Utility of CT-Guided Biopsy of Suspicious Skeletal Lesions in Patients With Known Primary Malignancies

Patients with a known primary malignancy and one or more suspicious skeletal lesions are often assumed to have skeletal involvement by the known malignancy. We set out to determine how often one would be correct in making this assumption. All CT-guided bone biopsies performed at our institution between January 2006 and January 2009 in patients with a history of a single biopsy-proven malignancy were retrospectively reviewed. Pathology results were assigned to one of three outcomes: skeletal involvement by known malignancy, newly diagnosed malignancy, or no malignancy identified. Patients categorized as no malignancy identified required repeat biopsy or stability on follow-up imaging for confirmation. Of 104 patients with a known primary malignancy, 11 were excluded. Of the 93 included patients, there was skeletal involvement by the known malignancy in 82 (88%), a newly diagnosed malignancy in seven (8%), and no malignancy identified in four (4%). Biopsy of a suspicious skeletal lesion in a patient with a solitary known malignancy reveals a newly diagnosed malignancy or no evidence of malignancy in 12% of patients, emphasizing the importance of biopsy.