Diagnosis of lymphoma by image-guided needle biopsies: fine needle aspiration biopsy, core biopsy or both?

OBJECTIVE: To determine whether or not concurrent core biopsy adds to results obtained from image-guided fine needle aspiration biopsy (FNAB) in cases of lymphoma.

STUDY DESIGN: Twenty-eight FNABs of lymphomas with adjuvant flow cytometry (FC) and concurrent core biopsy were evaluated retrospectively. In each case, completeness of diagnosis by FNAB, including phenotyping and grading, where appropriate, was reviewed. The contribution of core biopsy to the diagnosis in cases where FNAB did not render a complete diagnosis was assessed. Prognostic information not available from the FNAB but obtained from the core biopsy was also evaluated.

RESULTS: FNAB with adjuvant FC gave a complete diagnosis, including phenotype and grade, where applicable, in 23 of 28 cases (82%). Core biopsy added to the diagnosis in 3 cases. In 1 case, large B-cell lymphoma was diagnosed on core biopsy when FNAB was unsatisfactory. In the other 2 cases, grade of follicle center cell lymphoma was higher on core biopsy than on FNAB. The addition of the information obtained by core biopsy to that obtained by FNAB raised the diagnostic accuracy to 93%. Core biopsy was used to assess nodularity, which could not be determined on FNAB. Core biopsy was also used to assess prognostic markers by immunohistochemistry (Ki-67 and p53); they were not available with FC. This was done in 11 cases when requested by the oncologist.

CONCLUSION: FNAB with adjuvant FC is a useful technique for diagnosing and subtyping lymphomas. However, diagnosis and subclassification are often insufficient. Core biopsy material provides opportunity for obtaining additional diagnostic and prognostic information that may not be easily derived from the FNAB. This allows optimal treatment planning in patients for whom excisional biopsy is contraindicated.