# Cardiac Infiltration in Mycosis Fungoides Resulting in Recurrent Tamponade

## TL;DR

A rare case of mycosis fungoides relapse in the heart highlights the need for considering cardiac symptoms in this disease.

## Contribution

This case report identifies the heart as a potential sanctuary site for lymphoma cells in mycosis fungoides.

## Key findings

- A patient with mycosis fungoides experienced recurrent cardiac tamponade due to pericardial infiltration.
- Relapse occurred despite full donor chimerism and reduced immunosuppression.
- Systemic disease relapse followed isolated pericardial involvement after 22 months.

## Abstract

Clinically apparent cardiac involvement in mycosis fungoides (MF) is a rare phenomenon.

A 61-year-old man presented with dyspnea 11 months after allogeneic hematopoietic stem cell transplantation for MF. Echocardiography revealed a large pericardial effusion causing cardiac tamponade. Emergency pericardiocentesis and effusion analysis confirmed disease relapse isolated to the pericardium in the setting of full donor chimerism. Despite reduction in immunosuppression, relapse with cardiac tamponade later recurred. Combined-modality chemotherapy and radiotherapy was administered. Systemic disease relapse occurred 22 months after isolated pericardial relapse.

This unique case of life-threatening isolated cardiac involvement in relapsed MF exposes the heart as a potential sanctuary site that may sequester lymphoma cells from systemic therapies and the graft-versus-lymphoma effect. Optimal management of this rare complication is unknown.

Pericardial or myocardial infiltration should be considered in patients with MF presenting with cardiac symptoms, conduction disturbance, or shock.