ABSTRACT

Rationale and Objectives:

Multiple myeloma is a neoplasm of plasma cells resulting in bone marrow proliferation of these cells. It is more commonly diagnosed in older patients presenting only constitutional symptoms. Plasma cell dyscrasia may uncommonly involve other sites (extramedullary plasmacytomas), with lung involvement being rare. Here, we report such a case.

Case:

A 72-year-old smoker, hypertensive male was admitted for a two-month history of recurrent productive cough, weight loss, and malaise. Previous workup was remarkable for a pulmonary mass with mediastinal lymphadenopathy. Bronchoscopy with cryobiopsy revealed monomorphous plasmacytoid infiltrate with atypical features. Baseline CBC showed a normocytic normochromic anemia. Serum protein electrophoresis showed findings consistent with a monoclonal gammopathy. The bronchial cryobiopsy and bone marrow core biopsy revealed immunohistomorphologic features supportive of plasmacytosis, involving both the respiratory and bone marrow tissues (10-15% bone marrow plasma cells). Investigation for lytic lesions was carried out using CT scan which revealed multiple sites of osteopenia. The totality of evidence favors the diagnosis of extramedullary myeloma of the lungs. The patient was started with a Bortezomib-based regimen. A repeat Serum Protein Electrophoresis showed a significant decreased monoclonal peak after 2 cycles of Bortezomib. Immunotyping of stored patient serum shows a peak consisting of monoclonal IgG Lambda proteins supporting our diagnosis.

Discussion and Summary:

In general, the prognosis of extramedullary pulmonary plasmacytoma is poor. Despite several advances in modern medicine, there are no consensus guidelines in the treatment of extramedullary myeloma, and it remains an incurable disease albeit a treatable one.