Nation-wide study of lethal mid-line granuloma in Japan: frequencies of wegener's granulomatosis, polymorphic reticulosis, malignant lymphoma and other related conditions.

Lethal mid-line granuloma (LMG) is a clinical term, and it is histologically composed of Wegener's granulomatosis (WG), polymorphic reticulosis (PR), and malignant lymphoma (ML). WG is an inflammatory disease, and PR and ML are considered to represent a neoplastic proliferation of lymphoreticular cells. In the present report, a nation-wide study on LMG in Japan is compared with a study from the UK, to examine differences in frequencies of each disease in Eastern and Western countries. A total of 340 cases of LMG were examined. On the basis of histological and clinical findings, these cases were categorized as 68 WG, 129 PR, 92 ML, 44 chronic inflammation not specified, and 7 other related conditions. The crude frequencies of WG, PR, and ML per 100,000 outpatients of ENT clinics in Japan and England were 4, 8 and 6, respectively and 8, 4 and I, respectively. The predominance of malignant lymphoproliferative diseases to WG in Japan (3.5:1) was in marked contrast to the situation in the UK (1:1.6). A review of the pertinent literature suggests a clustering of malignant lymphoproliferative diseases of the nose among Mongolian ethnic groups.