Non-Hodgkin lymphoma of the Waldeyer's ring: clinicopathologic and therapeutic issues

Extranodal non-Hodgkin lymphoma (NHL) in head and neck region is most commonly seen in the Waldeyer's ring. Waldeyer's ring is a unique subtype of mucosa associated lymphoid tissue (MALT), which shows rarity of low-grade or MALT-type lymphomas and a high incidence of diffuse large B cell lymphoma (DLBCL). The commonest histology is DLBCL with natural history similar to primary nodal NHL. However, high association with gastrointestinal involvement is reported. The diagnostic workup is similar to that of the usual nodal NHL, and in absence of a specific staging system, the Ann Arbor staging is followed. As compared with T-cell subtypes, B-cell phenotypes are less likely to present with mucosal ulceration, epitheliotropism and angioinvasion. Stage of disease, histology and use of combined modality treatment have been proposed as significant prognostic factors. Treatment has evolved from the use of extended field radiotherapy (RT) alone to the use of combined chemotherapy and RT leading to almost doubling of survival. Advances in pathology and further risk stratification of patients into prognostic groups could lead to the development of novel therapeutic strategies to improve outcome.