Spectrum of [18F]FDG-PET/CT Findings in Benign Lymph Node Pathology

Diffuse lymphadenopathy has a long differential diagnosis that includes both malignant and benign causes. As part of the lymphadenopathy work-up, many patients undergo [18F]FDG-PET/CT for purposes of ruling out malignancy. FDG-avid lymph nodes, however, are not specific for malignancy. This review will illustrate the spectrum of nodal findings on FDG-PET/CT with correlation to other cross-sectional imaging and clinical history in patients with representative infectious, inflammatory, and benign lymphoproliferative disorders. These findings are important for the nuclear medicine radiologist to understand, as they can represent common pitfalls in the work-up of lymphadenopathy. While FDG-PET/CT may be limited in ascertaining a definitive diagnosis in a disease process as the cause of lymphadenopathy, it can help to narrow this differential and rule out certain diseases in the correct clinical context.

Castleman Disease In Children: Diagnosis and Treatment

Background: We describe the experiences in diagnosis and results of treatment in pediatric Castleman disease. Method: Serial case reports. Result: From 2016 to 2019, we had 7 cases of pediatric Castleman disease: 3 boys and 4 girl. The median age at diagnosis was 147 months (121-173 months). Clinical manifestations were found in five cases. They were all unicentric Castleman disease (6 abdominal mass, one left infraclavicular mass). All patients were operated with postoperative period uneventful. The median time of postoperative follow up was 22.7 months (11-53 months) with no signs of relapse. Conclusions: Pediatric Castleman disease is a rare benign lymph node hyperplasia, it can be localised or disseminated. Operation is the treatment of choice for localised Castleman disease.

Benign lymph node microenvironment is associated with response to immunotherapy

Introduction Benign lymph nodes have been considered the hubs of immune surveillance in cancer patients. The microenvironment of these lymphoid tissues can be immune suppressed, hence allowing for tumor progression. Understanding the spectrum of benign findings in bystander lymph nodes in immune checkpoint blockade therapy could prove to be key to understanding the mechanism and assessing treatment response. Methods Benign lymph nodes and spleen were evaluated from patients treated with immunotherapy who subsequently received postmortem examination. We used quantitative immunofluorescence (QIF) to assess tumor infiltrating lymphocytes (TIL) and macrophage marker expression and characterized activation status using a novel multiplexed QIF assay including CD3, GranzymeB, and Ki67. We performed immunohistochemistry to correlate results of QIF. Results Benign lymph nodes from non-responders to immunotherapy showed significantly higher expression of cytotoxic markers and proliferation index (Ki67) in T cells compared to responders. Higher expression of PD-L1 in macrophages was also observed. There was no significant difference in CD3+ expression, but higher levels of CD8+ T cells as well as CD20+ B cells were seen in lymph nodes of non-responders. No significant differences were seen between responder and non-responder splenic tissue. Findings were supported by traditional immunostaining methods. Conclusions While most studies in biomarkers for immunotherapy focus on tumor microenvironment, we show that benign lymph node microenvironment may predict response to immunotherapy. In responding patients, bystander lymph nodes appear to have been mobilized, resulting in reduced cytotoxic T cells. Conversely, patients whose disease progressed on immunotherapy demonstrate higher levels of macrophages that express increased PD-L1, and activated T cells not recruited to the tumor site.

Percutaneous Needle Biopsies of the Breast in Women Younger than 35 Years: Minimally or Excessively Invasive?

Percutaneous needle biopsy (PNB) of the breast is commonly used for diagnosis of breast pathology, but has been less studied in young women. We sought to determine the effectiveness and necessity of PNB in patients younger than 35 years of age. The charts of sequential patients <35 years who underwent PNB between February 2013 and May 2016 were reviewed; 181 PNB were performed in 127 patients. Median age was 30 years (13–34). Indications for PNB were Breast Imaging Reporting and Data System (BIRADS) ≥4 in 137 (75.7%) cases, with mass on imaging in 139 (76.8%). Carcinoma was diagnosed in 12 (6.6%), PNB in eight unique patients (6.3%). Other PNB pathology included atypia in four (2.2%) patients; papillary lesion, five (2.8%); benign lymph node, 10 (5.5%); fibroepithelial lesion, 15 (8.3%); benign breast tissue, 63 (34.8%); and fibroadenoma, 72 (39.8%). Women with atypia or malignancy were older than those with benign findings (30.9 vs 28.0 years, P = 0.002). No other patient or imaging factors were significantly associated with pathologic diagnosis on PNB. Routine PNB for all BIRADS 4 findings may be over-used in young women as most results are benign and subsequent surgical findings are concordant. Improved diagnostic accuracy of breast imaging is warranted to reduce unnecessary procedures.

Normative data for flow cytometry immunophenotyping of benign lymph nodes sampled by surgical biopsy

AimsTo create clinically relevant normative flow cytometry data for understudied benign lymph nodes and characterise outliers.MethodsClinical, histological and flow cytometry data were collected and distributions summarised for 380 benign lymph node excisional biopsies. Outliers for kappa:lambda light chain ratio, CD10:CD19 coexpression, CD5:CD19 coexpression, CD4:CD8 ratios and CD7 loss were summarised for histological pattern, concomitant diseases and follow-up course.ResultsWe generated the largest data set of benign lymph node immunophenotypes by an order of magnitude. B and T cell antigen outliers often had background immunosuppression or inflammatory disease but did not subsequently develop lymphoma.ConclusionsDiagnostic immunophenotyping data from benign lymph nodes provide normative ranges for clinical use. Outliers raising suspicion for B or T cell lymphoma are not infrequent (26% of benign lymph nodes). Caution is indicated when interpreting outliers in the absence of excisional biopsy or clinical history, particularly in patients with concomitant immunosuppression or inflammatory disease.