Primary tonsillar lymphomas according to the new World Health Organization classification: to report 87 cases and literature review and analysis

The present study aimed to define the natural history, World Health Organization (WHO) classification, prognostic factors, and treatment outcome of 87 patients with primary lymphoma of the palatine tonsil and literature review and analysis. Between 1990 and March 2008, 87 consecutive patients diagnosed with primary lymphoid malignancy of the palatine tonsil. All pathologic specimens were reviewed and reclassified according to the recent WHO classification. To investigate the association of tonsillar lymphomas with Epstein-Barr virus (EBV), in situ hybridization was performed for 24 tonsillar lymphomas (23 diffuse large B-cell lymphoma (DLBC) and one classic Hodgkin’s disease) and ten normal tonsils as control group. In literature review, we found 26 major related series including 1,602 patients with primary tonsillar lymphoma. The median age of our patients was 52 years (range 11–86 years). There were 39 women and 48 men with a median follow-up of 67 months for living patients. The vast majority (95%) of patients had B-cell phenotype. DLBC was the most frequent histology. In situ hybridization revealed none of 23 DLBC to be positive for EBV. The 5-year disease-free and overall survival rates were 78.9% and 86%, respectively. In the literature review and by analyzing the data collection from 26 major reported series, the median age was 55 years and male/female ratio was 1.3:1. Intermediate grade tumors consisted of 72% of all tonsillar lymphomas and B-cell lymphomas constituted 82% of all cell immunophenotypes. The 5-year disease-free and overall survival rates were 61% and 67%, respectively. The vast majority of tonsillar lymphomas are of B-cell origin and with intermediate to high-grade histology. These neoplasms tend to present in early stage disease and to have favorable outcome. WHO classification predicts more accurately treatment outcome of patients with tonsillar lymphoma. The association of DLBC in the palatine tonsil with EBV infection is infrequent.