Incidence of enteropathy--associated T-cell lymphoma: a nation-wide study of a population-based registry in The Netherlands.

OBJECTIVE: Enteropathy-associated T-cell lymphomas (EATLs) are T-cell non-Hodgkin lymphomas of the small bowel, which are specifically associated with coeliac disease (CD). To our knowledge no studies have previously reported on the overall incidence of EATLs in the general population. The aim of this study was to investigate the incidence of EATL and the demographic characteristics of patients with EATL in The Netherlands. MATERIAL AND METHODS: A survey of the nation-wide network and registry of histo- and cytopathology reports in The Netherlands (PALGA) was performed. We included all T-cell lymphomas detected between January 2000 and December 2006 that initially presented in the small bowel. Crude and world standardized incidence rates were computed as well as gender- and age-specific incidence rates. Finally, the distribution of characteristics such as the localization, the Marsh classification and method of diagnosis are described. RESULTS: Clinicopathological data were gathered for 116 cases of EATL. The mean age at primary presentation of EATL was 64 years. The crude incidence in the total Dutch population was 0.10/100,000 with an incidence of 2.08/100,000 in the over 50-year-olds. Age-specific incidences were 1.44/100,000 in the 50-59 years age group, 2.92/100,000 in the 60-69 years age group, and 2.53/100,000 in the 70-79 years age group. There was a significant predominance of males (64%, p=0.004, CI 54-72); above the age of 50 the gender-specific incidence was 2.95/100,000 in males versus 1.09/100,000 in females. Most EATLs were localized in the proximal small intestine and the diagnosis was made by surgical resection in the majority of cases. CONCLUSIONS: EATL is a rare disease with an incidence of 0.10 per 100,000 inhabitants per year, occurring in older age, with a peak incidence in the 7th decade. The tumour is mainly localized in the proximal small intestine. Although uncomplicated CD is twice as frequent in female patients, EATL is more prevalent in males.