Primary mediastinal large B-Cell lymphoma diagnosis at core biopsy

Abstract

Primary mediastinal large B-cell lymphoma (PMBL) represents a distinct entity with unique clinicopathological features and a molecular gene expression signature reminiscent of nodular sclerosis subtype of classical Hodgkin's lymphoma. Recent studies suggest that it has a more favourable outcome than diffuse large B-cell lymphoma. It is a clinically aggressive B-cell lymphoma that arises from thymic medullary B cells and present as a locally invasive anterior mediastinal mass. Due to location of the tumour an excisional biopsy is not usually possible and small biopsies may be non-diagnostic due to inadequate sampling, crush artefacts or fibrosis obscuring the lesion. The tumour site, young age group, female predominance, immunohistochemistry, flow cytometry and gene rearrangement studies may help to establish the diagnosis. This is a case of primary mediastinal B-cell lymphoma (PMBL) diagnosed at core biopsy.