PULMONARY MALIGNANT-LYMPHOMA OF MUCOSA-ASSOCIATED LYMPHOID-TISSUE (MALT) ARISING IN A PEDIATRIC HIV-POSITIVE PATIENT

A malignant lymphoma arising in the lung of a pediatric HIV-positive p atient exhibited histologic and clinical features of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). Clinically, the neoplasm consisted of a 4-cm mass in the left-upper lobe of the lung o f a 7-year-old girl, The lung mass was surgically resected. Monoclonal immunoglobulin heavy and light chain gene rearrangements were shown b y Southern blot. Monoclonality of light chain expression was demonstra ted by immunohistochemistry. Coexpression of Leu-22 (CD43) by the tumo r cells supported the diagnosis of lymphoma. The remainder of the pulm onary parenchyma distal to the mass was associated with pulmonary lymp hoid hyperplasia/lymphocytic interstitial pneumonitis, which may have been a predisposing factor. Gastric MALT lymphomas have recently been described in adult HIV-antibody-positive patients. Ours represents the first reported case of a pulmonary MALT lymphoma in a pediatric HIV-p ositive patient, In addition, at age 7, this is the youngest patient r eported with a MALT lymphoma.