to the editor: I read with great interest the article by Drs. Bazemore and Smucker, “Lymphadenopathy and Malignancy.”1 My colleagues and I recently reviewed the lymph node fine-needle aspiration (FNA) results on superficial and deeply seated lymph nodes from 439 patients with and without a previous diagnosis of malignancy.2 We found that patients in our series2 with a history of malignancy were more than twice as likely to show malignancy on lymph node FNA compared with those without such a history (87 percent versus 41 percent) in our series.2 This is an important detail to elicit in the history, supported by our data, but perhaps so obvious as to not have been mentioned more explicitly in the article.1
Also, the authors1 recommend excisional biopsy as the initial diagnostic procedure of choice for lymphadenopathy. Lymph node FNA has its limitations. Differentiating between malignant and reactive lymphoid proliferations has traditionally been the most challenging aspect of lymph node FNA cytology,3 especially with low-grade lymphoma. However, the routine use of ancillary studies such as flow cytometry in conjunction with cytologic findings improves diagnostic accuracy to the point that lymph node FNA is quite comparable to excisional biopsy in making that distinction. Immunocytochemistry, in situ hybridization, and polymerase chain reaction also can be performed on lymph node FNA specimens, and core or excisional biopsy can always be performed after lymph node FNA to confirm or further classify lymphoproliferative disorders for prognostication. For diagnosing metastatic malignancy, lymph node FNA is excellent, given that “foreign cells are easily visualized in [a] background of lymphoid elements.”4
Lymph node FNA is a cost-effective, valuable tool for the primary diagnosis of lymph nodes containing metastatic or hematologic malignancy, and for staging or monitoring of relapse in patients with known malignancy.5 Provisional diagnoses can be made rapidly in the clinic using the Diff-Quik staining method. Lymph node FNA is a safe and simple technique that can be used to sample lymph nodes in multiple sites or surgically inaccessible sites (under ultrasonography or computed tomography guidance), and in patients who might not tolerate a surgical biopsy procedure. Physicians can always proceed with excisional biopsy if indicated on lymph node FNA “triage.” Given these strengths, I was surprised that the authors did not more enthusiastically recommend lymph node FNA for evaluating lymphadenopathy.
editor’s note: This letter was sent to the authors of “Lymphadenopathy and Malignancy,” who declined to reply.