A case of constrictive pericarditis caused by pericardial metastasis from laryngeal cancer was diagnosed by echocardiographyFangzhou Guo Fang NieDepartment of Ultrasound Medicine Center, Lanzhou University Second Hospital, Lanzhou, ChinaCorrespondence: Fang Nie (ery_nief@lzu.edu.cn)Key Clinical MessageUnexplained bilateral lower extremity edema in patients with a history of laryngeal cancer should prompt consideration of constrictive pericarditis(CP) from rare pericardial metastasis, with transthoracic echocardiography(TTE) as a valuable diagnostic tool.Keywords:laryngeal cancer,distant metastasis, constrictive pericarditis,echocardiography,case reportIntroductionLaryngeal cancer is one of the most common primary malignant tumors in the head and neck region. In laryngeal cancer, squamous cell carcinoma accounts for 85% to 95% of cases. It is often accompanied by lymph node metastasis at the early stage of diagnosis, so the recurrence rate is extremely high; most of them present with local recurrence and cervical lymph node recurrence. The incidence of distant metastasis is only 3.2%, often metastasizing to the lungs, and lung metastasis accounts for 62.6% of distant metastasis in recurrent laryngeal cancer[1].Distant metastasis involving the cardiac pericardium secondary to laryngeal cancer is rare, with few reports published both domestically and internationally. Meanwhile, constrictive pericarditis (CP) often caused by such metastasis is associated with high clinical rates of misdiagnosis and missed diagnosis.Transthoracic echocardiography (TTE) and Computed Tomography (CT) are the main examination methods for diagnosing CP. The direct signs of CT include pericardial thickening, often accompanied by calcification. TTE remains the primary diagnostic tool in cardiac centers. Due to TTE’s widespread availability and diagnostic efficacy, this technique often serves as the first-line imaging method in the evaluation and management of CP. TTE can visualize the thickened pericardium and detect hemodynamic changes related to restricted cardiac diastole.Case History/examinationA 70-year-old male patient was referred to our hospital with complaints of bilateral lower extremity edema for 1 months，and underwent radical laryngectomy in an outside hospital 8 years ago, which was diagnosed as squamous cell carcinoma of the glottic Larynx,Fuhrman grade was Moderately and poorly differentiated(Grade II-III) ,and was not further treated。On admission, the physical examination results showed that his blood pressure 106/64 mmHg with moderate hyperthermia of 38.9℃，intermittent claudication, bilateral lower extremity edema, a round hole with a diameter of about 1cm in the throat,and dyspnoea. Serological test results showed no obvious abnormality. Electrocardiogram revealed diffuse ST-segment elevation.A TTE was then performed.TTE revealedleft atrium anteroposterior diameter: 47mm(Figure 1A),the transverse diameter of the right atrium was 48mm(Figure 1B),the left ventricular ejection fraction was 62%, with respiration,ventricular septal shift ,the pericardium was thickened, and the thicker part was about 6mm, the inner diameter of the inferior vena cava was 25mm(Figure 1C),Inferior Vena Cava Collapsibility Index was 0%, prominent hepatic vein expiratory diastolic flow reversals,early diastolic mitral inflow velocity and velocity during active atrial contraction were measured by pulsed wave Doppler at the leaflet tips were 87cm/s ,34cm/s, respectively(Figure 1D).Tissue Doppler imaging from the septal and lateral mitral annulus of the left ventricle 12.4cm/s、11.7cm/s(Figure 1E，F),respectively. tricuspid regurgitation velocity: 284cm/s, Conclusion: CP is more likely to be considered because of biatrial enlargement, pericardium thickening, ventricular diastolic filling was limited, dilatation of inferior vena cava and hepatic vein, and normal left ventricular systolic function. CT demonstrated a thickened pericardium(Figure 2).According to Mayo Criteria,the 3 most important findings, based on independent association with the diagnosis of constriction, were (1) respiration-related ventricular septal shift,(2) preserved or increased medial mitral e’ velocity, and (3) prominent hepatic vein expiratory dia stolic flow reversals[2].Three diagnostic criteria were met in this case.Combined with the history of malignancy, metastatic CP was considered.In summary, TTE can make a definite diagnosis and provide clinical information for further treatment of patients.The written informed consent was obtained from the patient’s next of kin for the use of the clinical data and for the publication of this case report. Considering the retrospective nature of the study and the use of anonymized data, formal ethics approval was waived. All methods were performed in accordance with the Declaration of Helsinki.Differential diagnosisThe differential diagnosis of CP caused by