Space-associated lymphomas: review of a heterogeneous group of old and new entities

This review discusses a group of distinctive extranodal lymphomas that characteristically arise in anatomic spaces, with emphasis on their pathologic features, and including some historical perspective. The anatomic spaces include normal structures that are normally low-volume potential spaces that may expand due to the presence of fluid, inflammation or cellular infiltrate, such as the pleural cavity, as well as abnormal spaces, including cysts and pseudocysts. These lymphomas include diffuse large B-cell lymphoma associated with chronic inflammation, fibrin-associated large B-cell lymphoma, primary effusion lymphoma, fluid overload-associated large B-cell lymphoma, and breast implant-associated anaplastic large cell lymphoma.