抄録
A case of malignant midline oral ulceration in a 51-yr-old woman is reported. Midline granuloma is rare, well documented and has a variety of names. Lethal midline granuloma is a malignant lymphoma, most commonly NK or T cell lineage. The patient developed recurrent oral ulceration over a period of a year requiring several biopsies before the correct diagnosis was made. A high grade NK/T cell lymphoma with an angiocentric growth pattern was confirmed, the lymphoma cells expressing T-cell markers (CD3, CD43) and co-expressing CD30. Natural killer T-cell markers (CD56 and CD57) were not expressed but there are strong expression cytotoxin granule associated proteins granzyme B and perforin markers of activated NK cells. No association with Epstein-Barr virus was found with immunohistochemistry and in-situ hybridisation. The patient failed to respond to chemotherapy and died several months later. This case illustrates the difficulty in making the diagnosis of T-cell lymphoma as the oral ulcers often show secondary inflammatory changes, which mask the lymphoma cells, and multiple biopsies may be required to make the correct diagnosis.
