Malignant fibrous histiocytoma of right atrium

Afifty-year-old male patient was admitted with dyspnoea and cough. Four days before admission, he was episode of dyspnoea, could not prostrate with non-productive cough when he was offered with a gastroscopy examination in a local hospital due to anepithymia. The patient had no history of medication or allergies. However, he had smoked for more than thirty years-sixty cigarettes per day. Chest distress without haemoptysis, pink frothy sputum, apsychia, amaurosis, and fever was developed. The symptoms worsened gradually. On examination at the Department of Emergency, Shenzhen People's Hospital, dyspnoea with jugular vein distension and oedema in his head, neck and thoracic region were discovered. The breathing sounds on both lower lungs were low. His heart rate was 100 beats/min without arrhythmia or murmur. His abdomen was soft without rebound tenderness. His liver and spleen were not palpable. Pitting oedema occurred in both low limbs. Furosemide was given, but the symptoms were not relieved. Blood examination showed: leucocyte count was 17×109/L, blood urea nitrogen 13.6 mmol/L, serum creatinine 1.7 mg/L, lactate dehydrogenase 904 U/L, d-dimer 3810.34 ng/ml, NT-pro-BNP 3376 pg/ml and cTnI and cTnT were negative. Chest X-ray showed nodus shadows in right upper and left middle lung and pleural effusion in both sides. Echocardiogram indicated a dilated right atrium and a tumour obstructing the tricuspid valve and superior vena cava (Figure 1A). Prior to surgery, enhanced computed tomography (CT) scan showed low density in same areas, small amount of pericardial effusion, multiple nodes in both sides of lungs, pleural effusion and atelectasis (Figure 1B). Resection of tumour from vena cava and right atrium was performed and malignant fibrous histiocytoma (MFH) was diagnosed pathologically (Figure 1C). Immunohistochemical tests showed: Vimentin (+), CK (−), SMA (−), S 100 (−), Factor XIIIa (+), HMB45 (−), CD68 (+), Lysozyme (+) and Ki 67 about 40% (+). After the surgery, physical abilities of the patient partly recovered.Figure 1.: Images of the patient. A: Echocardiography showed mass in right atrium obstructing tricuspid valve. B: CT discovered low density area in right atrium, which indicated tumour. C: Oval to fusiform cells with elongated nuclei and unusual cytoplasmic vacuoles were seen under microscope (HE, original magnification ×100).Fifteen days after surgery, paralysis and pain occurred in his lumbar and legs. Dyscinesia happened gradually. Positron emission CT showed irregularly shaped radioactive, high density, areas in the third to tenth body of thoracic vertebra, in appendages and soft tissues around them and intestines as well. Radioactive uptake was detected as high density areas in both upper lungs and both posterior segments of lower lobes. Metastases were resected for improving his living quality. After the surgery, the patient was monitored in ICU. Pathological examination of thoracic vertebra indicated metastatic MFH. The patient discharged with severe heart failure two months after cardiac surgery and lost to follow up. Cardiac tumours are rare1 with prevalence of primary cardiac tumours up to 0.03%, of which about 10% are malignant. In 2001, Okamoto et al2 reviewed forty-six cases with cardiac MFH. We searched PubMed with text words of “malignant fibrous histiocytoma of heart” OR “cardiac malignant fibrous histiocytoma” limited with “case reports” from January 1, 2002 to December 31, 2011, and found another thirty-two cases reported cardiac MFH. By searching the CNKI Chinese paper database from 1979 to 2011, the VIP database from 1989 to 2011 and the Chinese BioMed References database from 1990 to 2011, we found sixteen cases. Two papers were excluded, as translations were not available. The remaining forty-six case reports are reviewed. The mean age was 45.0±17.1 years (from 15 to 80 years). Twenty-six were female. It corroborates Okamoto & Kato's study2 that age and gender are not risk factors. Forty-one were primary cardiac MFH. Dyspnoea was the most common initial symptom, appearing in fifteen cases. Dyspnoea could be very severe and caused by cardiac tamponade, or very light. Tumour in left atrium was more common than other places,2 and twenty-seven of our reviewed patients had their tumour there. Inferior vena cava was usually invaded when the tumour grew in right atrium and MFH appeared in the right heart, mainly in the atrium, which extended to upper and inferior vena cava in thirteen cases. Echocardiography was supposed to be an ideal initial imaging technique. However, it could not clearly delineate the morphological appearance and location of the tumour. Eighteen cases had CT scan with or without MRI scan, which encountered the same problem as echocardiography in diagnosing cardiac MFH.3 Like other tumours, the final diagnosis of cardiac MFH depends on pathology. The pathological types in our review were poly-morphia (26 cases), mucus (3 cases) and giant cell (7 cases). The case we reported was a mucus type. Its pathological feature included more than usual mucosal fluid and less tumour cells: fusiform and stellate cells were scattered in mucosal fluid. New vessels were obvious, which made the tumour look like adipose sarcoma. Inflammatory cells were scattered around the vessels. Ki 67 was about 40% positive, which indicated the tumour in our case was a late stage malignancy. Few studies have reported correlations between pathology and clinical results. However, there was one study indicating a high relationship between expression of P53 protein, proliferation cell nuclear antigen and high accident rate of metastasis of MFH.4 Another study indicated that high expression of P53 and Ki 67 were correlated with high recurrent rate and mortality.5 Thirty-eight patients accepted tumour resection, cardiac transplantation or other surgery. Adjuvant chemotherapy was also applied to patients. Injection of ifosfamide and etoposide was usual for chemotherapy. Other chemotherapy included cyclophosphamide, epidoxorubicin, cisplatin and carboplatin. The prognosis of cardiac MFH remains unfavourable. The survival time has been reported from one month to six years, with mean survival duration of about one year.2 Eighteen patients had died and the conditions of three other patients' were very bad when the reviewed papers were published. Patients died of respiratory failure, heart failure, cardiac shock, ventricular arrhythmia or multiple organ dysfunctions. An outstanding exception was a 32-year-old man, who had cardiac transplant and immunosuppressive regimen combined with short term adjuvant chemotherapy, still surviving seven years after operation. Cardiac transplantation would be a better choice than simply removing tumours before metastasis happened. In fourteen patients, MFH recurred after resection. For the case we reported, metastases had already developed when we first treated him. Resection of MFH in the heart could not improve his symptoms and prognosis, and the surgeons had to choose a palliative surgery for him. We would have liked to examine the gene sequence for this patient; however, the cost was unaffordable and we had to abandon this idea. In short, cardiac MFH is a rare malignant tumour, which could happen at any age. Although dyspnoea is the most common symptom, symptoms are usually nonspecific and cannot indicate the side or location of the tumour. Echocardiography, CT and MRI do not provide accurate delineation of the tumour. Tumour resection with or without adjuvant chemotherapy was the main therapeutic but recurrence rate remained high. Cardiac transplantation seemed to be a better choice for improving the prognosis. Genetic examination, currently unaffordable for clinicians, would be advantageous for diagnosis and guidance of treatment of cardiac malignant fibrous histiocytoma in the future. Acknowledgement: We are sincerely grateful to our patient who suffered so with malignant fibrous histiocytoma, but, none the less, agreed to share his medical records. We also thanked Dr. LI Xin-xue and Dr. LIU Jian-ping from Beijing University of Chinese Medicine for revising the paper.