Synchronous Primary Pulmonary Marginal Zone B-Cell Lymphoma and Large B-Cell Lymphoma

Abstract SESSION TYPE: Pleural Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: Pleural effusion is the most common manifestation of pleural disease, with etiologies ranging from cardiopulmonary disorders to malignant diseases. We present an unusual etiology for a right-sided pleural effusion in a 42-year-old female.CASE PRESENTATION: A 42 year-old female was evaluated for dry cough and progressive dyspnea on exertion. She had intermittent fevers and a 15 kg weight loss. Auscultation revealed diminished breath sounds at the right base with dullness to percussion. The chest X-ray showed a large right pleural effusion and a right upper lobe mass (figure 1). CT scan of the chest confirmed the chest X-ray findings and identified a second mass in the right lower lobe (figure 2). PET/CT scan revealed multiple pulmonary masses which were FDG avid. Pleural fluid analysis showed numerous small lymphoid cells without evidence of malignancy. The cultures of the pleural fluid were negative. Flow cytometry of the pleural fluid showed a polymorphous lymphoid population. Immunohistochemical stains and molecular studies of the right lower lobe transbronchial biopsies were consistent with marginal zone B-cell lymphoma. The right upper lobe transbronchial biopsies showed focal areas of large pleomorphic B-cells, suggestive of a large B-cell lymphoma. Based on the available data, a diagnosis of stage IV large B-cell lymphoma, which transformed from a low grade marginal zone lymphoma, was made. The patient's clinical course was favorable with chemotherapy.DISCUSSION: Primary pulmonary marginal zone B-cell lymphoma (P-MZL) accounts for less than 0.4% of all malignant lymphomas (1). Predominantly, the patients present with cough, dyspnea, and constitutional symptoms and are frequently treated with antibiotics for presumed pneumonia. The majority of patients are diagnosed by bronchoscopy. Up to 14% of cases had associated pleural effusions and hilar adenopathy is common (2). The FDG-PET/CT scan has a high sensitivity and specificity (about 95%) in detecting occult lymphoma sites. Morphologically, marginal zone B-lymphocytes demonstrate small to medium size, irregular nuclei with dispersed chromatin. The lack of CD5 expression discriminates between MZL and chronic lymphocytic leukemia/small lymphocytic lymphoma, and the presence of CD10 expression favors follicular lymphoma.CONCLUSIONS: We presented a rare case of primary P-MZL synchronous with a large B-cell lymphoma, in an attempt to raise the awareness of this rare disease as a possible etiology for pleural effusion.1) Ahmed S, Siddiqui AK, Rai KR. Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma. Cancer Invest 2002; 20(7-8):1059-1068.2) Stefanovic A, Morgensztern D, Fong T et al. Pulmonary marginal zone lymphoma: a single centre experience and review of the SEER database. Leuk Lymphoma 2008; 49(7):1311-1320.DISCLOSURE: The following authors have nothing to disclose: Catalin Nicola, Michael PetersonNo Product/Research Disclosure InformationUCSF Fresno MEP, Fresno, CA.