880: PULMONARY AMYLOIDOSIS ASSOCIATED WITH B CELL LYMPHOPROLIFERATIVE DISORDER: A CASE REPORT

Abstract

Introduction: Amyloidosis is caused by the deposition of misfolded autologous proteins in various organs and can be systemic or localized. AL amyloidosis is often associated with plasma cell disorder but here we report a rare case of Isolated Nodular Pulmonary Amyloidosis associated with a B cell Lymphoproliferative Disorder. Description: An 89 year old female with a past medical history of pulmonary arterial hypertension presented to the clinic with chronic stable exertional dyspnea and no associated symptoms. Four years prior, a computed tomography (CT) of the chest showed multiple bilateral calcified and noncalcified lung nodules with no further work-up. Chest X-ray performed at current presentation revealed extensive pulmonary reticulonodular shadowing at the peripheries with extensive fibrotic changes and scattered nodules. Subsequent CT chest showed interval increase of several bilateral nodules. A PET-CT showed multiple mildly hypermetabolic nodules. A CT guided needle biopsy of an FDG avid right upper lobe nodule measuring 1.5 x 1.4 cm was performed. Pathology was significant for homogenous acellular amorphous material with an entrapped plasma cell infiltrate. Congo red stain confirmed the presence of apple green birefringence diagnostic of amyloidosis. Immunohistochemistry showed a mixture of kappa-positive and lambda-positive cells, with kappa-positive cell predominance suggestive of an atypical plasma cell population. Clonal gene rearrangements were detected in both the immunoglobulin heavy chain and light chain gene which highly suggested the presence of a B-cell Lymphoproliferative Disorder. The patient was subsequently referred to oncology for further management. Discussion: Pulmonary Amyloidosis is an incidental radiological finding with patients being asymptomatic. CT chest may show lung nodules with/without calcifications. Biopsy is required for diagnosis with radiology guided fine needle aspiration. Isolated pulmonary amyloidosis has a good prognosis but should trigger evaluation for autoimmune disorders and B cell lymphoproliferative disorders as in this case with early referral and treatment of the underlying disorder.