Reactive lymphadenopathy due to Pfizer-BioNTech COVID-19 vaccine: a case report / Linfadenopatía reactiva por vacuna Pfizer-BioNTech para COVID-19: reporte de un caso

Uno de los efectos secundarios encontrados en pacientes con antecedente de vacunación por COVID-19, especialmente con la vacuna Pfizer-BioNTech, es la aparición de múltiples adenopatías hiperplásicas, principalmente en los ganglios linfáticos axilares, supraclaviculares e infraclaviculares ipsilaterales al sitio de vacunación. Presentamos el caso de una paciente femenina de 33 años, con aparición de masa dolorosa supraclavicular izquierda, quien una semana antes había sido vacunada con la primera dosis de la vacuna Pfizer-BioNTech en región deltoidea izquierda. Los hallazgos citológicos fueron sugestivos de una enfermedad linfoproliferativa, y el estudio histopatológico reveló linfadenopatía reactiva con proliferación de inmunoblastos B activados, secundaria a la vacunación contra COVID-19. Aportamos a la literatura con la caracterización de los hallazgos histopatológicos de la linfadenopatía posvacunación contra COVID-19. Es importante que los médicos tratantes y radiólogos estén familiarizados con este diagnóstico diferencial, para brindar recomendaciones adecuadas basadas en un seguimiento a corto plazo, en lugar de realizar biopsias, intervenciones y conductas inmediatas innecesarias en el manejo de los pacientes

One of the side effects found in patients with a history of vaccination for COVID-19, especially with the Pfizer-BioNTech vaccine, is the appearance of multiple hyperplastic adenopathies, mainly axillary, supraclavicular and infraclavicular lymph nodes ipsilateral to the vaccination site. We present the case of a 33-year-old female patient, with the appearance of a painful left supraclavicular mass, who was vaccinated a week earlier with the first dose of the Pfizer-BioNTech vaccine in the left deltoid region. The cytological findings were suggestive of a lymphoproliferative disease, and the histopathological study revealed reactive lymphadenopathy with proliferation of activated B immunoblasts, secondary to vaccination against COVID-19. We contribute to the literature with the characterization of the histopathological findings of COVID-19 post-vaccination lymphadenopathy. It is important for treating physicians and radiologists to be familiar with this differential diagnosis, in order to provide appropriate recommendations based on short-term follow-up, instead of performing unnecessary immediate biopsies or interventions in patient management.

Fine needle aspiration in COVID-19 vaccine-associated lymphadenopathy.

AIMS: With ongoing intensive vaccination programme against COVID-19, numerous cases of adverse reactions occur, some of which represent rare events. Enlargement of the injection site’s draining lymph nodes is increasingly reported, but is not yet widely recognised as being possibly associated with recent vaccination. As patients at risk of a severe course of COVID-19, indicated by their medical history such as a previous diagnosis of malignancy, receive priority vaccination, newly palpable lymph nodes raise concerns of disease progression. In this case series, we report on five patients who presented with enlarged lymph nodes after COVID-19 vaccination. METHODS: Sonography guided fine needle aspiration (FNA) was performed in five patients presenting with PET-positive and/or enlarged lymph nodes after COVID-19 vaccination with either the Pfizer-BioNTech or Moderna vaccine. RESULTS: COVID-19 vaccination had been carried out in all cases, with an interval of between 3 and 33 days prior to FNA. Three of five patients had a history of neoplasms. The vaccine was administered into the deltoid muscle, with subsequent enlargement of either the cervical, supra-, infra- or retroclavicular, or axillary lymph nodes, in four out of five cases ipsilaterally. In all cases, cytology and additional analyses showed a reactive lymphadenopathy without any sign of malignancy. CONCLUSIONS: Evidence of newly enlarged lymph nodes after recent COVID-19 vaccination should be considered reactive in the first instance, occurring owing to stimulation of the immune system. A clinical follow-up according to the patient’s risk profile without further diagnostic measures is justified. In the case of preexisting unilateral cancer, vaccination should be given contralaterally whenever possible. Persistently enlarged lymph nodes should be re-evaluated (2 to) 6 weeks after the second dose, with additional diagnostic tests tailored to the clinical context. Fine needle aspiration is a well established, safe, rapid and cost-effective method to investigate an underlying malignancy, especially metastasis. Recording vaccination history, including date of injection, site and vaccine type, as well as communicating this information to treating physicians of different specialties is paramount for properly handling COVID-19 vaccine-associated lymphadenopathy.

