Recent progress in follicular lymphoma in Japan and characteristics of the duodenal type

Abstract

The incidence of lymphoma has rapidly increased over the last 40 years in Japan, following a trend that is very similar to that of breast cancer. In particular, the relative frequency of follicular lymphoma (FL) has reached that in Western countries. Given its indolence, a “watch‐and‐wait” approach is often applied to FL patients. We have shown that FL is often detected in the second portion of the duodenum and has a distinct follicular dendritic cell distribution and heavy chain variable usage similar to mucosa‐associated lymphoid tissue (MALT) lymphoma. Although the t(14;18)(q32;q21) frequency is the same as in the nodal subtype of FL, there are also ongoing mutations, immunopositivity for cluster of differentiation 10 and B‐cell lymphoma (BCL)6, and overexpression of BCL2. Gene expression profiling has shown that it is more similar to gastric MALT lymphoma than to nodal FL. Duodenal‐type FL lacks the activation‐induced cytidine deaminase (AID) expression observed in nodal ones, although this may be compensated for by BTB domain and CNC homolog 2. Based on these findings, duodenal‐type FL has been included in the Revised 4th edition of the World Health Organization classification published in late 2017.

Upward trend in follicular lymphoma among the Korean population: 10-year experience at a large tertiary institution

“…Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma (NHL) in Western countries and accounts for 20% to 35% of all lymphomas [ 1 , 2 ]. In Asia, until recently, the incidence has been characteristically low, at approximately 5% to 10% of all lymphomas in most studies [ 3 , 4 ]. However, the relative proportion of FL in many Asian populations has increased rapidly in recent years, and FL is now the second most common low-grade B-cell lymphoma after mucosa-associated lymphoid tissue lymphoma in Asia [ 3 , 5 - 7 ].…”

“…However, the relative proportion of FL in many Asian populations has increased rapidly in recent years, and FL is now the second most common low-grade B-cell lymphoma after mucosa-associated lymphoid tissue lymphoma in Asia [ 3 , 5 - 7 ]. The proportion of FL to NHL increased from 8.1% to 23.5% in China and 5% to 20% in Japan [ 3 , 4 , 7 , 8 ]; additionally, an increase in the proportion in Korea, from 3.4% to 4.8% between 1999 and 2012, has been reported [ 9 , 10 ].…”

Linfoma folicular duodenal primario: reporte de caso y revisión de la literatura

“…La alteración genética distintiva de los LF es la translocación t (14;18) (q32; q21) de los genes de la cadena pesada de la inmunoglobulina (Ig). Además, se han descrito ciertas similitudes en el perfil genético con el linfoma MALT, estas similitudes están asociadas con la estimulación antigénica en inflamación crónica, y se sospecha que el LDF puede seguir un curso similar al linfoma MALT, que se origina sobre inflamación preexistente (6) .…”

Recent Advances in Digestive Tract Tumors: Updates From the 5th Edition of the World Health Organization “Blue Book”

“…Even though molecular testing will demonstrate the same t(14;18)(q32;q21) translocation that is seen in follicular lymphoma, comparative genomic hybridization studies suggest similarities to extranodal marginal zone lymphoma. 128 The diffuse large B-cell lymphoma (DLBCL) content is greatly expanded in the 5th edition, 1 dividing DLBCL into germinal center B-cell and activated B-cell profiles, noting that germinal center B-cell DLBCLs are more often CD10, GCET1, and LMO2 positive, unlike the activated B-cell type, which more frequently expresses MUM1 and FOXP1. The most common site of extranodal DLBCL is the gastrointestinal tract, most commonly the stomach and ileocecal region.…”