Solitary extramedullary plasmacytoma

Solitary Plasmacytoma in the Setting of Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is an intriguing disorder characterized by the accumulation of specialized dendritic cells called Langerhans cells in several diverse tissues and body sites. It has been cited in numerous case reports to be associated with a wide variety of malignant neoplasms. Although many hypotheses have been suggested, the basis for such associations remains essentially unknown. We describe another association here that to our knowledge has not been reported thus far: a solitary plasmacytoma occurring at a site of previous involvement by LCH. This constitutes a new addition to the now fairly lengthy list of malignant neoplasms that have been reported to occur in the setting of LCH. The possible reasons for such an association are discussed along with a brief review of LCH.

Recurrent primary plasmacytoma of the eyelid with rapid regional metastasis

In this case, originally reported as primary eyelid plasmacytoma, the tumor recurred on the same eyelid within 2 years of surgery. No plasma cell infiltration was observed at bone marrow biopsy. No serum or urinary monoclonal component was detected at immunofixation. Histology and immunohistochemistry confirmed plasma cell infiltration. Tumor cell clonality was determined by immunohistological staining; cells were positive for kappa light chain like the first eyelid tumor. Surgery was followed by radiotherapy. Twenty months later, biopsy of one enlarged right cervical lymph node showed massive diffuse infiltration of atypical plasma cells (CD20(-), CD79a(+), CD138(+), MUM1/IRF4(+)). Given the rapid diffusion to lymph nodes and the appearance of the monoclonal component, the lymph node was removed surgically. No adjuvant chemotherapy was given. Unexpectedly, the serum monoclonal component normalized. No plasma cell infiltration was observed at bone marrow biopsy. As this case might be a particularly slow-progressing extra-medullary plasmacytoma, this study recommends closely monitored follow-ups so that the aggressive form can be treated in time.

Clinical course of solitary extramedullary plasmacytoma

BACKGROUND AND PURPOSE

Solitary extramedullary plasmacytoma (EMP) represents a rare category of malignant disease on which there are limited data in regard to diagnosis, staging and natural history. This study attempted to clarify the clinical course of solitary extramedullary plasmacytoma after radiation or surgical therapy given with curative intent.

MATERIALS AND METHODS

The diagnosis was based on a mass of clonal plasma cells separate from bone or bone marrow without evidence of occult disease elsewhere. Between 1963 and 1996, 22 previously untreated patients with an EMP were diagnosed. Disease presented in the head or neck in 86%, usually in the nasal cavity (NC) or maxillary sinus (MS), and in these areas local bone destruction was found in 10 of 11 patients. Among all patients, serum myeloma protein was present in three patients (14%) and Bence Jones protein alone was found in two patients (9%). Radiation therapy was the sole treatment for 18 of 22 patients, and the median radiotherapy dose was 50 Gy (range, 40-60 Gy); five of seven patients with an EMP of oral cavity (OC), oropharynx (OP), nasopharynx (NP), parotid or larynx also received elective neck irradiation. Two patients underwent surgery plus postoperative irradiation of a plasmacytoma of the sigmoid colon or pleura, and two patients had resection alone of a plasmacytoma of the colon or cervical lymph node.

RESULTS

Local control was achieved in 21 of 22 patients (95%), and disease never recurred in regional nodes. Disappearance of myeloma protein occurred in three of five patients with an evaluable abnormality. Multiple myeloma developed in seven patients (32%), all within 5 years. The 5-year rate of freedom from progression to multiple myeloma was 56% and the median survival was 9.5 years.

CONCLUSION

Radiation therapy achieved excellent locoregional control of EMP with an approximate cure fraction of 50%.