Prevalence of Adenopathy at Chest Computed Tomography After Vaccination for Severe Acute Respiratory Syndrome Coronavirus 2.

OBJECTIVE: This study aimed to determine the prevalence of axillary and subpectoral (SP) lymph nodes after ipsilateral COVID-19 vaccine administration on chest computed tomography (CT). METHODS: Subjects with chest CTs between 2 and 25 days after a first or second vaccine dose, December 15, 2020, to February 12, 2021, were included. Orthogonal measures of the largest axillary and SP nodes were recorded by 2 readers blinded to vaccine administration and clinical details. A mean nodal diameter discrepancy of ≥6 mm between contralateral stations was considered positive for asymmetry. Correlation with the side of vaccination, using a Spearman rank correlation, was performed on the full cohort and after excluding patients with diseases associated with adenopathy. RESULTS: Of the 138 subjects (81 women, 57 men; mean [SD] age, 74.4 ± 11.7 years), 48 (35%) had asymmetrically enlarged axillary and/or SP lymph nodes, 42 (30%) had ipsilateral, and 6 (4%) had contralateral to vaccination ( P = 0.003). Exclusion of 29 subjects with conditions associated with adenopathy showed almost identical correlation, with asymmetric nodes in 32 of 109 (29%) ipsilateral and in 5 of 109 (5%) contralateral to vaccination ( P = 0.002). CONCLUSIONS: Axillary and/or SP lymph nodes ipsilateral to vaccine administration represents a clinical conundrum. Asymmetric nodes were detected at CT in 30% of subjects overall and 29% of subjects without conditions associated with adenopathy, approximately double the prevalence rate reported to the Centers for Disease Control and Prevention by vaccine manufacturers. When interpreting examinations correlation with vaccine administration timing and site is important for pragmatic management.

Severe Pancytopenia After COVID-19 Revealing a Case of Primary Bone Marrow Diffuse Large B Cell Lymphoma.

BACKGROUND Diffuse large B cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL). While bone marrow (BM) involvement is common in lymphoma, primary bone marrow (PBM) DLBCL is extremely rare. We present a case of PBM DLBCL discovered in a patient with COVID-19. CASE REPORT An 80-year-old man presented with generalized abdominal pain, weight loss, fever, fatigue, anorexia, and watery diarrhea over a 3-month period. Physical examination was unremarkable. Laboratory workup revealed anemia, thrombocytopenia, and elevated inflammation markers. SARS-COV-2 PCR was positive, while blood cultures were negative. A rapid decline in the white blood cell count in the following days prompted a BM biopsy, confirming the diagnosis of PBM DLBCL. Computed tomography (CT) did not show thoracic or abdominal lymphadenopathy. The patient received packed red blood cell and platelet transfusions, granulocyte colony-stimulating factor (G-CSF) for pancytopenia, and empirical antibiotics for suspected infection. Due to active COVID-19 and advanced age, cytotoxic chemotherapy was delayed. Rituximab and prednisone were initiated on day 9, followed by an infusion reaction, which led to treatment discontinuation. He died 2 days later. CONCLUSIONS Diagnosing PBM malignancy is challenging, especially with coexisting infection. It is essential to suspect underlying BM malignancy in patients with clinical deterioration and worsening pancytopenia despite adequate treatment. The diagnosis of PBM DLBCL requires the absence of lymphadenopathy, and the presence of histologically confirmed DLBCL. Prompt management with combination chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) with/without hematopoietic stem cell transplant can improve the prognosis.

COVID-19 Vaccine-Associated Lymphadenopathy Mimicking Regrowth of Axillary Lymph Node Metastasis of Lung Adenocarcinoma.

