key: cord-0905166-8qtdrs1u
authors: BENSLIMA, N.; KASSIMI, M.; BERRADA, S.; JAOUAD, M.R CHERKAOUI; Hajjij, A; DINI, N.; MAHI, M.
title: Acute pulmonary embolism mimicking COVID-19 pneumonia
date: 2021-05-09
journal: Radiol Case Rep
DOI: 10.1016/j.radcr.2021.04.078
sha: e2d4efb86811b582748c40e1d82afb441dbdd1cd
doc_id: 905166
cord_uid: 8qtdrs1u

The case of 21-year-old man with an asthma history from childhood presenting severe respiratory distress associated with a right lower thoracic pain has been studied. The non-contrast Computed Tomography (CT)-chest scan showed a basal ground-glass opacity (GGO) of the right lung leading to suspicion of COVID-19’s pneumonia. However, the molecular RT-PCR test and blood serology were negative while laboratory analyses revealed high levels of D-dimers (D-D). In addition, two repeated COVID-19 tests were negative. A thoracic CT angiography was disclosed due to the persistence of pain at the lower right thoracic side and hemoptysis that shows a bilateral distal pulmonary embolism with a right-sided basal subsegmental ischemia. We discuss a fortuitous discovery of pulmonary embolism associated with peripheral basal ground-glass opacities similar to radiological manifestations of SARS-CoV-2 pneumonia. artery embolism; CT chest angiography; Covid-19; ground-glass opacity; pneumonia; chest pain

Acute pulmonary embolism (APE) is the most serious clinical presentation of venous thrombo-embolism (VTE) with fatal pulmonary embolism (PE) being a common cause of sudden death. PE is the third most frequent cardiovascular disease after acute myocardial infarction (AMI) and stroke, with an annual incidence of 1-2 per 1,000 people (100-200 per 100,000 inhabitants) (1). APE is characterized by numerous clinical manifestations which are the result of a complex interplay between different organs. The symptoms are therefore various and part of a complex clinical picture (1). For these reasons, despite being common, APE often remains elusive as a diagnosis and practitioners should maintain a high level of suspicion for this disease in high-risk patients (2). Pulmonary Computed Tomography angiography (CTA) is the imaging modality of choice in suspected APE due to the technical advancements along with the immediate and widespread availability of this test. The CTA is well established as a fast and reliable method to exclude or diagnose PE (3).

It has been shown that there is a causal link between APE and the occurrence of ground glass opacity (GGO) defined as hazy increased opacity of the lung, with preservation of bronchial and vascular margins (4). This radiological finding is also common in SARS-CoV-2 pneumonia' (5) which may be confusing during this pandemic period. The scope of this report is to investigate if the presence of ground-glass opacities in COVID-19 pnemomia doesn't omit other causes of ground-glass opacities.

The case of a 21-year-old man with asthma and allergies history since childhood. This case showed no indication of drug intoxication and was admitted to our institution for brutal dyspnea with lower pain in the right side associated with hemoptysis of mild abundance and fever. We suspected a SARS-CoV-2 pulmonary infection considering the clinical presentation and the actual pandemic. Thereafter, he was admitted to an isolation ward while laboratory and radiological investigations were performed. During the few months before and after hospitalization, the patient had no manifestations of COVID-19 pneumonia.

A laboratory report showed a high level of leukocytosis at 14000/mm3 [4000-11000/ mm3]* 23% of which were eosinophils [0.02-0.63/ mm3]*, a high level of D-Dimers (5000 u/ml) [<500 u/ml]*, thrombocytopenia (124000/mm) [150000-400000/ mm3]*, a high level of blood ferritinemia (702 ng/ml) [30-300 ng/ml]*, and C-reactive-protein (90mg/l) [<8 u/ml]*.

The molecular RT-PCR test for COVID-19, as well as serology, were negative. A CT-chest scan without contrast was performed at the admission. Yet, lower thoracic chest pain, cough, and hemoptysis were persistent, therefore a CT chest angiography was realized after 24 hours. A Doppler Ultrasound of the lower limbs and echocardiography were realized during the patient's hospitalization. A non-enhanced chest CT scan has shown a peripheral subpleural ground-glass opacity in the right lower segment (fig1). No other anomalies were found. Accordingly, the initial diagnosis of COVID-19 pneumonia was held.

