Primary Lymphoma of Bone

Abstract

Lymphoma of bone is not uncommon, accounting for 7% of primary bone malignancies and 5% of extranodal lymphomatous involvement.1 Osseous lymphoma is divided into four groups based on extent of disease: (1) a solitary osseous lesion, (2) multifocal osseous involvement without soft tissue or nodal involvement, (3) simultaneous osseous and nodal/soft tissue involvement, and (4) osseous involvement presenting more than 6 months after an established diagnosis of lymphoma.1 Primary bone lymphoma is defined by the World Health Organization as a malignant lymphoid neoplasm of bone, either at a single bone site with or without regional lymph node involvement, or at multiple bone sites without visceral or lymph node involvement. The majority of cases are diffuse large B-cell lymphoma, but other subtypes of non-Hodgkin lymphoma also are seen. Primary Hodgkin lymphoma of bone has been reported; however, extranodal manifestations of Hodgkin lymphoma of any type are extremely rare. Primary bone lymphoma is rare in children younger than 10 years of age, as are most primary bone tumors. Primary bone lymphoma usually is seen in the second to eighth decades; most cases, however, are found in young adults (late teens to early 30s), with a male-to-female ratio of about 2:1.