We encountered a woman with re-enlarged axillary lymph nodes during a computed tomography (CT) scan for surveillance of lung adenocarcinoma with axillary lymph node metastasis at the initial diagnosis that had shrunk with standard chemotherapy. We first suspected cancer recurrence and considered a change in the chemotherapeutic regimen. However, after careful history taking regarding the timing of her Coronavirus Disease 2019 (COVID-19) vaccination, and subsequent careful, close follow-up, radiological shrinkage suggested a strictly benign cause. Especially in lung cancer with a medical history of axillary lymph node involvement, cliniciansshould be aware that vaccine-associated lymphadenopathy can mimic cancer recurrence and sometimesprompt serious misjudgment regarding a current treatment course and strategy.

Axillary lymph node characteristics in breast cancer patients versus post-COVID-19 vaccination: Overview of current evidence per imaging modality.

BACKGROUND: Axillary lymph node characteristics on axillary ultrasound (US), breast MRI and 18F-FDG PET/CT are relevant at breast cancer diagnosis. Axillary lymphadenopathy after COVID-19 vaccination has been frequently reported. This may cause a diagnostic dilemma, particularly in the ipsilateral axilla in women who have a either a recent diagnosis of breast cancer or a history of breast cancer. This review provides an overview of the current evidence regarding axillary lymph node characteristics at breast cancer diagnosis versus "post-COVID-19 vaccination". METHODS: A non-systematic narrative review was performed. Studies describing axillary lymph node characteristics per imaging modality (axillary US, breast MRI and 18F-FDG PET/CT) in breast cancer patients versus post-COVID-19 vaccination were selected and used for the current study. RESULTS: The morphologic characteristics and distribution of abnormal nodes on US may differ from the appearance of metastatic adenopathy since diffuse cortical thickening of the lymph nodes is the most observed characteristic after vaccination, whereas metastases show as most suspicious characteristics focal cortical thickening and effacement of the fatty hilum. Current evidence on MRI and 18F-FDG on morphologic characteristics of axillary lymphadenopathy is missing, although it was suggested that vaccine related lymphadenopathy is more likely to be present in level 2 and 3 nodes than metastatic nodes. Reported frequencies of lymphadenopathy post-COVID-19 vaccination range from 49% to 85% (US), 29% (breast MRI) and 14.5% to 53.9% (18F-FDG PET/CT). Several factors may impact the presence or extent of lymphadenopathy post-COVID-19 vaccination: injection site, type of vaccine (i.e., mRNA versus vector), time interval (days) between vaccination and imaging, previous history of COVID-19 pneumonia, and first versus second vaccine dose. CONCLUSION: Although lymph node characteristics differ at breast cancer diagnosis versus post-COVID-19 vaccination, clinical information regarding injection site, vaccine type and vaccination date needs to be documented to improve the interpretation and guide treatment towards the next steps of action.

Axillary adenopathy detected on breast MRI following COVID-19 vaccination: outcomes and follow-up recommendations.

This retrospective study presents 110 patients with suspected COVID-19 vaccine-related axillary adenopathy on breast MRI. Our study aimed to assess the outcomes of axillary adenopathy detected on breast MRI performed within one year after COVID-19 vaccination. The median time between the COVID-19 vaccine and breast MRI was shorter in patients with detected adenopathy compared to patients without detected adenopathy (6 weeks [2-17] versus 15 [7-24] weeks, p < 0.001). Unilateral axillary adenopathy detected on breast MRI had a low malignancy rate (3.3%), and no cases of malignant axillary adenopathy were diagnosed without a known breast cancer in the ipsilateral breast. Our findings suggest that unilateral axillary adenopathy identified on breast MRI ipsilateral to a recent COVID-19 vaccination can be considered benign in the absence of a suspicious breast finding or known breast cancer. Regardless of vaccine status and timing, unilateral axillary adenopathy detected on MRI evaluation with a known malignancy or suspicious breast finding should be considered suspicious. This will avoid unnecessary scheduling constraints, patient anxiety, and cost, without delaying diagnosis of metastatic breast cancer.

