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Primary malignant pericardial mesothelioma (PMPM) is an aggressive tumor that originates from the mesothelial cells of the pericardium. PMPM with extensive atrial infiltration and bone metastasis is extremely rare. The diagnosis and staging of PMPM based on anatomical imaging may be difficult when concurrent pericardial and pleural effusions are present. A 28-year-old man presented with progressive chest pain. Concurrent pericardial and pleural effusions were identified on computed tomography. On echocardiography, mild thickening and adhesions of the pericardium with the right ventricle and atrium were observed. 18F-fluorodeoxyglucose (FDG) metabolism imaging revealed increased accumulation in the pericardium and adjacent right atrium. Ring-shaped radioactivity aggregation and bone destruction in the sacrum were demonstrated on 18F-FDG and 99mTc-methyl diphosphonate imaging. The diagnosis of PMPM was subsequently confirmed by pathology. The patient survived for >1.5 years with comprehensive treatment.
Primary malignant pericardial mesothelioma (PMPM) is extremely rare, with an estimated incidence of <0.0017%, as reported in a large autopsy study of ~50,000 cases (
In May 2010, a 28-year-old man was admitted to the Nanjing First Hospital due to progressive left-sided chest pain and breathlessness for 4 months, which had worsened over the last 1 h. The patient had a 10-year history of smoking (1 pack/day). There was no history of tuberculosis or asbestos exposure. Two months prior to admission, the patient had been hospitalized with the same symptoms in another hospital. Physical examination, chest radiography, computed tomography (CT) and enhanced CT revealed widening of the myocardial boundary, concurrent large pericardial effusion and little-to-moderate pleural effusion (
Malignant mesothelioma usually occurs in the peritoneum or pleura, while it rarely occurs in the pericardium. Primary malignant pericardial mesothelioma (PMPM) is an extremely rare occurrence with a low incidence (<0.0022%) and a poor prognosis (
Without a definitive etiology or specific clinical manifestations (
The clinical misdiagnosis rate of PMPM is extremely high due to its non-specific symptoms, ranging from cough, dyspnea and dysphagia to chest pain, as in the present case. The clinical signs are often misdiagnosed as other conditions, such as coronary heart disease, tuberculous pericarditis, atrial myxoma and cardiomyopathy. In the present case, tentative antituberculosis treatment was introduced due to a misdiagnosis based on a positive PPD test. Aspiration and evaluation of pericardial fluid was inconclusive, as it is difficult to differentiate malignant mesothelioma cells from reactive cells.
The characteristic feature of PMPM is focal or diffuse uneven solid growth of the mesothelium, with atypical cavities surrounded by fibrous stroma (
The prognosis of PMPM is extremely poor, with a median survival of ~6 months (
(A) Echocardiogram and (B) chest computed tomography (CT) images (left, unenhanced; and right, enhanced CT scan). Echocardiography revealed thickening of the pericardium and adjacent right ventricle and right atrium. CT images revealed concurrent pericardial and pleural effusion.
18F-FDG images and 99mTc-MDP bone scan images. (A) 99mTc-MDP whole-body scan showing a sacral osteolytic metastasis (arrow) (left, anterior view; right, posterior view). (B and C) Highly increased uptake of 18F-FDG was observed in the right atrium and the pericardium adjacent to the right ventricle and atrium, with mild increase in the inner wall of the thoracic cavity (arrows). (D and E) Ring-shaped radioactivity aggregation and osteolytic bone metastasis in the sacrum were visualized on 18F-FDG coincidence imaging (arrows). B-E: Left panel, CT; middle panel, 18F-FDG PET; and right panel, PET-CT fusion images. FDG, fluorodeoxyglucose; MDP, methyl diphosphonate; CT, computed tomography; PET, positron emission tomography.
Pathology of pericardium and computed tomography (CT) images at 4 months and 1 year after surgical resection. (A) Tissue from the pericardium and adjacent atrium strained with hematoxylin and eosin staining (original magnification: left panel, ×50; and right panel, ×100) revealed diffuse infiltration of the pericardium by epithelioid cells in papillary arrangements. The tumor cells were characterized by abundant cytoplasm, prominent nuclei and cytoplasmic vacuoles. (B) No pericardial effusion and little pleural effusion were observed at 4 months after the operation on contrast-enhanced CT (left panel, lung window; and right panel, mediastinal window). (C) Multiple lung metastases and a large pleural effusion were found at 1 year postoperatively (left panel, lung window; and right panel, mediastinal window).