With the progressive intensive pain of the right lung and hemoptysis and the fact that the molecular RT-PCR test and serology for COVID-19 were negative, CT chest angiography showed total occlusion of the posterior branch of the right inferior pulmonary artery and partial occlusion of the inferior branch of the left pulmonary artery (fig 2) . We also noticed a condensation and extension of the pre-existing ground-glass opacity associated with low pleural effusion (fig3). The diagnosis of bilateral peripheral pulmonary embolism causing a right posterobasal pulmonary infarction was retained. A curative dose of anticoagulants and corticosteroids was introduced. The patient did not show manifestations of COVID-19 infection during the hospitalization and a one mounth follow-up. Two Repeated COVID-19 tests were negative. The thoracic CT angiography after one month showed recanalization of the pulmonary artery that was initially occluded and a decrease of right basal condensation (fig 4) .

The criteria for suspicion of a viral acute respiratory syndrome due to COVID-19 was established by the World Health Organization (WHO). The suspicion is based on anamnestic, epidemiologic, biological, and radiological data (6). This was initially about the virus invasion at the alveolus level which spreads to the interstitium causing more dense condensation (7).

During the pandemic, the no-contrast chest CT scan was used for the diagnosis and mass screening especially for patients who initially had a negative RT-PCR test. Also, it was the first assessment in emergency structures where the results of RT-PCR and serology are late.

Indeed, the RT-PCR detection of viral nucleic acid in the airways, presents 94% sensitivity and 37% specificity (8) , while the CT chest scanner presents 91% specificity and a 90% sensitivity (9) .

Ground-glass types of alveolar consolidation are no specific and could lead to many etiologies, oedema (of the cardiogenic origin or acute respiratory distress syndrome (ARDS)), hemorrhage (pulmonary trauma, arterial rupture, embolic infarction), inflammation (fibrosis, hypersensitivity, acute or chronic eosinophilia), an attack by toxic inhalation with ":paraquat" or an invasion by tumor cells (broncho-alveolar carcinoma, lymphoma) (10,11).

In the present case, the main differential diagnoses were: bacterial or viral pneumonia due to COVID-19, alveolar hemorrhage given the context of hemoptysis. Finally, it was an alveolar hemorrhage resulting from an artery embolism. The unilaterality, uni or multifocal, peripheral ground-glass opacity predominantly in the lower lobes, was described in 93% of subclinical patients, during the first week after the onset of symptoms in . The thrombotic situation is correlated to inflammation caused by SARS-CoV-2. The coagulopathy associated with COVID-19 is different from conventional sepsis (13) .

In order not to delay the diagnosis of a pulmonary embolism whatever its origin, performing thoracic CTA in advance remains a real challenge for emergency physicians and radiologists (14). An advice paper from the European Society of Radiology (15) suggests that contrastenhanced CT should be more widely used when assessing patients with COVID-19 pneumonia, especially in those with marked elevation of D-dimers. In our case, this recommendation has been applied. All molecular, parasitic, and serological investigations were strictly normal in our patient with a favorable response after introducing anticoagulant and corticosteroid therapy.

The discovery of ground-glass opacity in a patient with respiratory symptoms, especially in this period of the pandemic, leading to possible COVID-19 pneumonia diagnosis in the early stages, should not omit other causes of ground-glass opacities. A contrast-enhanced CT chest is recommended at the beginning to identify a distal artery embolism before molecular RT-PCR's confirmation. Ground-glass opacities can have many etiologies resulting from interstitium aggression. In our case, it was an alveolar hemorrhage resulting from artery embolism. 

Yanqing Fan, ChuanshengZheng. Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: a descriptive study

Diagnostic performance of CT and reverse transcriptase polymerase chain reaction for coronavirus disease 2019: a metaanalysis

Automatic Detection and Quantification of Ground-Glass Opacities on High-Resolution CT Using Multiple Neural Networks: Comparison with a Density Mask

Ground Glass Opacities of the Lungs as a Predictive Factor in Acute Paraquat Intoxication

CT differential diagnosis of COVID-19 and non-COVID-19 in symptomatic suspects: a practical scoring method

COVID-19 and acute pulmonary embolism: what should be considered to indicate a computed tomography pulmonary angiography scan?

Pulmonary embolism in patients with COVID-19 pneumonia

Figure 1: axial (a) and coronal (b) section lung window of CT-chest angiography showing a peripheral subpleural ground-glass opacity in the lower segment of right lung