FDG PET/CT radiomics as a tool to differentiate between reactive axillary lymphadenopathy following COVID-19 vaccination and metastatic breast cancer axillary lymphadenopathy: a pilot study.

OBJECTIVES: To evaluate if radiomics with machine learning can differentiate between F-18-fluorodeoxyglucose (FDG)-avid breast cancer metastatic lymphadenopathy and FDG-avid COVID-19 mRNA vaccine-related axillary lymphadenopathy. MATERIALS AND METHODS: We retrospectively analyzed FDG-positive, pathology-proven, metastatic axillary lymph nodes in 53 breast cancer patients who had PET/CT for follow-up or staging, and FDG-positive axillary lymph nodes in 46 patients who were vaccinated with the COVID-19 mRNA vaccine. Radiomics features (110 features classified into 7 groups) were extracted from all segmented lymph nodes. Analysis was performed on PET, CT, and combined PET/CT inputs. Lymph nodes were randomly assigned to a training (n = 132) and validation cohort (n = 33) by 5-fold cross-validation. K-nearest neighbors (KNN) and random forest (RF) machine learning models were used. Performance was evaluated using an area under the receiver-operator characteristic curve (AUC-ROC) score. RESULTS: Axillary lymph nodes from breast cancer patients (n = 85) and COVID-19-vaccinated individuals (n = 80) were analyzed. Analysis of first-order features showed statistically significant differences (p < 0.05) in all combined PET/CT features, most PET features, and half of the CT features. The KNN model showed the best performance score for combined PET/CT and PET input with 0.98 (± 0.03) and 0.88 (± 0.07) validation AUC, and 96% (± 4%) and 85% (± 9%) validation accuracy, respectively. The RF model showed the best result for CT input with 0.96 (± 0.04) validation AUC and 90% (± 6%) validation accuracy. CONCLUSION: Radiomics features can differentiate between FDG-avid breast cancer metastatic and FDG-avid COVID-19 vaccine-related axillary lymphadenopathy. Such a model may have a role in differentiating benign nodes from malignant ones. KEY POINTS: • Patients who were vaccinated with the COVID-19 mRNA vaccine have shown FDG-avid reactive axillary lymph nodes in PET-CT scans. • We evaluated if radiomics and machine learning can distinguish between FDG-avid metastatic axillary lymphadenopathy in breast cancer patients and FDG-avid reactive axillary lymph nodes. • Combined PET and CT radiomics data showed good test AUC (0.98) for distinguishing between metastatic axillary lymphadenopathy and post-COVID-19 vaccine-associated axillary lymphadenopathy. Therefore, the use of radiomics may have a role in differentiating between benign from malignant FDG-avid nodes.

Impact of Mediastinal Lymphadenopathy on the Severity of COVID-19 Pneumonia: A Nationwide Multicenter Cohort Study.

BACKGROUND: We analyzed the differences between clinical characteristics and computed tomography (CT) findings in patients with coronavirus disease 2019 (COVID-19) to establish potential relationships with mediastinal lymphadenopathy and clinical outcomes. METHODS: We compared the clinical characteristics and CT findings of COVID-19 patients from a nationwide multicenter cohort who were grouped based on the presence or absence of mediastinal lymphadenopathy. Differences between clinical characteristics and CT findings in these groups were analyzed. Univariate and multivariate analyses were performed to determine the impact of mediastinal lymphadenopathy on clinical outcomes. RESULTS: Of the 344 patients included in this study, 53 (15.4%) presented with mediastinal lymphadenopathy. The rate of diffuse alveolar damage pattern pneumonia and the visual CT scores were significantly higher in patients with mediastinal lymphadenopathy than in those without (P < 0.05). A positive correlation between the number of enlarged mediastinal lymph nodes and visual CT scores was noted in patients with mediastinal lymphadenopathy (Spearman's ρ = 0.334, P < 0.001). Multivariate analysis showed that mediastinal lymphadenopathy was independently associated with a higher risk of intensive care unit (ICU) admission (odds ratio, 95% confidence interval; 3.25, 1.06-9.95) but was not significantly associated with an increased risk of in-hospital death in patients with COVID-19. CONCLUSION: COVID-19 patients with mediastinal lymphadenopathy had a larger extent of pneumonia than those without. Multivariate analysis adjusted for clinical characteristics and CT findings revealed that the presence of mediastinal lymphadenopathy was significantly associated with ICU admission.

