The American College of Radiology Incidental Findings Committee Recommendations for Management of Incidental Lymph Nodes: A Single-Center Evaluation.
To assess the American College of Radiology Incidental Findings Committee's (ACR-IFC) recommendations for defining and following up abnormal incidental abdominopelvic lymph nodes.



A total of 59 lymph nodes satisfying ACR-IFC criteria as incidental (no malignancy or lymphoproliferative disorder) and with sufficient follow-up to classify as benign (biopsy, decreased size, ≥12-month stability) or malignant (biopsy, detection of primary malignancy combined with either fluorodeoxyglucose hyperactivity or increase in size of the node) were included. Two radiologists independently assessed nodes for suspicious features by ACR-IFC criteria (round with indistinct hilum, hypervascularity, necrosis, cluster ≥3 nodes, cluster ≥2 nodes in ≥2 stations, size ≥1 cm in retroperitoneum). Outcomes were assessed with attention to ACR-IFC's recommendation for initial 3-month follow-up.



A total of 8.5% of nodes were malignant; 91.5% were benign. Two of six malignant nodes were stable at 3 to <6-month follow-up before diagnosis; diagnosis of four of five malignant nodes was facilitated by later development of non-nodal sites of tumor. A total of 13, 5, 8, and 9 nodes were deemed benign given a decrease at <3 months, 3-5 months, 6-11 months, or ≥12 months of follow-up. No ACR-IFC feature differentiated benign and malignant nodes (P = 0.164-1.0). A cluster ≥3 nodes was present in 88.1%-93.2% of nodes. A total of 96.6%-98.3% had ≥1 suspicious feature for both readers. Necrosis and hypervascularity were not identified in any node.



ACR-IFC imaging features overwhelmingly classified incidental nodes as abnormal, although did not differentiate benign and malignant nodes. Nodes stable at the ACR-IFC's advised initial 3-month follow-up were occasionally proven malignant or decreased on further imaging. Refinement of imaging criteria to define nodes of particularly high risk, integrated with other clinical criteria, may help optimize the follow-up of incidental abdominopelvic lymph nodes.
Department of Radiology, NYU Langone Medical Center, New York University School of Medicine, 660 First Avenue, New York, NY 10016. Electronic address: paul.smereka@nyumc.org.
Paul
P
Smereka
Department of Radiology, NYU Langone Medical Center, New York University School of Medicine, 660 First Avenue, New York, NY 10016.
Ankur M
AM
Doshi
Department of Radiology, NYU Langone Medical Center, New York University School of Medicine, 660 First Avenue, New York, NY 10016.
Justin M
JM
Ream
Department of Radiology, NYU Langone Medical Center, New York University School of Medicine, 660 First Avenue, New York, NY 10016.
Andrew B
AB
Rosenkrantz
D000008:Abdominal Neoplasms / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D061705:Image-Guided Biopsy / Q000592:standards; D033162:Incidental Findings; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000592:standards*; D017410:Practice Guidelines as Topic; D011871:Radiology; D014057:Tomography, X-Ray Computed / Q000592:standards*; D014481:United States
CT; Lymph nodes; abdominal imaging; incidental findings