Blood stem cell transplantation to treat cystic lung light chain deposition disease.

Light chain deposition disease (LCDD) is a rare disease resulting from non-amyloid immunoglobulin (Ig) light chain deposition in tissue. In systemic LCDD, plasma cell dyscrasia is common and renal involvement is almost always present, sometimes with damage to other organ systems (cardiac, hepatic and neurological systems). LCDD can be limited to the lungs, presenting as multiple cystic lung disease, nodules or bronchiectasis. Cystic lung related to LCDD (CL-LCDD) was recently described in patients referred for lung transplantation to treat end-stage multiple cystic lung disease [1]. In the reported cases, blood and bone marrow examinations did not reveal clonal plasma cell proliferation. Here we report the first case of CL-LCDD revealing a B-cell extrapulmonary lymphoproliferative disorder and the results of treatment for the underlying haematological disease with autologous peripheral blood stem cell transplantation during the CL-LCDD. Despite respiratory insufficiency, lung transplantation was actually not considered because of the underlying disease.