Left-sided primary cardiac lymphoma diagnosed by needle biopsy with total endoscopic anterolateral mini-thoracotomy: a case report

Abstract

Background

Primary cardiac lymphoma (PCL) is an extremely rare tumour that typically affects the right heart chamber. It is a life-threatening tumour presenting with rapid growth; therefore, early diagnosis and treatment are crucial for improving the prognosis of patients with PCL.

Case summary

An 81-year-old female with a history of dermatomyositis and interstitial pneumonia was referred to the cardiology department for cardiomegaly detected on chest radiography and computed tomography (CT). She experienced shortness of breath on exertion. Electrocardiography revealed negative T-waves in various leads. Transthoracic and transoesophageal echocardiography revealed a large mass on the epicardial free wall of the left atrium and ventricle. Coronary CT angiography showed feeding vessels from the left circumflex artery and the posterolateral branch of the right coronary artery. Positron emission tomography showed elevated mass uptake and no systemic metastasis. Needle biopsy with total endoscopic anterolateral mini-thoracotomy was performed. Histopathological examination revealed diffuse large B-cell lymphoma. She received systemic chemotherapy and achieved a complete metabolic response.

Discussion

Herein, we report an extremely rare case of PCL located on the left side of the heart. Owing to the location of the tumour, percutaneous or transcatheter biopsy could not be performed. Early diagnosis with needle biopsy via anterolateral mini-thoracotomy and systemic chemotherapy resulted in good outcomes.

Introduction

Primary cardiac lymphoma (PCL) is a rare cardiac tumour that accounts for <2% of all primary cardiac tumours.¹ It typically involves the right cardiac chambers.² The overall prognosis is poor, with a median survival of <1 year after diagnosis. Early diagnosis and treatment initiation are important to improve the prognosis of patients with PCL. We present a rare case of left-sided PCL diagnosed by needle biopsy with total endoscopic anterolateral mini-thoracotomy and treated successfully with systemic chemotherapy.

Summary figure

Case presentation

An 81-year-old female patient was referred to the cardiology department because of cardiomegaly on chest radiography (Figure 1A) and non-contrast computed tomography (CT) (Figure 2A). She had a 12-year history of dermatomyositis and interstitial pneumonia that were controlled with cyclosporine (125 mg/day). She reported shortness of breath on exertion. Her physical examination results were normal, except for fine crackles in the lower lung fields. Electrocardiography showed sinus rhythm with various abnormalities including negative T-waves in leads I, II, III, aVL, aVF, and V2–6 (Figure 1B). Transthoracic echocardiography and transoesophageal echocardiography revealed a heterogeneous hypoechoic tumour attached to the epicardial free wall of the left atrium and ventricle with a diameter of 83 × 56 mm (Figure 3A and B). No pericardial effusion or haemodynamic impairment was observed. Colour Doppler imaging revealed feeding vessels within the mass (Figure 3C). A laboratory analysis revealed elevated levels of soluble interleukin-2 receptor (1034 U/mL; reference values, 122–496 U/mL), β2 microglobulin (3.3 mg/L; 0.6–1.6 mg/L), N-terminal pro-brain natriuretic peptide (209 pg/mL; 0–125 pg/mL), and sialylated carbohydrate antigen KL-6 (573 U/mL; 0–499 U/mL). Cancer antigen 19–9 (58.0 U/mL; 0–36.9 U/mL), cancer antigen 125 (45.7 U/mL; 0–34.9 U/mL), squamous cell carcinoma antigen (1.5 ng/mL; 0–1.2 ng/mL), and cytokeratin 19 fragment (3.6 ng/mL; 0–2.0 ng/mL) levels were slightly elevated. Electrolyte levels and complete blood counts were normal, and serological screening tests for human immunodeficiency virus, hepatitis B virus, and hepatitis C virus showed negative results. Whole-body contrast-enhanced CT revealed no early contrast enhancement, whereas an inhomogeneous contrast enhancement was observed in the delayed phase (Figure 2B and C). No lymph node enlargement or other tumour lesions were observed. Coronary CT angiography showed feeding vessels from the left circumflex artery and the posterolateral branch of the right coronary artery (Figure 2D). ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET) showed increased uptake of the mass, with a maximum standardized uptake value of 12.8, consistent with a malignant rather than benign mass (Figure 4A and B). No other lesions with abnormal uptake were observed, indicating metastasis. Bone marrow tests did not reveal tumour invasion. Although malignant lymphoma or lymphoproliferative disorders were suspected from above examinations, a pathological examination was required for a definitive diagnosis. Considering the tumour location, a needle biopsy with total endoscopic anterolateral mini-thoracotomy was performed. Under general anaesthesia, a double-lumen endotracheal tube was inserted for right single-lung ventilation. In a supine position with 30° elevation of the left side, a 5-cm skin incision was made in the fourth intercostal space at the left anterior axillary line. An 11-mm camera port was inserted through the fourth intercostal space in posterior side of the skin incision, and a 5-mm additional working trocar port was inserted through the sixth intercostal region at the anterior axillary line. Meanwhile, bilateral femoral veins were exposed for venovenous extracorporeal membrane oxygenation (VV-ECMO) in case hypoxaemia occurred, because her spirogram demonstrated reduced respiratory function due to interstitial pneumonia. The pericardium was opened longitudinally, and the tumour was exposed. It was soft and had irregular surface with relatively clear boundary (Figure 5A). Pericardial effusion was a little and serous. The tumour was punctured with a biopsy needle twice, and adequate tissue specimens were obtained. Although mild hypoxaemia occurred before the needle biopsy, bilateral lung ventilation was used temporarily and she tolerated without the use of VV-ECMO. A 19-Fr chest drain was inserted through the trocar port site, the pericardium and the wound were closed, and the procedure was completed. Histopathological examination of the mass showed moderate-to-large malignant lymphoid cells with high nuclear-cytoplasmic ratios on haematoxylin and eosin staining (Figure 5B and C). Immunohistochemistry results were as follows: CD20+, CD3-, CD5-, CD10-, Bcl6-, MUM1+, and EBER+ (Figure 5D and E); these results were consistent with a diffuse large B-cell lymphoma (DLBCL) of non-germinal centre phenotype. The patient did not have B symptoms and the international prognostic index was 2 (age, 81 years; Performance Status, 2). She received systemic chemotherapy with a combination of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-mini-CHOP), and 1-month follow-up transthoracic echocardiography and ¹⁸F-FDG-PET revealed tumour regression (Figure 4C and D). After completing six cycles of chemotherapy, the patient achieved complete remission and is still alive more than one and a half years after the initial diagnosis.

