Case Report: Cardiac Multiple Thrombus and Pulmonary Embolism Associated With Mycoplasma Pneumonia Infection in a Child

Clinical features of intracardiac thrombotic complication in patients with severe Mycoplasma pneumoniae pneumonia

BACKGROUND

Intracardiac thrombus (ICT) is the rarest yet most severe complication of severe Mycoplasma pneumoniae pneumonia (SMPP) in children. This study aims to elucidate the clinical characteristics of patients with SMPP-related ICT.

METHODS

We retrospectively enrolled 68 children with SMPP (18 cases of ICT, 50 cases of non-ICT) who were admitted from January 2014 to January 2024. We compared their demographic data, clinical symptoms, laboratory tests, imaging findings, treatment strategies, and prognoses. Additionally, we summarized data from 33 confirmed SMPP-related ICT cases reported in 12 references.

RESULTS

In our cohort, the ICT group exhibited higher incidences of tachypnea, chest pain, inflammation, and elevated D-dimer levels. They also presented more severe radiological findings and had longer hospital stays compared to the non-ICT group. The chordae tendineae-attached was the most common type (61.1%). Pathological examinations revealed ICT sizes ranging from 480 to 31,500 mm³. A favorable prognosis was observed in 94.4% of ICT patients. Clinical features did not significantly differ between various ICT types. In the overall cohort (51 cases), the right ventricle was the predominant location (68.6%). Notably, 66.7% of patients had concurrent extracardiac thrombosis, with pulmonary thrombosis being the most common subtype (41.2%).

CONCLUSIONS

The clinical characteristics of SMPP-related ICT are non-specific, often coexisting with severe pulmonary lesions and significantly elevated inflammatory markers. All ICT types were chordae tendineae or wall-attached, rather than mobile. These findings suggest that an inflammation storm induced by SMPP may play a significant role in the pathogenesis of in situ thrombosis within the heart and major blood vessels.

Pulmonary embolism in children with mycoplasma pneumonia: can it be predicted?

PURPOSE

To investigate the clinical characteristics of Mycoplasma pneumoniae (MP) pneumonia (MPP) combined with pulmonary embolism (PE) in children.

METHODS

291 hospitalized pediatric cases with MPP were enrolled from January 2018 to May 2024 and divided into the PE group (141 cases) and non-PE control group (150 cases). Clinical data of both groups were analyzed and compared.

RESULTS

C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), and interleukin 6 (IL-6) were significantly higher in the PE group than in the non-PE control group. There were 85 males and 56 females in the PE group. The PE group has male-to-female ratio of 3: 2,and hemoptysis was observed in 11 children (7.08%), chest pain in 29 children (20.60%), and pulmonary necrosis in 89 children (63.12%). In the receiver operator curve(ROC), the areas under the curve(AUC) for D-dimer, CRP, IL-6, and LDH were 0.964, 0.690, 0.632, and 0.765, respectively. In the ROC curve, the cutoff values for D-dimer, CRP, IL-6, and LDH were 0.8 µg/ml, 24.2 mg/L, 37.8 pg/ml, and 461 U/L, respectively.

CONCLUSION

A proportion of children with MP infection combined with PE show atypical clinical symptoms. Children with MPP and elevated D-dimer levels, IL-6, CRP, erythrocyte sedimentation rate (ESR), and LDH may be prone to develop PE.

Pulmonary thromboembolism due to Mycoplasma pneumoniae in children: a case report and literature review

BACKGROUND

Mycoplasma pneumoniae (MP) is a common respiratory pathogen in children that can sometimes lead to extrapulmonary manifestations. Among these, pediatric pulmonary thromboembolism (PE) is clinically rare but carries significant implications. However, it is often underrecognized, and its diagnosis and treatment are not well understood.

CASE PRESENTATION

We report a case of PE associated with MP pneumonia in a 6-year-old girl who presented with recurrent hyperpyrexia, cough, extensive consolidation in the upper lobe of the left lung, and pulmonary artery thrombi in the right lung. Following prompt diagnosis of PE and appropriate antibiotic therapy combined with anticoagulation treatment, the child recovered well and remained healthy at follow-up. The diagnostic and treatment processes were analyzed, and previously reported cases of pediatric MP-related PE were reviewed.

CONCLUSION

PE should be considered in pediatric patients with MP pneumonia who do not improve or whose condition worsens despite standard therapy. The outcomes of pediatric MP-related PE are generally favorable if prompt diagnosis and appropriate treatment are provided.

The chicken or the egg? Mycoplasma pneumoniae complicated by left ventricle thrombus and anterior myocardial infarction: a case report

Background

Mycoplasma pneumoniae can be associated with extrapulmonary manifestations, including vasculitis, myocarditis, and thrombosis. In rare cases, it has also been implicated in intracardiac thrombus formation.

Case Summary

A previously healthy 25-year-old male presented with worsening abdominal pain, an episode of acute chest pain, new lightheadedness, and gait instability in the setting of M. pneumoniae. Initial blood tests were notable for mild coagulopathy, thrombocytosis, transaminitis, and elevated high-sensitivity troponin. Further, workup revealed systematic emboli to the cerebellum, kidneys, spleen, anterior myocardial infarction, and a left ventricular multilobular mural mass. Due to the unknown composition of the mass with concern for further embolic events, the patient underwent successful surgical excision with the mass ultimately defined as a thrombus. Hypercoagulable workup was notably inconclusive and intraoperative myocardial biopsies revealed organizing infarction without inflammation or healed myocarditis. Post-operative course was complicated by left ventricular dysfunction and acute kidney injury, both with eventual improvement. Patient has remained on guideline-directed medical therapy and prophylactic anticoagulation.

Discussion

We presume that the formation of the ventricular thrombus in this case was a result of transient thrombophilia in the setting of M. pneumonia resulting in coronary obstruction and subsequent myocardial injury. This case underscores the challenge of determining the pathophysiological sequence of events in patients with mycoplasma who develop systemic embolism and the management of a large residual thrombus, particularly in regard to surgical consideration.

Mycoplasma pneumoniae pneumonia-associated thromboembolism with plastic bronchitis: a series of five case reports and literature review

BACKGROUND

Mycoplasma pneumoniae pneumonia is a common respiratory infection among children. However, the occurrence of thromboembolism with plastic bronchitis in association with Mycoplasma pneumoniae pneumonia is extremely rare. This case series presents five cases of children with Mycoplasma pneumoniae pneumonia who developed thromboembolism and plastic bronchitis. The clinical presentation, diagnostic approach, and management strategies are discussed.

METHODS

A retrospective analysis was conducted on medical records from a pediatric hospital. Patient demographics, clinical features, laboratory findings, imaging results, treatment modalities, and outcomes were collected.

RESULTS

The patients in our case series presented with varying degrees of respiratory distress, cough, and fever. Imaging studies revealed evidence of thromboembolism based on pulmonary artery occlusion. Bronchial casts were observed by bronchoscopy. Laboratory tests demonstrated elevated D-dimer levels and fibrinogen degradation products. All patients received a combination of low molecular weight heparin anticoagulation and supportive care.

CONCLUSION

Thromboembolism with plastic bronchitis associated with Mycoplasma pneumoniae pneumonia is a rare but potentially serious complication in children. Prompt recognition and management are crucial for improving patient outcomes. This case series highlights the diverse clinical presentations, diagnostic challenges, and treatment strategies for this unique clinical entity. Further research is needed to better understand the pathogenesis and optimal management of this condition.