Fine needle aspiration biopsy of hepatic lymphomas: cytomorphology and ancillary studies

The utility of fine needle aspiration biopsy (FNAB) for the diagnosis of epithelial hepatic neoplasms is now widely recognized. The liver may also play host to malignant nonepithelial stromal and lymphoreticular neoplasms, both metastatic and rarely primary. The cytomorphology of these hepatic tumors in aspiration smears is much less well known. In the current study, we examined FNAB material from hepatic lymphomas, including ancillary studies.

We collected 16 cases of lymphoma involving the liver and diagnosed by FNAB. The patients included seven women and nine men, with ages ranging from 34 to 84 years. Nine patients did not have a diagnosis of lymphoma prior to FNAB. In all cases, aspiration smears were stained by both Diff-Quik and Papanicolaou stain.

Dispersed, monomorphic lymphoid cells were usually numerous, whereas benign hepatocytes were scanty. In addition to the lymphoid appearances of individual cells, helpful clues included the presence of lymphoglandular bodies and the absence of true intercellular cohesion. There were 6 large cell, 3 immunoblastic, 2 small cell, 1 small cell cleaved, 2 mixed cell and 2 unclassified lymphomas in our FNAB series. Immunocytochemical studies were performed on 9 aspirated specimens, flow cytometry on 4 and gene rearrangement on 1. All these ancillary studies supported the cytomorphologic diagnosis of lymphoma, with approximately 90% classified as of B-cell lineage. All seven subsequent histologic examinations were confirmatory.

Other entities that must be considered in the FNAB differential diagnosis of hepatic lesions are nonlymphoreticular small cell neoplasms, inflammatory processes and sinusoidal hematopoietic cells. FNAB with ancillary studies can successfully establish the diagnosis of involvement of the liver by lymphoma.