OBJECTIVETo study the immunophenotype and gene rearrangement pattern of pulmonary lymphomatoid granulomatosis.

METHODSNine cases of pulmonary lymphomatoid granulomatosis, included 5 cases of open lung biopsy, 3 cases of lobectomy specimen and 1 case of autopsy, were retrospectively analyzed by immunohistochemistry, in-situ hybridization for Epstein-Barr virus-encoded RNA, immunoglobulin and T-cell receptor gene rearrangement studies.

RESULTSThe age of patients ranged from 3 to 59 years. The male-to-female ratio was 3: 6. Histologically, all cases showed lymphocytic infiltration surrounding the blood vessels and in the perivascular areas. Most of these lymphoid cells expressed T-cell marker CD3. There were also variable numbers of CD20-positive B cells. The staining for CD56 was negative. According to the WHO classification, there were 4 cases of grade I , 1 case of grade II and 4 cases of grade III lesions. Six cases had gene rearrangement studies performed and 3 of them demonstrated clonal immunoglobulin gene rearrangement (including 1 of the grade II and 2 of the grade III lesions). No T-cell receptor gene rearrangement was detected.

CONCLUSIONSPulmonary lymphomatoid granulomatosis may represent a heterogeneous group of lymphoproliferative disorders. Some of the cases show B-cell immunophenotype and clonal immunoglobulin gene rearrangement, especially the grade II and grade lesions. They are likely of lymphomatous nature.