Pitfalls in diagnostic hematopathology -- Part II.

The overlapping features of malignant lymphomas create a diagnostic "grey zone" , and lead to the invention of "grey zone lymphomas". There are several major grey zone lymphomas: 1) Lymphomas with overlapping features of Hodgkin lymphoma and large B-cell lymphoma; 2) Lymphomas with overlapping features of Burkitt lymphoma and diffuse large B-cell lymphoma; 3) Lymphomas with overlapping features of nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte rich large B-cell lymphoma; 4) Lymphomas with overlapping features of Hodgkin lymphoma, anaplastic large cell lymphoma (ALCL) and peripheral T-cell lymphoma (PTCL); 5) T-cell classical Hodgkin lymphoma and ALCL-HL. The second review of this series will be dedicated to discussion of the "grey zone" features of the lymphomas and how to narrow down the "grey zone" between those lymphomas.

Lymphoma subtype incidence rates in children and adolescents: first report from Brazil

Lymphoma is the third most common pediatric malignancy. The purpose of this study was to analyze the incidence rates of lymphoma in children and adolescents in Brazil. All cases of Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), and Burkitt lymphoma (BL) were extracted from 14 population-based cancer registries (PBCRs) from 2000 to 2005, and included children and adolescents 0-19 years old. Analyses included age-adjusted incidence rates (AAIRs) and age-specific incidence rates (ASIRs) by each PBCR. A social exclusion index (SEI) was built and used as proxy for socioeconomic status (SES) levels. Correlations between SES and incidence rates were investigated using Spearman's test. The median incidence of lymphoma was 22.7/million. AAIRs of lymphomas varied from 12.9 (Salvador) to 34.5 per million (São Paulo). Median AAIR was 8.8/million, 9.8/million, and 2.9/million for NHL, HL, and BL, respectively. In all PBCRs except that of Recife, AAIR was slightly higher in males than females. The median ASIR was highest for HL (18.5/million) at 15-19 years for both genders. For NHL there were two peaks for ASIR: 11.1/million (1-4 years of age) and 13.2/million (15-19 years of age). The median ASIR for BL was highest among children aged 1-4 years (4.7/million) and in males. Higher SEI correlated with higher incidence of HL (P = 0.06), whereas rates of NHL and BL did not correlate with SEI. Borderline different incidence rates were observed in HL correlated with cities with higher SEIs. Incidence rates of lymphomas in Brazil do not differ compared to rates reported worldwide, although SES differences deserve further investigation

Hodgkin's lymphoma: basing the treatment on the evidence.

This paper examines the evidence available to guide treatment decisions in three areas of Hodgkin's lymphoma management. In Section I Dr. Evert Noordijk describes evolving strategies for patients with early stage disease outlining the eras during which the focus has changed from initially accomplishing cure through refining and intensifying the treatment to one of maximizing cure rates and finally into a patient-oriented era in which the twin goals of maintaining high rates of cure and minimizing late toxicity are being achieved. In Section II Dr. Sandra Horning reviews the way in which the cooperative groups of North America and Europe have built upon initial observations from single centers to assemble the trials that have defined the treatment for advanced stage Hodgkin's lymphoma. Over a period of almost three decades, these well-constructed trials have defined a current standard of treatment, ABVD chemotherapy and are now investigating innovative approaches to move beyond this standard. She also indicates the need to appreciate diagnostic factors and the implications of prognostic factor models for the design and interpretation of clinical trials. In Section III Dr. Joseph Connors summarizes the evidence available to inform our choice of treatment for the uncommon but important entity of lymphocyte predominance Hodgkin's lymphoma. Once again, the guidance that can be derived from carefully conducted clinical investigation is used to address the issues surrounding choice of treatment, reasonable monitoring in long term follow-up and the clear-cut need to base diagnosis on objective immunohistochemical evidence.