The Etiologic Landscape of Lymphoproliferation in Childhood: Proposal for a Diagnostic Approach Exploring from Infections to Inborn Errors of Immunity and Metabolic Diseases

Lymphoproliferation is defined by lymphadenopathy, splenomegaly, hepatomegaly, or lymphocytic organ and tissue infiltration. The most common etiologies of lymphoproliferation are represented by infectious diseases and lymphoid malignancies. However, it is increasingly recognized that lymphoproliferative features can be the presenting sign of rare conditions, including inborn errors of immunity (IEI) and inborn errors of metabolism (IEM). Among IEI, lymphoproliferation is frequently observed in autoimmune lymphoproliferative syndrome (ALPS) and related disorders, common variable immunodeficiency (CVID), activated phosphoinositide 3-kinase δ syndrome, and Epstein-Barr virus (EBV)-related disorders. Gaucher disease and Niemann-Pick disease are the most common IEMs that can present with isolated lymphoproliferative features. Notably, other rare conditions, such as sarcoidosis, Castleman disease, systemic autoimmune diseases, and autoinflammatory disorders, should be considered in the differential diagnosis of patients with persistent lymphoproliferation when infectious and malignant diseases have been reasonably ruled out. The clinical features of lymphoproliferative diseases, as well as the associated clinical findings and data deriving from imaging and first-level laboratory investigations, could significantly help in providing the correct diagnostic suspicion for the underlying etiology. This paper reviews the most relevant diseases associated with lymphoproliferation, including infectious diseases, hematological malignancies, IEI, and IEM. Moreover, some practical indications to orient the initial diagnostic process are provided, and two diagnostic algorithms are proposed for the first-level assessment and the approach to persistent lymphoproliferation, respectively.

The diagnostic value and safety of modified needle aspiration biopsy for superficial lymphadenectasis

Objective

To explore the safety and diagnostic value of modified needle aspiration biopsy for superficial enlarged lymph nodes.

Methods

A total of 88 patients with unknown diagnosis of superficial lymphadenopathy in our hospital (Wuxi Fifth People's Hospital) from January 2018 to July 2021 were recruited and then divided into two groups using the simple random grouping method. The study group included 48 patients who were punctured via modified needle aspiration biopsy, while the control group included 40 patients who were punctured via core needle biopsy (CNB) and had a better clinical evaluation. A BARD® automatic biopsy gun with a 18 G needle was used to puncture any enlarged lymph nodes, and specimens were obtained for pathological examination. The diagnostic positive rate of the two puncture methods was then compared and the complications involved in the two methods were observed.

Results

The positive rate of definite pathological diagnosis was 79.2% (38/48) in the study group and 82.5% (33/40) in the control group. Both groups had similar diagnostic positive rates regarding tuberculosis and metastatic tumours in the lymph nodes (P > 0.05). Only slight bleeding was observed during the operations using the two puncture methods, with the bleeding rate of the study group 20.8% and that of the control group 15.0%, and the difference was not statistically significant (P > 0.05). No other complications were observed across both groups. Among the 48 patients with enlarged lymph nodes in the study group, there was no difference in the positive rate of diagnosis between enlarged lymph nodes larger than 20 mm and those smaller than 20 mm in the pathological, bacterial culture and cytology examinations (P > 0.05). The sensitivity, specificity, positive predictive values and negative prediction values of the improved lymph node lesions were 83.3%, 100%, 100% and 90.9%, respectively.

Conclusion

The diagnostic efficacy and safety of modified needle aspiration biopsy in superficial swollen lymph nodes are equivalent to those of CNB, but the former is a more economical, simple and practical method for clinical settings and one that could be popularised in primary hospitals.

Prevalence and Predictors of Bacterial Contamination in Excisional Lymph Node Biopsies: Implications for Diagnosis and Management

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.