High-resolution ultrasonography, US-guided fine-needle aspiration cytology and flow cytometry in the diagnosis of recurrent lymphoma

Background: High-resolution ultrasonography (US) is the imaging technique usually used in differentiating between benign/reactive enlarged lymph nodes from malignancy (e.g. node metastasis, lymphoma), and US-guided fine-needle aspiration cytology (FNAC) and flow cytometry (FC) significantly improve US accuracy. The aim of this study was to evaluate the usefulness of high-resolution US, US-guided FNAC and FC together in the diagnosis of recurrent lymphoma. Patients and Methods: One-hundred and eight consecutive patients with suspected recurrent lymphoma underwent neck US and US-guided FNAC with FC in a single session. There were 63 women (58.3%) and 45 men (41.7%) with a median age of 54 years (range 18-77 years). Inadequate or unclear specimen requiring repeated FNAC were excluded. Large nodes (>15 mm), hypoechoic echotexiture, round shape, and well-defined borders represented US sign of malignancy. The cells were harvested from the samples obtained for FC examination, which was performed by using an automatic t cytofluorometer, gated by using the forward- and side-scatter histograms, and the samples were stained for the panel of antibodies, including CD5, CD10, CD19, CD23, Kappa, Lambda, Mu, and CD45. All patients underwent surgical excision and subsequent histopathological examination of the removed lymph node. Results: Final pathology showed the presence of a primary or recurrent lymphoma in 64 (59.3%) patients, and a benign disease in 44 (40.7%) patients. The results are reported in the Table below. The sensitivity ranged from 84.4% to 76.5% (p=0.28) and the specificity from 86.4% to 75.5% (p=0.11), while the accuracy did not differ (80.6%). The combination of US, FNAC and FC reached 87.5% sensitivity, 88.9% specificity, and 89.0% accuracy. The area under the receiver operating characteristic (ROC) curve was 0.72 (95% CI 0.63-0.81). Conclusions: All patients with suspicious lymphoadenopathy on US should undergo US-guided FNAC, but FC gives a low improvement (p=NS) to results.