Not the usual suspect

A 54-year-old lady presented with progressive breathlessness and leg swelling. On admission, there was fluid overload, pyrexia, raised CRP, EBV viremia and proteinuria. A CT scan was performed after echocardiogram demonstrated pericardial fluid and a possible mass. History of hypertension, asthma and renal transplant for end stage renal failure.

Chest radiograph showed globular enlargement of the cardiac shadow and bilateral pleural effusions with bi-basal atelectasis (L>R); no evidence of focal consolidations or pulmonary nodules.

Echocardiogram revealed large circumferential pericardial effusion with a 5 cm echogenic round structure seen posterior to LV and LA. Differentials included soft-tissue mass, organised pericardial effusion or haematoma.

Contrast enhanced CT of the thorax in arterial and venous phases demonstrated a homogeneously enhancing soft-tissue mass in the left atrioventricular groove, lateral and inferior to left atrium with minimal mass effect. No internal calcification or infiltration into the surrounding structures was seen.

There was a large circumferential pericardial effusion with no haematoma. Bilateral pleural effusions were present, left more than right, with associated basal lung atelectasis.

CT images of abdomen and pelvis revealed splenomegaly and normal transplant kidney in right iliac fossa.

No enlarged lymph nodes identified in the neck, chest, abdomen or pelvis.

This was a rare and unusual case of post-transplantation lymphoproliferative disorder (PTLD) presenting as a pericardial mass in a patient with renal transplant. The constellation of imaging findings with clinical background of renal transplants and associated Epstein-Barr virus (EBV) viraemia helped to make this diagnosis.

Pericardial fluid obtained with pericardiocentesis demonstrated atypical plasma cells with neoplastic immunophenotype and no epithelial, mesothelial, melanocytic or germ cell neoplasm. A bone marrow biopsy was also performed which was hypercellular with plasma cells and EBV viraemia.

Unfortunately, this patient succumbed to multiorgan failure secondary to Haemophagocytotic lymphohistocytosis / macrophage activation syndrome.

Background

PTLD refers to abnormal lymphoid proliferations occurring in the setting of depressed T-cell function due to immunosuppressive therapy commonly used after solid organ or stem cell transplantation [1, 2].

The incidence of PTLD is approximately 1 to 3% in organ transplant recipients [1, 2].

Majority are related to EBV infection in about 60 to 70% cases [1, 2].

The anatomic distribution of PTLD is influenced by the allograft itself [1]. However, in our renal transplant recipient, the primary site was the pericardium.

Clinical Perspective

In early stages most patients are asymptomatic and in later stages, clinical manifestations are non-specific and difficult to differentiate from infection or allograft rejection [1].

Our case showed a mixed clinical picture of inflammatory features, fluid overload and early cardiac tamponade.

Imaging, particularly contrast enhanced CT, helps in diagnosis of the lesions, staging and guiding biopsy [1].

Imaging Perspective

CT may show a large focal mass, diffuse soft tissue infiltration, or multiple nodules with homogeneous or heterogeneous enhancement with a predilection for right heart chambers, the atrioventricular groove, and the pericardium with associated effusion [3].

Although PTLD can cause pleural effusions, benign pleural effusions from non-PTLD causes are more common [4].

USS guided pericardiocentesis and analysis of the pericardial fluid can confirm the diagnosis [3].

Outcome

Cardiac PTLD typically follows a clinically aggressive course and prognosis is poor [3] as demonstrated in this case.

Take Home Message / Teaching Points

• PTLD are abnormal lymphoid proliferations that occur in the post-transplantation setting.
• Time of onset is variable from within 1 year to a median of 5 years post-transplantation.
• The majority are related to Epstein-Barr virus infection.
• Clinical presentation is non-specific and imaging helps in making an early diagnosis.
• Diagnosis is only confirmed by positive cells on biopsy / fluid analysis.