Multiple myeloma initially presenting with oral mucosal neoplasm and concurrent cast nephropathy: one case report with a literature view

• Gao Zi-qing, 
• Xiao Jie, 
• Bian Li-juan, 
• Xu Zhen-jian, 
• Li Zhen-lin, 
• Su Jia-nan, 
• Chen Peng-wei, 
• Wang Xiu-ju, 
• Yang Qiong-qiong, 
• Feng Min