Gastric plasmablastic lymphoma – case report

Abstract

Plasmablastic lymphoma (PBL) is a rare, clinically aggressive B-cell lymphoma which was initially described involving the oral cavity of HIV positive patients. Subsequent reports have expanded its clinical spectrum to involve a broad spectrum of sites, other forms of immunosuppression and elderly patients without specific immune compromise. Gastric involvement is documented but uncommon, with seven reported cases of gastric plasmablastic lymphoma in the literature. We describe a case of gastric PBL in a non-immunocompromised 71 year old male. Endoscopic gastric biopsy showed an atypical sheet-like proliferation of large atypical cells with a range of plasma cell differentiation, including mature plasma cells, atypical binucleate cells, plasmablasts and immunoblasts. The tumour cells were positive for CD 45 (weak), CD 138, MUM-1, and EBV EBER in situ hybridisation, and showed Kappa light chain restriction. It is important to consider plasmablastic lymphoma in the differential diagnosis of large cell malignancies at any site and patient population, as weak CD 45 expression and lack of B and T cell markers may otherwise delay the diagnosis of lymphoma.