COVID-19 vaccine associated axillary lymphadenopathy - A systematic review.

INTRODUCTION: ; COVID-19 vaccines are commonly administered intramuscularly to the arm. Axillary lymphadenopathy has been reported as an adverse event after COVID-19 vaccination. In patients with breast cancers who received COVID-19 vaccination, presence of ipsilateral (or contralateral) lymphadenopathy poses diagnostic dilemma. This systematic review aims to evaluate the incidence and clinical characteristics of vaccine associated axillary lymphadenopathy. METHODS: ; The systematic review was conducted with accordance to the PRISMA statement. The search terms used were "Vaccine" OR "Vaccination" AND "Lymphadenopathy" OR "Lymph node" AND "Covid-19″. RESULTS: ; 31 studies or reports were identified using the predefined keywords from the systematic review protocol. After excluding irrelevant papers (such as guidelines, reviews, opinions and commentaries), 10 studies or reports were included in the review.Pooled incidence of clinically detectable lymphadenopathy after COVID-19 vaccination was 91/22,532 (0.4%). Mean size of the vaccine associated axillary lymphadenopathy was 18.2 mm (Range 16 - 21 mm). Mean duration from vaccination to occurrence of axillary lymphadenopathy was 6.9 days (Range 2 - 18 days). In a study on 119 patients, enlarged axillary lymphadenopathy resolves in 4 to 5 weeks. CONCLUSION: ; Vaccine associated axillary lymphadenopathy is not uncommon. Management of it is based on multidisciplinary decision with patient demographics, vaccination history and radiological finding being taken into account. Additional imaging and biopsy may lead to unnecessary healthcare burden. Proper arrangement of vaccination and imaging regarding timing and laterality should be advocated to avoid confusion and patient anxiety.

COVID-19 vaccine-related axillary lymphadenopathy in breast cancer patients: Case series with a review of literature.

PURPOSE: Lymphadenopathy (LAP) after COVID-19 vaccination in patients with a diagnosis of cancer has been challenging. We analyzed imaging and clinical features from early cases of axillary LAP in six COVID-19 vaccine recipients with a history of breast cancer. METHOD: Among the patients with a history of breast cancer and recent COVID-19 vaccine administration, six patients who showed isolated axillary LAP were gathered. Radiologic features were reviewed from breast ultrasound, chest computed tomography, and breast magnetic resonance imaging. Clinical and pathological information were obtained for analysis. RESULTS: The interval between ultrasound detection of LAP and last COVID-19 vaccine administration ranged from 14 to 28 days (mean 21.67 days). Round shape of the lymph node and irregular cortex were noted in 2 and 0 cases, respectively. Mean maximum cortical thickness, length to width ratio and interval aggravation in maximum cortical thickening were 4.2 mm, 1.34, and 2.81-fold with cut-off value of 3 mm, 1.5, 2.0-fold, respectively. CONCLUSION: We observed axillary LAP ipsilateral to a recent vaccine administration persisting longer than what the Centers for Disease Control and Prevention announced. In our patients, COVID-19 vaccine-related LAP tended to show increased cortical thickness without cortical irregularity. Oncologist as well as radiologist should be familiar with the fact that COVID-19 vaccines, regardless of vaccine type or dosage, can frequently cause ipsilateral axillary LAP, showing some suspicious features more often than others, and can persist longer than anticipated so that both over- and underdiagnosis can be avoided. We report our observations in six patients and provide an exhaustive review of the published literature.

COVID-19 post-vaccination lymphadenopathy: Report of cytological findings from fine needle aspiration biopsy.

