Stage is a better prognostic indicator than morphologic subtype in primary noncutaneous T-cell lymphoma.

The authors reviewed 28 primary noncutaneous T-cell lymphomas, referred to the Comprehensive Cancer Center Amsterdam, using the updated Kiel classification. Clinical course was related with stage of disease, morphologic subtype, and immunophenotype of the tumor cells. The incidence of primary noncutaneous T-cell lymphomas was 4.1 cases per 1,000,000 people per year. Morphologic classification was difficult and arbitrary. Immunohistochemistry contributed considerably in diagnosis of this group of tumors. All primary noncutaneous T-cell lymphomas had a poor prognosis, with no significant difference between predominantly small cell (low-grade) and large cell (high-grade) tumors. The only parameter significantly correlating with survival was the stage of the disease at presentation. The results suggest that all types of primary noncutaneous T-cell lymphoma are to be considered high grade and that primary localization (cutaneous vs. noncutaneous) and stage of disease at presentation appear to be more important as predictors of clinical outcome than morphologic or immunophenotypic subtype.