Mature B-cell lymphoma in children and adolescents: International group pathologist consensus correlates with histology technical quality.

In pediatric mature B-cell non-Hodgkin lymphoma, international pathologist diagnostic agreement was previously evaluated using the Revised European-American Lymphoma Classification. Surgical biopsy histology technical quality (HTQ) is variable and may affect diagnostic accuracy. This study evaluated diagnostic agreement correlated with HTQ. Surgical biopsies obtained from international protocol FAB LMB96 Treatment of Mature B-Cell Lymphoma/Leukemia for Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and high-grade B-cell lymphoma Burkitt-like (BLL), were independently reviewed by hematopathologists from 3 national groups (Children's Cancer Group, Société Française d'Oncologie Pédiatrique, and United Kingdom Children's Cancer Study Group) to determine each national diagnosis and a final diagnosis. HTQ grades for microscopic tissue sections included: good; medium; low; inconclusive. Final diagnoses in 187 cases included: BL 87 (47%); BLL 20 (11%); DLBCL 64 (34%); other 16 (9%). HTQ grades included: good 10 (5%); medium 100 (54%); low 75 (40%); inconclusive 2 (1%). The rate of uniform agreement between the national diagnoses was significantly higher with good or medium HTQ (62%) than with low HTQ (33%) (P = 0.001). In conclusion, in pediatric mature B-cell non-Hodgkin lymphoma, international pathologist diagnostic agreement is significantly higher in surgical biopsies with better HTQ. Poor HTQ may adversely impact diagnostic ability and affect prognosis and therapeutic management when different treatment regimens are employed for DLBCL versus BL/BLL.