Classification of malignant lymphoma subtypes in Korean patients: a report of the 4th nationwide study

Abstract

To determine the relative frequency and change of malignant lymphoma in Korea according to the 4th World Health Organization (WHO) classification and compare with previous reports. Between 2015 and 2016, 7737 new patients with malignant lymphoma were enrolled from 31 institutes, with their clinicopathologic information obtained, and evaluated for the relative frequency of lymphoma subtypes. The relative frequency of non-Hodgkin lymphoma (NHL) was 94.8%, and that of Hodgkin lymphoma (HL) was 5.2%. B cell lymphomas accounted for 83.1% of all NHLs; T/natural killer (NK) cell lymphomas, 16.4%; and immunodeficiency-associated lymphoproliferative disorders, 0.5%. The most common NHL subtypes were diffuse large B cell (41.5%), extranodal marginal zone (MALT, 19.8%), follicular (7.5%), NK/ T cell (4.2%), and peripheral T cell lymphomas, not otherwise specific (PTCL, NOS, 3.4%). Nodular sclerosis was the predominant HL subtype (48.5%), followed by mixed cellularity (28.7%), lymphocyte-rich (6.8%), lymphocyte-depleted (1.5%), lymphocyte-predominant (2.8%), and unclassified HL (11.8%). Compared with a previous report, increased B cell lymphomas (77.6-83.1%) and slightly decreased NK/T cell lymphomas and PTCL were observed. The incidence of follicular lymphoma increased by more than 2.5-fold (2.9-7.5%). Incidence rates of newly diagnosed lymphomas were lower for HL and higher for extranodal NHL, MALT, and nasal type NK/T cell lymphomas in Korea than those in Western countries. A slight increase in the relative frequency of B cell lymphoma and a prominent increase in follicular lymphoma may be attributed to refined diagnostic criteria and Westernized disease patterns.

Genetic profiles of subcutaneous panniculitis-like T-cell lymphoma and clinicopathological impact of HAVCR2 mutations

“…SPTCLs account for <1% of all NHLs worldwide 1 and 0.3% of all malignant lymphomas in the Republic of Korea. 2 SPTCL typically affects young individuals, with a median patient age of 36 years and a female sex bias. 3 Histopathologically, SPTCL is characterized by CD8-positive T cells infiltrating into subcutaneous adipose tissue, with rimmed individual fat cells in a lace-like pattern.…”

Risk of non-Hodgkin lymphoma in breast cancer survivors: a nationwide cohort study

“…Additionally, the type of NHL also differs with respect to western. Compared to Western countries, Korea has a higher frequency of follicular lymphoma and NK/T cell lymphomas which are relatively more strongly associated with incident breast cancer [ 40 ]. Therefore, our findings may not be generalizable to other settings with different incidence rates for different types of NHL.…”

Morphologic variant of follicular lymphoma reminiscent of hyaline-vascular Castleman disease

“…The incidence of FL in Korea is increasing over time; compared with the 2005-2006 statistics [6], the proportion of FL has increased 2.5-fold from 2015-2016, becoming the third most common form of B-cell NHL in Korea, following diffuse large B-cell lymphoma and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [2]. Due to the overall increase in incidence, pathologists are more likely to encounter FL variants in daily practice; therefore, awareness of rare morphological variants is important for accurate identification and diagnosis.…”