Sudden death following endomyocardial biopsy of cardiac metastasis from malignant melanoma

Unexpected diagnosis of metastatic breast carcinoma in an endomyocardial biopsy done for cardiac allograft rejection evaluation

We report a case of a 75-year-old female post orthotopic heart transplantation, who presented to the emergency department with a six-week history of shortness of breath, hand tremor and ultimately delirium. She had lobular breast carcinoma more than 5 years prior to her heart transplant, treated by lumpectomy followed by anthracycline based chemotherapy. The reason for her heart transplant was heart failure that was suspected to be from anthracycline cardiomyopathy, however, her explanted heart actually showed cardiac sarcoidosis. She was placed on long-term immunosuppression with tacrolimus, mycophenolate mofetil and prednisone. Two years after her heart transplant, she underwent bilateral mastectomies for recurrent breast cancer. Her neurological workup, including brain imaging (CT, MRI, LP and EEG) did not show any structural abnormalities, ischemia, mass or neurosarcoidosis as cause for delirium. Tacrolimus was held due to renal dysfunction and hemolytic anemia, and then she developed signs of right heart failure so an endomyocardial biopsy was carried out for suspected allograft rejection. The biopsy did not show any evidence of cellular or antibody medicated rejection; however, it demonstrated infiltration by bland appearing cells with signet ring morphology cells many of which showed intracytoplasmic mucin. The cells were strongly positive with cytokeratins AE1/3, CK7 and mammaglobin. The morphology and immunoprofile were consistent with metastatic lobular breast carcinoma and this was thought to be the cause of her clinical presentation with delirium, hemolytic anemia and renal dysfunction as a paraneoplastic syndrome.

Multimodality Imaging of a Right Atrial Cardiac Mass

Work up of a right atrial mass usually requires multimodality imaging and sometimes a biopsy to affirm histological diagnosis. We present a case of a 74-year-old woman with primary cutaneous melanoma (wildtype BRAF) of the right toe who was found to have a large heterogeneous mass in the right atrium on routine surveillance CT scan. She did not have any cardiac symptoms. Vital signs and physical examination were unremarkable. Cardiac magnetic resonance (CMR) imaging demonstrated a bilobed mass with an intramural component and a mobile blood pool component, with interposed thrombus. Three-dimensional transesophageal echocardiogram (3D-TEE) revealed the mass and its site of attachment on the lateral wall of the right atrium. Given the large size of the tumor and its potential for obstruction of tricuspid inflow, the right atrial mass was surgically resected. Pathology confirmed metastatic melanoma. The patient tolerated cardiac surgery well and was discharged shortly thereafter. In the present case, a large cardiac metastasis was discovered in the absence of clinically detectable disease elsewhere. CMR allowed a comprehensive evaluation of the location, extension, and tissue characterization of the cardiac mass. Transthoracic echocardiogram (TTE) and 3D-TEE allowed assessment of the hemodynamic consequences of this mass and aided in operative planning.