Discussion

Primary cardiac lymphoma is defined as an extranodal lymphoma involving only the heart and pericardium.³ It is rare and accounts for only 1.3% of all primary cardiac tumours and 0.5% of all extranodal lymphomas.¹ The most affected chamber is the right atrium, followed by the right ventricle, left atrium, and left ventricle.² Left-sided PCL, as in the present case, is exceedingly rare and accounts for only 7% of all PCL cases. It must be differentiated from more common cardiac tumours such as myxomas (the most common benign tumour) and angiosarcomas (the most common malignant tumour). Multimodality imaging is helpful in determining the characteristics of cardiac masses. Echocardiography is the most frequently used imaging method. It can evaluate the location, size, shape, and mobility of these masses as well as their relationships to adjacent structures and haemodynamic influence. Computed tomography and ¹⁸F-FDG-PET can help detect extracardiac disease and confirm whether a tumour is benign or malignant. The PCL appears hypoattenuated or isoattenuated relative to the adjacent myocardium and demonstrates heterogeneous contrast enhancement on CT.⁴ Increased uptake of ¹⁸F-FDG indicates malignancy with a relatively high sensitivity and specificity.⁵ Although current multimodality imaging procedures provide extensive information, histological examination is required for a definitive diagnosis. Histological assessments usually involve echocardiography- or CT-guided biopsy with an endovascular or percutaneous approach, but these techniques were not possible in our case because of the unusual location of the tumour and the lack of extracardiac involvement. In such cases, surgical biopsy is required. However, cardiac surgery through standard median sternotomy is very invasive, particularly in elderly patients. On the basis of these considerations, we decided to perform needle biopsy with anterolateral mini-thoracotomy. Surgical resection was not performed because complete resection of the mass was impossible and had not been reported to improve prognosis if the tumour was actually lymphoma as indicated by preoperative examinations.² Primary cardiac lymphoma is a life-threatening tumour with rapid and aggressive growth if not treated early and properly. The median overall survival was <1 year.² Chemotherapy is the only effective treatment for this condition. Primary cardiac lymphoma is typically a subtype of non-Hodgkin B-cell lymphoma, most often DLBCL, and is highly sensitive to rituximab-based chemotherapy. We chose reduced-dose chemotherapy (R-mini-CHOP), which is a safe and effective treatment regimen for elderly patients.⁶ Although the overall response rate to chemotherapy is 79–87% and our patient achieved a complete metabolic response, close observation is needed because the recurrence rate was as high as 55%.⁷

Conclusion

Early diagnosis and treatment are important for patients with PCL. A needle biopsy with anterolateral mini-thoracotomy can be an option for definitive diagnosis of PCL located on the left chamber of the heart.

Lead author biography

Madoka Sano graduated from Gifu University in Japan. She is working as a staff cardiologist at Kobe City Medical Center General Hospital in Japan. She is interested in the areas of echocardiography and heart failure.

Acknowledgements

We would like to thank Editage (www.editage.com) for English language editing.

Consent: The authors confirm that written consent for submission and publication of this case report, including image(s) and associated text, has been obtained from the patient in line with COPE guidance.

Funding: None declared.

Data availability

The data underlying this article will be shared on reasonable request to the corresponding author.

References

Author notes