Image-guided biopsy of suspicious lymph nodes in patients with known primary malignancies.

ABSTRACT

PURPOSE: To determine how often abdominal, pelvic, and inguinal lymphadenopathy in patients with a known malignancy arises from a second primary cancer or from benign causes, rather than from the cancer already known. MATERIALS AND METHODS: A total of 196 patients with a history of a single biopsy-proven malignancy underwent image-guided abdominal or pelvic lymph node (LN) biopsies between January 2000 and January 2005. Three patients were excluded. The medical records and imaging of the remaining 193 patients were reviewed. Pathologic results were assigned to one of three outcomes: LN involvement by known malignancy, newly diagnosed malignancy, or no malignancy identified. Patients in whom malignancy was not identified required repeat biopsy or stability or reduction in size of LN on follow-up imaging for confirmation while not receiving treatment. RESULTS: Of the 193 included biopsies, there was LN involvement by the known malignancy in 148 (76.7%; 95% CI, 70.1%-82.5%), a newly diagnosed malignancy in 19 (9.8%; 95% CI, 6.0%-14.9%), and no malignancy identified in 26 (13.5%; 95% CI, 9.0%-19.1%). CONCLUSIONS: Biopsy of a suspicious abdominal or pelvic LN in patients with known malignancy reveals a newly diagnosed malignancy or no evidence of malignancy in 23% of cases, emphasizing the importance of biopsy.