Radiotherapy-Resistant Solitary Bone Plasmacytoma of the Clavicle

Abstract Solitary bone plasmacytoma of the clavicle is an extremely rare tumor, with an incidence of approximately 0.05% among the primary tumors of the skeleton, defying a challenging diagnostic and therapeutic problem. The absence of particular clinical signs and laboratory tests and the abated sensitivity of modern imagination to differentiate the benign or malignant characteristics of an osteolytic lesion of the distal clavicle impeded a definite diagnosis, which can usually be obtained only after an open biopsy of the lesion. The presented case is distinctive, as it refers to a plasmacytoma of the distal end of the clavicle, which expressed unexplained resistance to both the administrated radiotherapy and chemotherapy. The therapeutic quandary finally resolved after the surgical resection of the entire lesion, leaving the patient free of plasma cell disease 37 months after the initial diagnosis.