The clinicopathological features of extranodal Nk/T-cell lymphoma nasal type (NKTCL) in universitas indonesia/cipto mangunkusumo hospital jakarta

Background: Extranodal NK/T-cell lymphoma nasal type (NKTCL) is more common in Asia than in the Western countries. Classic morphological features of NKTCL include necrosis, angiocentricity and polymorphism. In small biopsy sample, these features are not always found, meanwhile there is no data regarding percentage of these features. Aims: To identify the demographic profiles of our NKTCL cases, its morphological and immunohistochemistry (IHC) features and EBV positivity. Methods: NKTCL cases during period of January 2010 to July 2014 were retrieved from our database. Data of age, sex, tumor location and initial diagnosis were recorded. Hematoxylin and eosin (HE), IHC, and EBER ISH slides were reviewed. Results: Thirty seven cases were found increasing within years, showing male predominance (M:F=2:1) ranging from 18 to 67 years old with mean age of 43. Nasal region (75.7%) was the most affected sites, meanwhile skin and soft tissue (13.5%), nasopharyngeal (5.4%), intestinal (5.4%) were the most common extranasal sites involved. Percentages of histopathological features found consecutively were: atypical cells (100%), necrosis (91.9%), angiocentricity (70.3%), polymorphism (64.9%), monomorphism (27%), but none of granuloma (0%) was found. Percentage of IHC positivity were 100% for granzyme B (35/35) and perforin (34/34), 97.3% (36/37) for CD3, 94.6% (35/37) for CD56, 94.4% (17/18) for CD16. EBER was positive in 83.3% (20/24) of cases. Conclusion: Pathologists should always be cautious of NKTCL in the presence of atypical cells found in nasal biopsy regardless of the classic histopathological features. In our center, CD16 positivity was relatively high with lower EBER positivity.