The incidence of imaging findings, and the distribution of skeletal lymphoma in a consecutive patient population seen over 5 years.

OBJECTIVE: To determine the imaging incidence, distribution, and prognosis of primary and secondary osseous lymphoma from a consecutive, single-institution patient population seen over a 5-year period. DESIGN AND PATIENTS: Of 1098 newly diagnosed consecutively seen patients with lymphoma between 1996 and 2000, 975 comprised the study group. From the electronic medical records and imaging studies, age, gender, date of diagnosis of lymphoma, bone involvement, location in bone, multifocality in bone, histopathologic type of the lesion and patient survival were recorded. Primary lymphoma of bone was defined as osseous disease with or without regional node involvement and no evidence of systemic disease for 6 months. Secondary osseous lymphoma was considered present when osseous lymphoma was associated with systemic disease or the appearance of systemic disease within 6 months of osseous disease.
RESULTS: Ninety-eight patients had osseous lymphoma (10%, 95% confidence interval [CI] 8.2, 11.9). Ages ranged from 9 to 92 years (mean 54) and gender 6:4 (M:F). Ten patients (1%) had primary lymphoma of bone. Eighty-eight patients (9%) had secondary lymphoma of bone. The vertebral column was the favored site for secondary osseous lymphoma. At 5 years, there were no deaths in the primary osseous lymphoma group and a 51% mortality rate in the secondary osseous lymphoma group.
CONCLUSIONS: Primary lymphoma of bone remains a rare primary malignancy, favors the appendicular skeleton, and has a significantly better 5-year prognosis than secondary lymphoma of bone.