Axillary Lymphadenopathy After a COVID-19 Vaccine Booster Dose: Time to Resolution on Ultrasound Follow-Up and Associated Factors.

BACKGROUND. Because administration of booster doses of COVID-19 vaccines is ongoing, radiologists are continuing to encounter COVID-19 vaccine-related axillary lymphadenopathy on imaging. OBJECTIVE. The purposes of this study were to assess time to resolution of COVID-19 vaccine-related axillary lymphadenopathy identified on breast ultrasound after administration of a booster dose and to assess factors potentially associated with time to resolution. METHODS. This retrospective single-institution study included 54 patients (mean age, 57 years) with unilateral axillary lymphadenopathy ipsilateral to the site of injection of a booster dose of messenger RNA COVID-19 vaccine visualized on ultrasound (whether an initial breast imaging examination or follow-up to prior screening or diagnostic breast imaging) performed between September 1, 2021, and December 31, 2022, and who underwent follow-up ultrasound examinations until resolution of lymphadenopathy. Patient information was extracted from the EMR. Univariable and multivariable linear regression analyses were used to identify predictors of time to resolution. Time to resolution was compared with that in a previously described sample of 64 patients from the study institution that was used to evaluate time to resolution of axillary lymphadenopathy after the initial vaccination series. RESULTS. Six of the 54 patients had a history of breast cancer, and two had symptoms related to axillary lymphadenopathy (axillary pain in both patients). Among the 54 initial ultrasound examinations showing lymphadenopathy, 33 were screening examinations and 21 were diagnostic examinations. Lymphadenopathy had resolved a mean of 102 ± 56 (SD) days after administration of the booster dose and 84 ± 49 days after the initial ultrasound showing lymphadenopathy. Age, vaccine booster type (Moderna vs Pfizer-BioNTech), and history of breast cancer were not significantly associated with time to resolution in univariable or multivariable analyses (all p > .05). Time to resolution after administration of a booster dose was significantly shorter than time to resolution after administration of the first dose in the initial series (mean, 129 ± 37 days) (p = .01). CONCLUSION. Axillary lymphadenopathy after administration of a COVID-19 vaccine booster dose has a mean time to resolution of 102 days, shorter than the time to resolution after the initial vaccination series. CLINICAL IMPACT. The time to resolution after administration of a booster dose supports the current recommendation for a follow-up interval of at least 12 weeks when vaccine-related lymphadenopathy is suspected.

Major hemorrhage and mortality in COVID-19 patients on therapeutic anticoagulation for venous thromboembolism.

We observed multiple fatal intracranial hemorrhages shortly after initiating therapeutic anticoagulation for treatment of venous thromboembolism (VTE) in COVID-19 patients suggesting increased anticoagulation risk associated with COVID-19. The objective of this study is to quantify risk of major hemorrhage in hospitalized COVID-19 patients on therapeutic anticoagulation for deep venous thrombosis (DVT) or pulmonary embolism (PE). Hospitalized patients with COVID-19 receiving therapeutic anticoagulation for DVT, PE or both at four New York City hospitals were evaluated for hemorrhagic complications. These were categorized as major (including fatal) or clinically relevant non-major according to the criteria of the International Society of Thrombosis and Haemostasis. Hemorrhagic complications were correlated with clinical and laboratory data, ICD-10 code diagnoses and type of anticoagulation treatment. Minor hemorrhages were excluded. Major/clinically relevant hemorrhages occurred in 36 of 170 (21%) hospitalized COVID-19 patients being treated with therapeutic anticoagulation for VTE including 4 (2.4%) fatal hemorrhages. Hemorrhage was 3.4 times more likely with unfractionated heparin 27/76 (36%) compared to 8/81 (10%) with low molecular weight heparin (p = 0.002). Multivariate analysis showed that major hemorrhage was associated with intubation (p = 0.04) and elevated serum LDH (p < 0.001) and low fibrinogen (p = 0.05). Increased risk of hemorrhagic complications in treating VTE in hospitalized COVID-19 patients should be considered especially when using unfractionated heparin, in intubated patients, with low fibrinogen and/or elevated LDH. Checking serum fibrinogen and LDH before initiating therapeutic anticoagulation and monitoring coagulation parameters frequently may reduce bleeding complications.

Time for Resolution of COVID-19 Vaccine-Related Axillary Lymphadenopathy and Associated Factors.

