current lymphoma classification: new concepts and practical applications-triumphs and woes

The World Health Organization [WHO] classification of lymphomas updated in 2008 represents an international consensus for diagnosis of lymphoid neoplasms based on the recognition of distinct disease entities by applying a constellation of clinical and laboratory features. The 2008 classification has refined and clarified the definitions of well-recognized diseases, identified new entities and variants, and incorporated emerging concepts in the understanding of lymphoid neoplasms. Rather than being a theoretical scheme this classification has used data from published literature. Recent knowledge of molecular pathways has led to identification and development of new diagnostic tools, like gene expression profiling, which could complement existing technologies. However, some questions remain unresolved, such as the extent to which specific genetic or molecular alterations define certain tumors. In general, practical considerations and economics preclude a heavily molecular and genetic approach. The significance of early or precursor lesions and the identification of certain lymphoid neoplasms is less clear at present, but understanding is evolving. The borderline categories having overlapping features with large B-cell lymphomas, as well as some of the provisional entities, are subject to debate and lack consensus in management. Lastly, the sheer number of entities may be overwhelming, especially, for the diagnosing pathologist, who do not see enough of these on a regular basis

Successful treatment of steroid-refractory autoimmune thrombocytopenia associated with Castleman disease with anti-CD-20 antibody [rituximab]

Multicentric Castleman disease [MCD] is a lymphoproliferative disorder of incompletely understood etiology and with various clinical presentations. The best therapeutic option for this disease is not well established. MCD is known to be associated with autoimmune phenomena. A 70-year-old female patient of MCD with progressive nodal disease associated with autoimmune thrombocytopenia failed steroid treatment and showed a transient response to intravenous immunoglobulin. The patient achieved complete recovery of her platelet count and a very good response in nodal disease after 3 weekly doses of anti-CD-20 antibody [rituximab]. Anti-CD20 antibody treatment could be a good therapeutic option for MCD, mainly when associated with immune-related disorders

Untreated primary thyroid lymphoma in an elderly woman

A 92- year-old otherwise healthy female was diagnosed in another institution with thyroid lymphoma on fine needle aspirate [FNA] five years back. The patient repeatedly refused further management. Due to the rapid increase in the size of her tumor, shortness of breath and stridor, she was transferred to our institution and required intubation in the intensive care unit. She had 30x15 cm neck mass extending bilaterally and to the upper chest with an engorged neck and chest veins [Figure 1, A and B; Figure 2A]. Her thyroid-stimulating hormone was 1109 mU/ L [normal range, 0.27 to 4.2 mU/L]. Flow immunophe-notyping from the thyroid FNA specimen confirmed a CD19, CD20, and CD22 expressing monoclonal B-cell population, high forward and side scatter showing surface kappa light chain restriction. CD 10 and CD5 were not co-expressed. These features and morphology were consistent with a large B-cell lymphoma. She received cyclophosphamide 500 mg intravenously and one dose of vincristine 2 mg intravenously and dexamethasone 40 mg intravenously for 5 days. Her tumor was reduced by 70% after five days. Her shortness of breath and stridor increased and chest x-ray showed infiltrates and then aspiration pneumonia [Figure 2B. She developed febrile neutropenia, Klebsiella pneumoni-at bacteremia, deteriorated rapidly, developed multiple organ system failure and died fourteen days after receiving chemotherapy