LAUSR

Plasma cell neoplasms arising outside of bone are known as extraosseous/extramedullary plasmacytoma. Although they constitute about 1% of all plasma cell neoplasms, updated epidemiological data are lacking in the current literature. Here, we have analyzed the incidence provided by the national cancer institute (SEER database) from 1975 – 2016 to shed light on the incidence, demographics, and survival of extraosseous plasma cell neoplasms. We selected all cases of plasma cell neoplasms from the data provided by the national cancer institute (SEER database) from 1975 – 2016. We excluded all cases designated with the primary site as bone or bone marrow. We analyzed the data using SPSS statistics 20. We compared overall survival among different demographic groups and performed the log-rank test to see differences in overall survival. A total of 731 cases were found with extraosseous plasmacytoma in the United States with a male: female ratio of 1.85:1. The age range was from 9 to 92 years with a median age of 61. Younger age of diagnosis was associated with better overall survival. Overall survival was not significantly different between males and females (p = 0.4). The majority of the patients were Caucasian and overall survival was significantly better in this group (p = 0.028). Consistent with the current literature, the primary sites of the majority of cases were head and neck (44.5%) and soft tissue (15.7%). Overall survival was significantly different between different primary sites (p < 0.05) with primary sites of soft tissue, thorax (including lung, mediastinum, and pleura), and CNS showing particularly poor survival. Our results suggest that the prognosis of extraosseous plasma cell neoplasm is site-specific and a better understanding of tumor microenvironment in plasmacytoma arising in different primary sites is warranted.