To the Editor:
Extramedullary plasmacytoma (EMP) is a rare plasma cell neoplasm characterized by a monoclonal proliferation of plasma cells that arise outside the bone marrow. It occurs most commonly during the fourth through to seventh decades of life, more commonly affecting men than women. In a large cohort of 1003 patients with multiple myeloma, only 13% had EMP, although the incidence of EMP has increased over the years, likely owing to widespread use of advanced imaging techniques such as computed tomography (CT) and magnetic resonant imaging scanning.1 EMPs constitute 3% of plasma cell tumors and are most frequently present in the submucosal tissue of upper airway, such as the head and neck area, as these sites are rich in lymphoid tissue.1 EMPs arising in the tracheobronchial tree is rare and represents 3% of tracheal tumors.1 We describe a case of an obstructive right endobronchial mass diagnosed as plasmacytoma in a patient with no preexisting plasma cell neoplasm.
An 80-year-old woman with a recent diagnosis of asthma presented with a 6-month history of cough and shortness of breath. Auscultation showed a prolonged expiratory phase and decreased breath sounds over the right lung field. Routine laboratory testing was unremarkable. Pulmonary function testing showed severe airflow obstruction [forced expiratory volume (fev)1=0.62 L (37%), fvc=1.02 L (46%), forced vital capacity (fvc)1/fvc=53%] with significant bronchodilator response. Chest CT scan revealed a 1.5×2.6 cm partially calcified endobronchial mass invading the right main stem bronchus (Fig. 1A). During rigid bronchoscopy, a large endobronchial yellow-tinged mass with smooth surface completely obliterating the lumen of the right main bronchus was appreciated (Fig. 1B).
After tumor debridement patency of the right main stem bronchus was restored with residual tumor limited to right upper lobe bronchus. Pathology showed sheets of plasma cells mixed with eosinophilic amorphous material. Immunoperoxidase staining revealed CD138-positive monoclonal plasma cells based on λ light-chain expression. Congo red staining showed apple-green birefringent material under polarized light indicative of amyloid (Figs. 2A–D). Systemic work up for amyloidosis and multiple myeloma, including serum electrophoresis, skeletal survey and bone marrow aspiration, was negative. Diagnosis of EMP with amyloid deposition was established. Given residual disease in right upper lobe, external beam radiation was recommended. Surgery was not pursued due to patient’s advanced age and compromised pulmonary function. Six months after diagnosis she is doing well with no respiratory complaints and with normalization of pulmonary lung function [fev1=1.16 L (94%) and fvc=2.11 L (131%)]. We attribute the rapid improvement in her postprocedure lung function to resolution of endobronchial obstruction and subsequent restoration of airway patency.
Patients with EMP involving the tracheobronchial tree usually present with nonspecific respiratory symptoms related to bronchial obstruction. Chest CT often reveals a partially calcified endobronchial mass and a tan-colored tumor is frequently seen on bronchoscopy. Yellowish discoloration has been described in cases of endobronchial amyloidosis due to the amyloid deposition. Large biopsy samples obtained during bronchoscopy are often required to establish a diagnosis. Histologic and immunophenotypic examination shows a proliferation of monotypic plasma cell proliferation that is positive for CD138. Tracheobronchial plasmacytomas have been hypothesized to arise from extramedullary hematopoiesis in the cartilaginous part of the tracheal wall. Amyloid deposition is rarely associated with EMP. In one of the largest case series of tracheobronchial EMPs, amyloid deposition was reported in only 2 of 18 cases.1 The majority of solitary EMP cases with κ light-chain deposition are associated with multiple myeloma.2 Kidneys are most often affected by light-chain deposition, although the true incidence is unknown as normal serum and urine electrophoresis do not exclude light-chain deposition in these organs. Although EMPs involving the tracheobronchial site have been reported, our case is unusual in that our patient’s tumor was characterized by amyloid deposition without systemic involvement.
Given rarity of EMP and lack of guidelines, optimal treatment remains controversial. In addition to endobronchial debulking therapy, treatment options include surgery, radiotherapy, or both. Endoscopic resection alone is unlikely to provide adequate local control, creating a potential for persistent/recurrent disease. The choice of treatment modality is based on location, extent of disease and patient’s operative candidacy. Radiotherapy using 35 to 50 Gy has been used for local control if surgical resection is not feasible or if persistent disease is present.3 Systemic chemotherapy is typically reserved for widespread disease. It is important to exclude systemic amyloidosis and multiple myeloma before offering treatment for local disease.
The prognosis is comforting: around 60% of patients with plasmacytoma of upper aerodigestive tract present complete remission, 22% have local recurrence, and only 16% show progression to multiple myeloma.4 Median time for progression is 13 months, although reports of conversion up to 13 years after initial diagnosis have been described.4 Hence, long-term follow-up after initial diagnosis is necessary. Long-term prognosis is good with no reported mortalities after an 8-year follow-up.4 There is limited literature on risk factors for local or systemic recurrence of EMP. A study by Sheth et al5 showed the association of p53, CD56, and MIB-1 expression in extramedullary biopsies of multiple myeloma patients with progression to extramedullary myeloma. We are not aware of any identifiable risk factors for local or systemic recurrence of EMP in patients without multiple myeloma.
Michael Oriakhi, MD*†
Enrique Ortiz-Diaz, MD*†
Margaret Olibrice, MD*†
Meena Ahluwalia, MD‡
Amy Chadburn, MD§
Eugene Shostak, MD∥
*Department of Internal Medicine Division of Pulmonary
‡Department of Internal Medicine Division of Hematology and Medical Oncology Harlem Hospital Center
§Department of Pathology and Laboratory Medicine
∥Department of Cardiothoracic Surgery New York Presbyterian Hospital, Weill Cornell Medical, Center, New York, NY
†Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine Methodist Hospital-Willowbrook Houston TX
1. Durris N, Rosnet G, Clemenson A, et al. Characteristics and management of tracheobronchial extramedullary plasmacytomas. J Bronchol. 2002;9:186–192.
2. Piard F, Yaziji N, Jarry O, et al. Solitary plasmacytoma of the lung with light chain extracellular deposits: a case report and review of the literature. Histopathology. 1998;32:356–361.
3. Jyothirmayi R, Gangadharan V, Nair M, et al. Radiotherapy in the treatment of solitary plasmacytoma. Br J Radiol. 1997;70:511–516.
4. Hotz MA, Schwaab G, Bosq J, et al. Extramedullary solitary plasmacytoma of the head and neck. Ann Otol Rhinol Laryngol. 1999;108:495–500.
5. Sheth N, Eung J, Chang H. p53 nuclear accumulation is associated with extramedullary progression of multiple myeloma. Leuk Res. 2009;33:1357–1360.