145 Plasmacytoma: An Unusual Extramedullary Presentation

Abstract

Case PresentationA 53 year old white male presented with complaints of left-sided headaches radiating to the posterior left neck. The patient described the pain as intermittent and dull in nature and also mentioned some worsening of disequilibrium but denied vertigo. CT and MRI head revealed a retropharyngeal mass with invasion of virtually the entire skull base, including the clivus, medial temporal bones, as well as the medial sphenoid bones and a mass within the sphenoid sinus. HEENT examination was unremarkable. There were no other focal neurologic deficits.Diagnostic ProceduresFlexible laryngoscopy: fullness in the area of adenoids. Image-guided biopsy with transsphenoidal approach.PathologyA densely cellular neoplasm. Sheets of cells have hyperchromatic nuclei, occasional nucleoli, and rims of cytoplasm. There are scattered mitoses.ImmunohistochemistryCD138 positive, lamda positive, kappa negative.Final Pathologic Diagnosis1. Sphenoid sinus mass; plasmacytoma.Treatment CourseBMA, plasma cells 5-10%. Bone survey; no lytic lesions. S. proteins 7.6 g/dL, Alb. 4.4 g/dL. B2mic. 2.3 mg/L. SPEP IgG 1.04 g/dL, UPEP negative. At present the patient is receiving radiation therapy. We will obtain post radiation CT head to assess the response to therapy.DiscussionThe diagnosis of an extramedullary plasmacytoma depends upon the demonstration of a monoclonal plasma cell tumor at an extramedulary site with no evidence of MM based upon bone marrow examination and roentgenographic studies, absence of an M-protein in serum and/or urine, and no related organ or tissue impairment. The treatment of choice for extramedullary plasmacytoma is tumoricidal radiation in a dosage of 40 Gy over a four-week period. Adjuvant chemotherapy does not lower the relapse rate or increase disease-free survival in this group of patients.