The coronavirus COVID-19 pandemic has spurred the rapid development of vaccines, with vaccination programmes already underway in many countries. Regional lymphadenopathy is one of the documented side effects of vaccination. We document the fine needle aspiration cytological findings of an enlarged supraclavicular lymph node in a 34-year-old Asian female following the first dose of the Pfizer-BioNTech COVID-19 mRNA vaccine, which appears to be the first such report in a premorbidly well patient with no known history of malignancy. The cytological findings featured a reactive pattern in keeping with follicular hyperplasia, with prominent germinal centre elements including lymphohistiocytic aggregates and tingible-body macrophages. Despite an increased proportion of larger lymphocytes, the overall pattern was in keeping with a reactive pattern, bearing in mind the temporal and geographic relation to the vaccination injection. In instances of localised lymphadenopathy, particularly in supraclavicular or axillary locations, pathologists should be cognizant of the possibility of post-vaccination reactive lymphadenopathy, and seek clinical and radiological hints favouring a benign process, whilst recognising potential morphological overlaps with lymphoproliferative disorders. Awareness of this diagnostic pitfall is especially important as COVID-19 vaccination coverage is ramped up worldwide, leading to an expected increase in incidence of post-vaccination reactive lymphadenopathy.

COVIDiag: a clinical CAD system to diagnose COVID-19 pneumonia based on CT findings.

OBJECTIVES: CT findings of COVID-19 look similar to other atypical and viral (non-COVID-19) pneumonia diseases. This study proposes a clinical computer-aided diagnosis (CAD) system using CT features to automatically discriminate COVID-19 from non-COVID-19 pneumonia patients. METHODS: Overall, 612 patients (306 COVID-19 and 306 non-COVID-19 pneumonia) were recruited. Twenty radiological features were extracted from CT images to evaluate the pattern, location, and distribution of lesions of patients in both groups. All significant CT features were fed in five classifiers namely decision tree, K-nearest neighbor, naïve Bayes, support vector machine, and ensemble to evaluate the best performing CAD system in classifying COVID-19 and non-COVID-19 cases. RESULTS: Location and distribution pattern of involvement, number of the lesion, ground-glass opacity (GGO) and crazy-paving, consolidation, reticular, bronchial wall thickening, nodule, air bronchogram, cavity, pleural effusion, pleural thickening, and lymphadenopathy are the significant features to classify COVID-19 from non-COVID-19 groups. Our proposed CAD system obtained the sensitivity, specificity, and accuracy of 0.965, 93.54%, 90.32%, and 91.94%, respectively, using ensemble (COVIDiag) classifier. CONCLUSIONS: This study proposed a COVIDiag model obtained promising results using CT radiological routine features. It can be considered an adjunct tool by the radiologists during the current COVID-19 pandemic to make an accurate diagnosis. KEY POINTS: • Location and distribution of involvement, number of lesions, GGO and crazy-paving, consolidation, reticular, bronchial wall thickening, nodule, air bronchogram, cavity, pleural effusion, pleural thickening, and lymphadenopathy are the significant features between COVID-19 from non-COVID-19 groups. • The proposed CAD system, COVIDiag, could diagnose COVID-19 pneumonia cases with an AUC of 0.965 (sensitivity = 93.54%; specificity = 90.32%; and accuracy = 91.94%). • The AUC, sensitivity, specificity, and accuracy obtained by radiologist diagnosis are 0.879, 87.10%, 88.71%, and 87.90%, respectively.

Coronavirus Disease 2019 Suspicion: A Case Report Regarding a Male Emergency Medical Service Pilot With Newly Diagnosed Sarcoidosis.

A 38-year-old emergency medical service Bell 214 male pilot with a dry cough, fever, anorexia, fatigue, and sweating for the past 3 days; an oral temperature of 38°C; blood pressure of 105/65 mm Hg; heart rate of 94 beats/min; respiratory rate of 21 breaths/min; and pulse oximetry of 93% on room air was suspicious for coronavirus disease 2019. Surprisingly, reverse transcription polymerase chain reaction was negative, but bilateral hilar adenopathy was reported in his chest radiography as a new challenge. The pathologic report of the adenopathy biopsy was noncaseating sarcoid-type granulomas. Serologic tests showed a serum angiotensin-converting enzyme level of 58 nmol/mL/min. The bronchoalveolar lavage fluid CD4/CD8 ratio was 3.68. The bronchoalveolar lavage findings provided an accurate sarcoidosis diagnosis, and a high-resolution computed tomographic scan revealed stage 1 pulmonary involvement. Because of the pulmonary involvement, clinical manifestations, use of inhaled fluticasone, and need for longer and accurate follow-up and to protect against coronavirus disease 2019, he has been temporarily suspended until the final assignment.

