Subcategories of histiocytic lymphoma: Associations with survival and reproducibility of classification. The southeastern cancer study group experience

Abstract

Five pathologists reviewed histologic slides from 134 cases of histiocytic lymphoma and subclassified these cases using the Lukes-Collins classification system. Of 98 morphologically subclassifiable cases, 85 were distributed among three categories, each presumed to represent a lymphoma of follicular center cell origin. The remaining 12 cases were classified among three additional categories. The cases within the three follicular center cell categories, considered collectively, had a significantly better survival than did the cases within the other three categories considered as a whole. The pathologists classified cases generally as being of a follicular center cell type with a high degree of reproducibility, but their individual classifications varied significantly with respect to more specific morphologic categories. Suboptimal quality of histologic sections was a significant factor contributing to problems in morphologic classification. Ancillary immunologic techniques may be required for definitive subclassification of large cell lymphomas.