Tissue diagnosis should be performed. In general, the most accessible organ involved should be biopsied. Establishing the diagnosis of LYG usually requires an open lung or video assisted thoracoscopic biopsy. Transbronchial lung biopsy has not been rigorously studied. Because of the focal nature of LYG and the fact that it is not bronchocentric, a low diagnostic yield with bronchoscopic transbronchial biopsies is likely.
Skin biopsy is the least invasive.
In all cases, the pathologist should be informed that LYG is clinically suspected to ensure that appropriate studies are performed. A nodular perivascular infiltrate containing plasma cells, lymphocytes, and large atypical mononuclear cells in various stages of maturity is present. This is a destructive lesion due to vessel occlusion by lymphocytic infiltration and subsequent tissue necrosis. Perform analysis for cell phenotype, clonality, and EBV infection. As discussed above, despite the predominance of T cells, the malignant cells appear to be B cells, and the T-cell infiltrate is polyclonal.