Table 1.

Annual age-specific and sex-specific incidence rate of hepatosplenic T-cell lymphoma, per million person-years, Kaiser Permanente Northern California, 2000–2006

Men				Women			Overall
Age, years	No. of cases	Population at risk, millions	Incidence rate (95%CI)**	No. of cases	Population at risk, millions	Incidence rate million (95%CI)**	No. of cases	Population at risk, millions	Incidence rate (95%CI)**
0–9	0	1.326	—	0	1.276	—	0	2.602	—
10–19	1	1.545	0.6	0	1.493	—	1	3.038	0.3
20–29	0	1.204	—	0	1.327	—	0	2.531	—
30–39	0	1.511	—	0	1.555	—	0	3.066	—
40–49	1	1.648	0.6	1	1.740	0.6	2	3.388	0.6
50–59	2	1.408	1.4	0	1.554	—	2	2.962	0.7
60–69	1	0.866	1.2	0	0.968	—	1	1.834	0.5
70–79	0	0.547	—	0	0.668	—	0	1.214	—
Total*	5	10.055	0.4 (0.13–0.93)	1	10.581	0.1 (0.03–0.56)	6	20.635	0.3 (0.11–0.65)

^*Standardized to the US population, 2000.

^**Per million person-years.

Cases included a 19-year-old male patient with Crohn’s disease with a history of steroid for 22months, azathioprine for 65months, and infliximab for 40 months; a 42-year old female patient with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) who had a history of use of HIV/AIDS medications; and 4 men, aged 47–66years, without histories of immune-mediated disease or drug use. The case with αβ-hepatosplenic T-cell lymphoma (HSTLC) was a 47year-old man. All other cases were diagnosed with γδ-HSTCL.