the 9 patients on SMILE (L asparaginase) therapy relapsed.
Conclusions: NK/T cell lymphomas are nor rare in India though bias of referral institute does exist in this study. Most patients with extranasal sites should have a nasal endoscopy for concurrent nasal involvement. Pathologist need to be aware of morphologic deviations as prompt therapy in early stages with SMILE regimen has resulted in improved outcome in patients.
Category: Hematopathology

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 273, Tuesday Afternoon


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