Extramedullary plasmacytoma presenting as a nasal mass in an immunosuppressed patient: treatment after failed primary radiotherapy

Ear, Nose & Throat Journal, April, 2008 by Ryan Dempewolf, John H. Lee

Abstract

Most of the recent evidence suggests that extramedullary plasmacytoma should be treated initially with radiation, as response rates have exceeded 90% in many studies. Surgery is not considered a primary treatment modality for such tumors. We report the case of a chronically immunosuppressed 43-year-old man with bilateral extramedullary plasmacytomas of the nasal cavities. The right-sided mass was surgically excised, while the left-sided mass was initially treated with radiation. However, the left mass proved to be radioresistant, and it was subsequently excised surgically. The patient showed no evidence of recurrence of either mass at 42 months of follow-up. We believe that the particulars of this case, combined with the results of some recent studies, provide good evidence that surgery should be considered in the treatment of certain cases of extramedullary plasmacytoma.

Introduction

In view of the excellent outcomes, localized primary radiation therapy has become the treatment of choice for extramedullary plasmacytoma. (1,2) However, the optimal treatment for radiation failures has not been delineated. (3,4) Extramedullary plasmacytoma presenting in the setting of chronic immunosuppression may have unique characteristics and might require its own treatment strategy. In this article, we describe our treatment of a chronically immunosuppressed patient with a nasal extramedullary plasmacytoma that failed to respond to multiple administrations of primary radiotherapy.

Case report

A 43-year-old man was referred to our department by an allergist for evaluation of a 9-month history of progressive unilateral nasal obstruction. His medical history was significant for rheumatoid arthritis, for which he had been taking long-term immunosuppression therapy. He also had a history of gout and obstructive sleep apnea.

Nasal endoscopy detected a pink polypoid mass in each of the patient's nasal cavities. On computed tomography (CT), the mass in the left naris was situated just anterior to the inferior turbinate, and the smaller mass in the right cavity had originated in the nasal floor (figure 1). No evidence of bone invasion was seen in either naris.

The patient underwent endoscopic excisional biopsy of the right mass for diagnosis. The pathologic analysis identified the lesion as a plasmacytoma (figure 2). The specimen stained positive for IgA and lambda light chains, and it was also positive for Epstein-Barr virus (EBV).

During the immediate postoperative period, the patient underwent hematologic and oncologic evaluations. The results of a bone marrow biopsy and a bone survey were both normal. Protein electrophoresis revealed that the IgA and IgG levels were normal, but the IgM kappa monoclonal immunoglobulin level was elevated. Urinalysis showed the kappa light chain Bence Jones protein.

In this patient, two separate entities were present simultaneously--an extramedullary IgA-secreting plasmacytoma and a monoclonal gammopathy of undetermined significance that had occurred as a result of the immunosuppression therapy for his rheumatoid arthritis. After our multidisciplinary tumor board reviewed this case, the patient was counseled to undergo treatment for the left-sided extramedullary plasmacytoma with stereotactic radiotherapy (54 Gy in 30 fractions). However, despite delivery of the full course of radiotherapy, the size of the left nasal plasmacytoma did not change. Three months after the completion of radiotherapy, it was removed endoscopically. Pathology confirmed the mass as a persistent plasmacytoma. Despite a prolonged healing time, the patient exhibited no evidence of persistence or recurrence following surgical excision at 42 months of follow-up.

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Discussion

Extramedullary plasmacytomas are monoclonal B-cell tumors that present as localized masses but do not meet the criteria for multiple myeloma because they do not involve the bone marrow. They account for approximately 3% of all plasma cell malignancies and less than 1% of all head and neck cancers. (1-3,5) More than 85% of extramedullary plasmacytomas are found in the upper aerodigestive tract. (2,5)

The most common symptoms at presentation are nasal discharge, nasal obstruction, and epistaxis. (2,5) The clinical features of extramedullary plasmacytoma include a median age at diagnosis of 55 years, a 3:1 male preponderance, and the presence of multiple lesions in about 10% of cases. (2) Progression to multiple myeloma occurs in less than 30% of cases. (2-4) When progression does occur, it is more common in patients with high-grade tumors. (1,5) Reported 5- and 10-year survival rates are approximately 80 and 67%, respectively. (2,5,6)

Treatment options for the potential cure of extramedullary plasmacytoma include surgery and radiation therapy. Radiation therapy is the more popular treatment because it is associated with excellent response rates (>90%) and low morbidity. (1,2) The British Society for Haematology has issued a set of guidelines for the diagnosis and treatment of extramedullary plasmacytoma. (2) The Society recommends initial radiation treatment with 40 Gy in 20 fractions with a 2-cm margin for tumors smaller than 5 cm, and 50 Gy in 25 fractions for larger tumors. Regional cervical lymph nodes should be irradiated only if they are directly involved or if there is a high risk of spread.