BACKGROUND. The variable clinical course of subclinical lymphadenopathy detected on breast imaging after COVID-19 vaccination creates management challenges and has led to evolving practice recommendations. OBJECTIVE. The purpose of this study was to assess the duration of axillary lymphadenopathy ipsilateral to COVID-19 vaccination detected by breast imaging and to assess factors associated with the time until resolution. METHODS. This retrospective single-center study included 111 patients (mean age, 52 ± 12 years) with unilateral axillary lymphadenopathy ipsilateral to mRNA COVID-19 vaccine administration performed within the prior 8 weeks that was detected on breast ultrasound performed between January 1, 2021, and October 1, 2021, and who underwent follow-up ultrasound examinations at 4- to 12-week intervals until resolution of the lymphadenopathy. Patient information was extracted from medical records. Cortical thickness of the largest axillary lymph node on ultrasound was retrospectively measured and was considered enlarged when greater than 3 mm. Multivariable linear regression analysis was used to identify independent predictors of time until resolution. RESULTS. The mean cortical thickness at the initial ultrasound examination was 4.7 ± 1.2 mm. The lymphadenopathy resolved a mean of 97 ± 44 days after the initial ultrasound examination, 127 ± 43 days after the first vaccine dose, and 2.4 ± 0.6 follow-up ultrasound examinations. A significant independent predictor of shorter time to resolution was Pfizer-BioNTech (rather than Moderna) vaccination (ß = -18.0 [95% CI, -34.3 to -1.7]; p = .03]. Significant independent predictors of longer time to resolution were receipt of the second dose after the initial ultrasound examination (ß = 19.2 [95% CI, 3.1-35.2]; p = .02) and greater cortical thickness at the initial ultrasound examination (ß = 8.0 [95% CI, 1.5-14.5]; p = .02). Patient age, history of breast cancer, and axillary symptoms were not significantly associated with time to resolution (all p > .05). CONCLUSION. Axillary lymphadenopathy detected with breast ultrasound after COVID-19 mRNA vaccination lasts longer than reported in initial vaccine clinical trials. CLINICAL IMPACT. The prolonged time to resolution supports not delaying screening mammography because of recent COVID-19 vaccination. It also supports the professional society recommendation of a follow-up interval of at least 12 weeks when vaccine-related lymphadenopathy is suspected.

Predictors of acute deep venous thrombosis in patients hospitalized for COVID-19.

ABSTRACT: Deep venous thrombosis (DVT) is associated with high mortality in coronavirus disease 2019 (COVID-19) but there remains uncertainty about the benefit of anti-coagulation prophylaxis and how to decide when ultrasound screening is indicated. We aimed to determine parameters predicting which COVID-19 patients are at risk of DVT and to assess the benefit of prophylactic anti-coagulation.Adult hospitalized patients with positive severe acute respiratory syndrome coronavirus-2 reverse transcription-polymerase chain reaction (RT-PCR) undergoing venous duplex ultrasound for DVT assessment (n = 451) were retrospectively reviewed. Clinical and laboratory data within 72 hours of ultrasound were collected. Using split sampling and a 10-fold cross-validation, a random forest model was developed to find the most important variables for predicting DVT. Different d-dimer cutoffs were examined for classification of DVT. We also compared the rate of DVT between the patients going and not going under thromboprophylaxis.DVT was found in 65 (14%) of 451 reverse transcription-polymerase chain reaction positive patients. The random forest model, trained and cross-validated on 2/3 of the original sample (n = 301), had area under the receiver operating characteristic curve = 0.91 (95% confidence interval [CI]: 0.85-0.97) for prediction of DVT in the test set (n = 150), with sensitivity = 93% (95%CI: 68%-99%) and specificity = 82% (95%CI: 75%-88%). The following variables had the highest importance: d-dimer, thromboprophylaxis, systolic blood pressure, admission to ultrasound interval, and platelets. Thromboprophylaxis reduced DVT risk 4-fold from 26% to 6% (P < .001), while anti-coagulation therapy led to hemorrhagic complications in 14 (22%) of 65 patients with DVT including 2 fatal intra-cranial hemorrhages. D-dimer was the most important predictor with area under curve = 0.79 (95%CI: 0.73-0.86) by itself, and a 5000 ng/mL threshold at 7 days postCOVID-19 symptom onset had 75% (95%CI: 53%-90%) sensitivity and 81% (95%CI: 72%-88%) specificity. In comparison with d-dimer alone, the random forest model showed 68% versus 32% specificity at 95% sensitivity, and 44% versus 23% sensitivity at 95% specificity.D-dimer >5000 ng/mL predicts DVT with high accuracy suggesting regular monitoring with d-dimer in the early stages of COVID-19 may be useful. A random forest model improved the prediction of DVT. Thromboprophylaxis reduced DVT in COVID-19 patients and should be considered in all patients. Full anti-coagulation therapy has a risk of life-threatening hemorrhage.

Ink on the move: tattoo pigment resembling axillary lymph node calcifications.

High-density foci within axillary lymph nodes are associated with a number of potential diagnoses. In this case series, we present four tattooed patients who had mammographic findings that demonstrated high-density material in axillary lymph nodes, indicative of tattoo pigment migration. The aim of presenting these cases is to highlight the importance of recognizing such pigment migration in order to help breast radiologists form an appropriate differential diagnosis that might include this entity.