SECONDARY PLEURAL INVOLVEMENT BY AN AIDS-RELATED ANAPLASTIC LARGE-CELL (CD30+) LYMPHOMA SIMULATING METASTATIC ADENOCARCINOMA

We report a patient with acquired immunodeficiency syndrome with secon dary pleural and pulmonary involvement by a CD30+ anaplastic large cel l lymphoma (ALCL) that morphologically simulated metastatic adenocarci noma. We describe the morphologic findings bl order to heighten awaren ess that CD30+ ALCL may mimic metastatic adenocarcinoma in a body flui d or bronchial brushing and should be considered in the differential d iagnosis. Primary body cavity based (PCBC) AIDS-related lymphoma is a relatively newly described disease entity with morphologic features br idging ALCL and large cell immunoblastic lymphoma with a CD30+ null im munophenotype. A morphology mimicking adenocarcinoma has not been prev iously described in this entity but should be considered iii a patient with AIDS presenting exclusively with a serous effusion. Appropriate immunoperoxidase staining should aid in these differential diagnoses. (C) 1998 Wiley-Liss, Inc.