Yield of endoscopic ultrasound-guided fine needle aspiration for subcentimetric lymph nodes: A comparison to larger...

Subcentimetric (defined as <1 cm at short axis) lymph nodes are considered benign and there is limited literature on the results of fine needle aspiration (FNA) of these nodes.

Endoscopic ultrasound (EUS) guided FNA was done on 189 lymph nodes in 166 patients with pyrexia of unknown origin (n = 113) or malignancy (n = 53). Subcentimetric lymph nodes (Group A) were compared to nodes with short axis diameter ≥1 cm (Group B). Data are shown as number, percentage, and median (25-75 interquartile range).

There was no significant difference between Group A and Group B regarding site of lymph nodes (mediastinal in 73.6 and 72.5%, abdominal in 26.3 vs. 27.4%), number of slides (median 14 vs. 15), needle passes (median 2), and needle used (22 G needle in 85.5% vs. 69.9%). Group A had significantly lesser long axis diameter (1.5 [1.2-2] vs. 2.1 [1.6-2.9] cm) and short axis diameter (0.7 [0.6-0.8) vs. 1.4 [1.1-1.6] cm). A diagnosis (pathologic or reactive) could not be made in 2 (2.6%) and 11 (9.7%) lymph nodes in Group A and Group B, respectively (P = 0.078), due to inadequate material. Respective diagnoses in Group A and Group B were reactive lymphadenopathy (51.3% vs. 18.5%, P = 0.000), granulomatous lymphadenopathy (34.2% vs. 53%, P = 0.011), and malignancy (11.8% vs. 18.5%, P = 0.231). The lymph nodes with granulomatous and malignant change were significantly larger and had higher chances of having sharply demarcated borders as compared to reactive nodes.

EUS-guided FNA of subcentimetric lymph nodes have comparable results to larger nodes. Almost half of the subcentimetric lymph nodes are pathologic.