TY - JOUR
T1 - Prevalence and Predictors of Bacterial Contamination in Excisional Lymph Node Biopsies
T2 - Implications for Diagnosis and Management
AU - Hergott, Christopher B.
AU - Craig, Jeffrey W.
AU - Hornick, Jason L.
AU - Weinberg, Olga K.
N1 - Publisher Copyright:
© 2021 Lippincott Williams and Wilkins. All rights reserved.
PY - 2021/9
Y1 - 2021/9
N2 - Routine tissue handling exposes lymph node specimens to microbial contamination that can confound microbiological culture results and interfere with diagnosis. The scope and impact of this problem remain poorly understood. We combined over 13 years of lymph node pathology, culture data, and patient records to define the prevalence, predisposing factors, microbiology, and clinical management of false-positive lymph node cultures at a large academic medical center. Nearly one third (31.9%) of 216 cultured lymph nodes yielded bacterial growth. Approximately 90% of positive bacterial cultures grew 1 of 2 common skin-resident taxa - coagulase-negative Staphylococcus and Cutibacterium acnes - with well-documented predispositions for contamination in other clinical settings. Lymph nodes excised from axillary, cervical, and inguinal regions yielded higher positive culture rates than nodes excised from the mediastinum, suggesting proximity to the skin surface may increase contamination risk. Accordingly, cultures from thoracoscopic pulmonary resections displayed contamination rates over 5-fold lower than those from percutaneously accessed lymph nodes. Lymph nodal tissue allocated for culture in the operating room yielded unexpectedly high contamination rates, significantly higher than cultures sent from the frozen section processing area. A significant minority of contamination events were noted in the clinical record and prompted antibiotic therapy on multiple occasions. Collectively, our results illuminate the risk factors contributing to bacterial contamination and argue that routine lymph node bacterial cultures provide minimal clinical benefit for adult patients. This widespread bacterial contamination also warrants cautious implementation of increasingly sensitive molecular microbiology tools for excised tissues.
AB - Routine tissue handling exposes lymph node specimens to microbial contamination that can confound microbiological culture results and interfere with diagnosis. The scope and impact of this problem remain poorly understood. We combined over 13 years of lymph node pathology, culture data, and patient records to define the prevalence, predisposing factors, microbiology, and clinical management of false-positive lymph node cultures at a large academic medical center. Nearly one third (31.9%) of 216 cultured lymph nodes yielded bacterial growth. Approximately 90% of positive bacterial cultures grew 1 of 2 common skin-resident taxa - coagulase-negative Staphylococcus and Cutibacterium acnes - with well-documented predispositions for contamination in other clinical settings. Lymph nodes excised from axillary, cervical, and inguinal regions yielded higher positive culture rates than nodes excised from the mediastinum, suggesting proximity to the skin surface may increase contamination risk. Accordingly, cultures from thoracoscopic pulmonary resections displayed contamination rates over 5-fold lower than those from percutaneously accessed lymph nodes. Lymph nodal tissue allocated for culture in the operating room yielded unexpectedly high contamination rates, significantly higher than cultures sent from the frozen section processing area. A significant minority of contamination events were noted in the clinical record and prompted antibiotic therapy on multiple occasions. Collectively, our results illuminate the risk factors contributing to bacterial contamination and argue that routine lymph node bacterial cultures provide minimal clinical benefit for adult patients. This widespread bacterial contamination also warrants cautious implementation of increasingly sensitive molecular microbiology tools for excised tissues.
KW - contamination
KW - culture
KW - lymph node
KW - microbiology
KW - surgical pathology
UR - http://www.scopus.com/inward/record.url?scp=85113743005&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85113743005&partnerID=8YFLogxK
U2 - 10.1097/PAS.0000000000001699
DO - 10.1097/PAS.0000000000001699
M3 - Article
C2 - 34232607
AN - SCOPUS:85113743005
SN - 0147-5185
VL - 45
SP - 1235
EP - 1244
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
IS - 9
ER -