Plasmacytoma is a rare malignant disease based of 
differentiated plasmatic B cells, which occurs also in the head and 
neck region. It rarely involves the mandible. The authors present 
an unusual evaluation of this pathology through a clinical case of 
a 45 year old patient diagnosed with solitaty plasmocytoma in the 
Temporomandibular Joint (TMJ) region. The solitary tumor was 
located in the area between the muscular and articular process of 
the left side of the mandible. Resection of the tumour and 
articular process was performed under general anesthesia. 
Histopathology revealed sheets of plasma cells with cartwheel 
appearance and expansive bone trabecula – plasmacytoma of the 
mandible. Complementary treatment was performed by four 
cycles of systemic chemotherapy. The tumor recurrence was 
diagnosed after three year during control MRI examination. The 
patient underwent autologous cell transplantation from his brother 
without any surgical treatment. In the three-year follow up the 
patient didn’t show local progression of the tumour. The 
oncologist did not recommend another surgery. Five year post 
operation and chemotherapy patient died for gastrointestinal 
complication.