Distribution and Pathology Characteristics of Non Hodgkin Lymphoma in Peru: A Study of 1014 Cases Using WHO Classification of Lymphoid Neoplasm.

BACKGROUND: The frequency of various subtypes of non-Hodgkin’s lymphoma (NHL) differs in various regions worldwide.

OBJECTIVE: To investigate the clinical and pathological features of non-Hodgkin’s lymphoma (NHL) and to evaluate the applicability of the new WHO classification of lymphoid neoplasms.

METHODS: According to the new WHO classification, a total of 1014 cases of non-Hodgkin’s lymphoma diagnosed during the period 2002–2006 were reviewed and reappraised with their morphological, immunological and clinical characteristics in one general hospital from Lima, Peru. All cases corresponded >18 years old.

RESULTS: There were 535 males and 479 females, mean age was 62.1 years (range 18 – 97 years) and the median was 64 years. B-cell neoplasms accounted for 763 cases (75.2%) and T/NK-cell neoplasms for 189 (18.6%). Sixty two cases (6.1%) were not classified. It was seen compared to that in the other Asian countries. Indolent lymphomas accounted for 17%, and aggressive ones for 83%. Among indolent lymphomas follicular grade I and II were the most common subset while MALT was second with low frequency. Among the aggressive lymphomas diffuse large cell lymphoma (DLCL) was the most common subtype, and accounted for 58.8% of all B cell lymphomas. Mantle and Burkitt lymphoma were very low incidence. Among the T cell lymphomas, peripheral T cell lymphomas, mycosis fungoides, Adult T Lymphoma/Leukemia (ATLL), T/NK nasal type Lymphoma were the most common subtypes. Nodal NHL occurred in 52% and extranodal in 48% of the cases. The more common extranodal presentation was stomach (14.1%), skin (8.1%), small intestine (2.9%) and nose (2.3%)

CONCLUSIONS: The high incidence of T cell lymphomas, extranodal presentation and reduced frequency of indolent lymphoma in the current study is comparable to that reported from Asian countries.