Abstract
Background : Primary pericardial malignant mesothelioma is a highly malignant and rare tumor. We present a case of primary pericardial malignant mesothelioma in an adult male patient and review the relevant literature to extend the understanding of the disease.
Methods: The patient underwent pericardial decortication through the cardiopulmonary bypass, which effectively relieved the clinical symptoms caused by the tumor blockage.
Results: Postoperative pathological diagnosis and immunohistochemistry resulted in primary pericardial malignant mesothelioma. The patient recovered after surgery and was followed up regularly after discharge.
Conclusions: Primary pericardial malignant mesothelioma lacks characteristic clinical and imaging manifestations, invariably resulting in misdiagnosis. Pathological results combined with immunohistochemistry are the gold standard for diagnosis. Surgery is the mainstay of treatment, but the prognosis is extremely poor.
Keywords : Primary pericardial malignant mesothelioma; cardiac surgery; pathological diagnosis; immunohistochemistry; case report
Introduction
Primary malignant pericardial mesothelioma (PPM) is a malignant heart tumor originating in the serous pericardium and is highly invasive1,2. Through the collection of clinical data from a patient with PPM and literature review, the clinical manifestations, diagnostic methods, treatment and prognosis, pathological results and immunohistochemical characteristics of PPM are further discussed to expand the understanding of the disease and improve its diagnosis and treatment.
Case report
A 30-year-old man was hospitalized for dyspnea 1 year ago and initially diagnosed with tuberculous pericarditis. The patient regularly underwent anti-tuberculosis and other related treatments for 6 months and was discharged after symptoms were relieved. Over 50 days, the patient developed cough, sputum production, pronounced dyspnea without obvious causes, and concomitant alcoholic cirrhosis. The patient underwent enhanced computed tomography (CT), which revealed diffuse thickening of the pericardium and nodular changes (Fig. 1). Cardiovascular magnetic resonance (CMR; Fig. 2a,b) confirmed that the pericardium was diffusely thickened and abnormally strengthened, limiting cardiac contraction and extending.the mass along the left ventricular wall with possible invasion of the left heart, and tumor-like lesions were not excluded. Positron emission computed tomography suggested uneven thickening of the pericardium and increased metabolism, with infectious lesions being considered first. The patient received anti-tuberculosis therapy while reducing the burden on the heart and nourishing the myocardium by diuresis. On day 22 of the preoperative preparation, the patient suddenly suffered respiratory failure and was placed on a ventilator for endotracheal intubation. After heart failure and oxygenation indicators improved, pericardial decortication was performed. The patient was placed in a flat recumbent position and monitored intraesophageally by esophageal ultrasound. An anterior median incision of the sternum was made to enter the chest cavity, and examination revealed that the pericardium was thickened and extensively adhered, and the heartbeat was weak.Opening the pericardium longitudinally from the anterior wall of the right ventricle, the pericardium is markedly thickened (about 1.0 cm at the thickest point) and contractures without significant calcification.The visceral pericardium was closely adhered, and the thickened pericardium was carefully separated by gradually peeling up to the root of the aortic, down to the diaphragm, to the left side to the anterior diaphragm nerve, and to the right side to the atrium in the order of the outflowing tract first and then into the tract. The thickened visceral pericardial tissue at the apex of the heart was tightly adhered to the heart and was released where it could not be peeled off. The area of excision and release of the pericardium was approximately 15 cm × 10 cm. Cardiac beats were seen to be significantly strengthened, and central venous pressure was slightly lower than before surgery. The surgery was effective, and the patient was treated in intensive care after surgery and underwent three rounds of artificial liver therapy for liver failure and ventilator-assisted therapy for 8 days. The patient was not treated again for tuberculosis, and did not receive tumor-related treatment owing to liver failure and poor systemic condition. He was discharged from the hospital 44 days after surgery. Postoperative pathological results revealed pericardial fibrous tissue hyperplasia and endothelial cell hyperplasia in the shape of a cord (Fig. 3a,b). Mesothelial cell atypia was not pronounced. Hyperplastic mesothelial cell cords were arranged in some areas, and mucoid degeneration could be observed around them. In the immunohistochemical results, adenoid structural cells were CK(+), EMA (partial +), CK5/6 (+), HBME-1 (+), calretinin (+), WT1 (+), D2-40 (+), CEA(−), TTF-1(−), CK7(+), CK20(-), CDX-2(−), CD31(−), CD34(−), FLi1 (+), p53 (partial+), Vim (+). ), p16(−), GLUT1 (partial +), desmin(−), Ki-67 (approximately 20% +) (Fig. 4a,b,c,d). Histological images combined with marker results resulted in a diagnosis of pericardial-reactive mesothelial cell hyperplasia and pericardial malignant mesothelioma (epithelial-like type).