pericardial metastatic tumors includes restrictive cardiomyopathy(RCM),atrial fibrillation(AF),chronic right heart failure,and so on,The common cause of CP is tuberculous infection, and most patients have a history of tuberculosis. The pericardial effusion is mostly benign without tumor cells, and TTE shows significant pericardial thickening. In restrictive cardiomyopathy, there is no significant pericardial thickening, and delayed myocardial enhancement can be seen on MRI delayed enhancement scan (indicating myocardial fibrosis). For atrial fibrillation, the amplitude of ventricular wall motion is irregular and uneven in intensity; TTE shows the disappearance of the A wave in the mitral valve orifice blood flow spectrum, presenting a single peak. Chronic right heart failure is caused by a clear history of chronic obstructive pulmonary disease (COPD), or severe regurgitation due to tricuspid valve lesions, which leads to right heart dysfunction.A comprehensive diagnosis can be made by combining the medical history, echocardiographic features, and hemodynamic status.Conclusion and ResultsThe patient underwent pericardiectomy .The surgery was performed under general endotracheal anesthesia via total median sternotomy,During the procedure,the pericardium was significantly thickened and seriously adhered to the heart. Pathological examination of the excised pericardium revealed evidence of metastasis from laryngeal squamous cell carcinoma.(Figure 3). Immunohistochemical staining showed that the tumor cells were CK5/6(+), P63 (+), P40 (+), P53 (wild-type), and the number of Ki-67 positive cells was 30%.The patient showed significant improvement after surgery and was discharged from the hospital in stable condition.Follow-up 1.5 year after surgery , the patient’s condition was good.TTE can confirm the diagnosis of CP by identifying typical signs such as pericardial thickening and restricted ventricular diastole, and provide a basis for treatment. Meanwhile, it should be noted that for patients with a history of malignant tumors, echocardiographic diagnosis must integrate medical history information to avoid missed diagnosis of rare metastatic CP. In conclusion,TTE is a preferred and key method for the diagnosis, differentiation and treatment outcome follow-up of such diseases.DiscussionCP caused by laryngeal cancer metastasis is extremely rare. Different from previous reports that most patients with cardiac metastases have a poor prognosis, this case had recurrence 8 years after the initial operation and remained in good condition during the 1.5-year follow-up after pericardiectomy, providing new references for the prognosis and treatment of such diseases.Tumors can spread to the pericardium through two pathways: (1) lymphatic spread to the pericardium and (2) direct invasion from tumors or lymph nodes[3]. In a previously reported case, the pericardial tumor was thought to result from direct invasion[4]. Our case was characterized by an approximately 8-year recurrence interval and the absence of other systemic metastases. Since lymphatic spread typically leads to systemic dissemination (involving multiple organs), while direct invasion tends to cause local progression without widespread metastasis, and considering the similarity between our case and the previously reported direct invasion case, it is highly likely that the tumor cells invaded the pericardium directly. Additionally, a long recurrence interval may reduce the invasiveness of metastatic lesions—this could be related to decreased proliferative activity of tumor cells over time, creating favorable conditions for surgical intervention.For patients with a history of malignant tumors, especially those under long-term follow-up after laryngeal cancer surgery, unexplained cardiovascular symptoms should prompt prioritization of TTE to evaluate the pericardium. Notably, CP caused by laryngeal cancer metastases was not initially considered in the echocardiographic diagnosis of our case, highlighting the need to integrate the patient’s malignant tumor history with TTE findings to avoid missed diagnoses.Author contributionsSupervision: Fang Nie.Writing – original draft: Fangzhou Guo.ReferencesPan Y, Hong Y, Liang Z, Zhuang W. Survival analysis of distant metastasis of laryngeal carcinoma: analysis based on SEER database. Eur Arch Otorhinolaryngol. 2019;276(1):193-201.Welch TD, Ling LH, Espinosa RE, et al. Echocardiographic diagnosis of constrictive pericarditis: Mayo Clinic criteria. Circ Cardiovasc Imaging. 2014;7(3):526-534Kishino T, Kumamoto K, Matsukawa H, et al. Constrictive pericarditis caused by pericardial metastasis from esophageal squamous cell carcinoma: a case report. Int Cancer Conf J. 2022;11(3):172-177.Kushida S, Takekawa N, Mimura T, et al. Constrictive pericarditis caused by a pericardial-occupying tumor due to esophageal cancer. Clin J Gastroenterol. 2014;7(3):243-246.
