Aggressive mature natural killer cell neoplasms: from epidemiology todiagnosis

Table 2 Frequencies of NK/T-cell Lymphoma, nasal type, and aggressive NK-cellleukemia in previous published series

Series	Origin	NKTCL	ANKCL	NKTCL + ANKCL	[References]
NK-cell Tumor Study Group *	Asia (Japan)	150 (87.2%)	22 (12.8%)	172 (100%)	[37]
		Nasal: 123 (82.0%)
		Extranasal: 27 (18.0%)
International Peripheral T-Cell Lymphoma Project (IPTCLP)group**	North America, Europe, and Asia	127 (98.5%)	2 (1.5%)	129 (100%)	[35]
		Nasal: 92 (72.4%)
		Extranasal: 35 (27.6%)
Brazilian group	South America (Brazil)	120 (100%)	0 (0%)	120 (100%)	[44]
		Nasal: 97 (80.8%)
		Extranasal: 23 (19.2%)
Intergruppo Italiano Linfomi	Europe (Italy)	26 (100%)	0 (0%)	26 (100%)	[39]
		Nasal: 23 (88.5%)
		Extranasal: 3 (11.5%)
All series		423 (94.6%)	25 (5.6%)	447 (100%)	NA
All series		Nasal: 335 (79.4%)	25 (5.6%)	447 (100%)	NA
		Extranasal: 88 (20.6%)

Abbreviations: ANKTCL aggressive NK-cell leukemia,NKTCL NK/T-cell Lymphoma, nasal type, NA notapplicable.
* Most of the cases presented in this series were from the Japanesesurvey of NK-cell neoplasms diagnosed between 1994 and 1998, inwhich 237 cases were registered: 149 nasal-type NK-cell lymphoma(123 nasal and 26 extranasal), 22 aggressive NK-cellleukemia/lymphoma, 19 chronic NK lymphocytosis and 57 casescorresponding to diseases that are not considered as originatingfrom mature NK-cells accordingly to the WHO classification updatedin 2008 (11 myeloid/NK-cell precursor acute leukemia, 15 blasticNK-cell lymphoma, 21 precursor NK-cell acute lymphoblastic leukemia) [36].
** Consecutive cases of peripheral T-cell lymphoma (excluding MycosisFungoides and Sezary syndrome) and NK/T-cell lymphoma diagnosedbetween 1990 and 2002. Total number of cases registered: 1153 (Asia:464, 40.2%; Europe and North America 689, 59.8%). Totalnumber of NK-cell neoplasms registered: 136 (11.8%) (Asia: 104,76.5%; Europe and North America: 32, 23.5%) (NKTCL: 127;ANKCL: 2; unclassified NK-cell neoplasms: 7).

ISSN: 1750-1172