Lymphomatoid granulomatosis--evidence of a clonal T-cell origin and an association with lethal midline granuloma.

Lymphomatoid granulomatosis and lethal midline granuloma are both characterized histologically by atypical pleomorphic angiocentric infiltrates. Whether these conditions are malignant lymphoproliferative disorders remains controversial. Here we report the results of studies carried out in a patient with coeliac disease, who developed recurrent self-healing subcutaneous nodules with the histological changes of lymphomatoid granulomatosis and an invasive nasal tumour with the histological features of lethal midline granuloma. The patient subsequently also developed an erythrophagocytic syndrome. Immunocytochemical labelling of both cutaneous and nasal lesions demonstrated a predominant population of T cells with a CD4-negative CD8-positive phenotype. Analysis of DNA from cutaneous tissue revealed a discrete rearrangement of the beta and gamma T-cell receptor genes. These findings suggest that lymphomatoid granulomatosis is a clonal T-cell lymphoproliferative disorder and its association with lethal midline granuloma indicates that both conditions may have a common histogenesis.