Background: There have been studies and reports describing the role of fine needle aspiration cytology (FNAC) in multiple myeloma (MM) and extra medullary plasmacytomas (EMP). Here, we present a case of solitary, extraosseous plasmacytoma diagnosed by FNAC which was subsequently found to have monoclonal gammopathy.
Case Report: A 68 year-old-male presented with history of chest wall swelling. Computed tomographic (CT) scan showed it to be a soft tissue mass involving the third and fourth intercostal spaces. ESR was increased. FNAC showed features of plasmacytoma with typical and atypical plasma
cells. Further investigations showed no obvious osteolytic lesions and 3% of marrow plasma cells, which excluded multiple myeloma. However, the biopsy taken from the swelling supported the cytologic diagnosis of plasmacytoma with evidence of amyloid deposit and a monoclonal expression of κ (kappa) immunoglobulin light chains. Serum electrophoresis showed a distinct M-band. A diagnosis of extraosseous plasmacytoma with monoclonal gammopathy was considered and the patient was clinically managed as a case of solitary
plasmacytoma.
Conclusions: The present case highlights the utility of simple FNAC procedure as an important initial diagnostic tool in the investigation of plasma cell dyscrasia presenting with a soft tissue mass lesion.

Keywords: FNAC, EMP, chest wall, extraosseous, soft tissue, Plasmacytoma, monoclonal, gammopathy