CT imaging features of COVID-19 pneumonia: initial experience from Turkey.

PURPOSE: We aimed to demonstrate the computed tomography (CT) findings observed at the initial presentation of coronavirus disease 2019 (COVID-19) pneumonia and reveal the most frequent infiltration and distribution patterns of the disease. METHODS: One hundred and eighty-five patients (87 men, 98 women; mean age, 48.7 years), who underwent RT-PCR sampling and high-resolution CT examination in our hospital between March 15, 2020, and April 15, 2020, and got a definitive diagnosis of COVID-19 disease via initial or follow-up RT-PCR test, were included in the study. We comprehensively analyzed the most common and relatively rare CT imaging features (e.g., distribution pattern, density of the lesions, additional CT signs) in patients diagnosed with COVID-19 pneumonia. RESULTS: Thirty-eight patients (20.6%) had no evidence of pneumonia on their initial high-resolution CT images. Among 147 patients (79.4%) who had parenchymal infiltration consistent with pneumonia, 10 (6.8%) had a negative baseline RT-PCR test, and positivity was detected as a result of repeated tests. Most of the patients had multifocal (89.1%) and bilateral (86.4%) lesions. The most common location, right lower lobe, was affected in 87.8% of the patients. Lesions were distributed predominantly at peripheral (87.1%) and posterior (46.3%) areas of lung parenchyma. Most of the patients had pure ground glass opacity (GGO) (82.3%) followed by GGO with consolidation (32.7%) and crazy paving pattern (21.8%). Pure consolidation, solid nodules, halo sign, reverse halo sign, vascular enlargement, subpleural line, air-bronchogram, and bronchiectasis were the other findings observed in at least 15% of the cases. Halo sign, acinar nodules, air-bubble sign, pleural thickening and effusion, mediastinal and/or hilar lymphadenopathy were seen rarely (2%-12.9%). Pericardial effusion, pneumothorax, cavitation, and tree-in-bud pattern were not detected in our study group. CONCLUSION: Multifocal and bilateral GGO infiltration predominantly distributed in peripheral, posterior, and lower lung areas was the most common infiltration pattern.

The characteristics and clinical value of chest CT images of novel coronavirus pneumonia.

AIM: To investigate the characteristics and clinical value of chest computed tomography (CT) images of novel coronavirus pneumonia (NCP). MATERIALS AND METHODS: Clinical data and CT images of 80 cases of NCP were collected. The clinical manifestations and laboratory test results of the patients were analysed. The lesions in each lung segment of the patient's chest CT images were characterised. Lesions were scored according to length and diffusivity. RESULTS: The main clinical manifestations were fever, dry cough, fatigue, a little white sputum, or diarrhoea. A total of 1,702 scored lesions were found in the first chest CT images of 80 patients. The lesions were located mainly in the subpleural area of the lungs (92.4%). Most of the lesions were ground-glass opacity, and subsequent fusions could increase in range and spread mainly in the subpleural area. Pulmonary consolidation accounted for 44.1% of all of the lesions. Of the 80 cases, 76 patients (95%) had bilateral lung disease, four (5%) patients had unilateral lung disease, and eight (10%) patients had cord shadow. CONCLUSION: The chest CT of NCP patients is characterised by the onset of bilateral ground-glass lesions located in the subpleural area of the lung, and progressive lesions that result in consolidation with no migratory lesions. Pleural effusions and mediastinal lymphadenopathy are rare. As patients can have inflammatory changes in the lungs alongside a negative early nucleic acid test, chest CT, in combination with epidemiological and laboratory tests, is a useful examination to evaluate the disease and curative effect.