Abstract:
Metastatic tumors to the heart include lymphomas, sarcoma, leukemia, and
melanoma. Of these, metastatic melanoma is the most common, and are
usually hematogenous, where metastatic lesions can be present in the
left ventricle, right atrium, and/ or the right ventricle. We present an
atypical metastatic melanoma pattern, where cardiac metastasis
originated by direct extension from the adjacent gastric mesentery. We
also present our trans-cardiac resection approach, which was the safest
way to access the cardiac metastasis intra-operatively without
disrupting the tumor.
Introduction :
Melanoma is a highly aggressive and unpredictable disease. It can
metastasize to the heart as often as 64% in cases with advanced
disease[1-2] . Other sites of metastasis
include the liver, bone, and brain[3] .
Once metastasis to other organs occur, malignant melanoma is defined as
stage IV, with a poor prognosis. In addition to melanoma, other
metastatic tumors to the heart include lymphoma, sarcoma, and
leukemia[4] . Cardiac metastasis from
malignant melanoma occurs in extensive disease and is a late
manifestation of disseminated disease. Some clinical presentations of
metastatic melanoma to the heart include dysrhythmia, myocardial
dysfunction, pericardial effusion, and heart failure. Long-term survival
depends on various factors such as tumor stage, response to systemic
treatments, surgical options, and pre-existing comorbidities. Therefore,
early diagnosis of cardiac metastasis is desirable, as this could
improve prognosis and could be a necessary step in averting morbidity
and mortality from cardiac failure.
Studies[5] have found that the most
common locations of metastatic melanoma to the heart include the left
ventricle (41.9%), right atrium (35.5%), and right ventricle (19.4%).
In this report, we present a case of an atypical metastatic pattern of
melanoma to the heart, as well as our trans-cardiac approach to surgical
excision.
Case Report :
Our case is a 54-year-old Caucasian male with a history of melanoma,
initially diagnosed in 2006. He was in a motor vehicle accident in 2015,
which led to an evaluation with an abdominal computed tomographic (CT)
scan that showed a liver mass. Upon further evaluation with
fluorodeoxyglucose positron emission tomographic (PET) scan in January
2016, demonstrated abnormal uptake in the caudate lobe of the liver.
After biopsy of two peritoneal lymph nodes and a diaphragmatic lesion
which were positive for metastatic melanoma an extensive abdominal
procedure was planned. The patient was evaluated by ophthalmology, and
dermatology and no cutaneous or ocular source of primary melanoma was
identified. He was started on immunotherapy. In 2017, he underwent
surgery involving resection of the medial liver mass, with a left lobe
hepatectomy, partial right hepatectomy, esophageal gastrectomy (Ivor
Lewis Procedure), cholecystectomy, and retrohepatic Inferior Vena Cava
(IVC) resection. Following the operation, he lost a significant amount
of weight but was otherwise doing well.
In February 2021, he underwent a PET scan which showed a hypermetabolic
lesion at the inferior cavoatrial junction, with no evidence of
additional disease recurrence or progression. He underwent Endoscopic
Ultrasound (EUS) and biopsy, which demonstrated malignant melanoma. He
was referred to cardiothoracic surgery for possible resection. A
transesophageal echocardiogram (TEE) indicated an ejection fraction (EF)
of 66% and confirmed the intraatrial component of the tumor. His
cardiac catherization results were pertinent for luminal irregularities
of the distal left anterior descending, and 30% stenosis of the mid
left anterior descending. Cardiac Magnetic Resonance Imaging (MRI)
showed a right atrial mass at the inferior cavoatrial junction with
possible extra-cardiac extension.
An operation was performed. The patient was placed under general
anesthesia and placed on cardiopulmonary with a single atrial cannula
and cooled to 20 degrees C. Following the removal of the atrial canula,
an incision was made in the atrium along the sulcus terminalis just
below the area of the sinus node down towards the IVC. After the atrium
was opened, the point of adherence to the posterior atrial wall was
identified and resected. The tumor extended by a pedicle into the
mesentery of the gastric pull-up (figure 1 ). The tumor was
completely resected, along with the adjacent heart and mesenteric
tissues. The edges of the atrial tissues were cryoablated to eliminate
any micro-invasion. The circulatory arrest time was less than 40
minutes. Pathologic examination revealed a 1.6 x 1.5 x 0.9 cm and 4.4 x
1.8 x 1.7 cm sized tumor, which was black in color (figure 2 ).
A diagnosis of uveal type of melanoma was suspected.
The patient’s postoperative course was uneventful. He was discharged
from the hospital on the 5th postoperative day and was
referred to oncologic cardiology for continued immunotherapy. He would
return to the clinic in two weeks for post-op follow-up in satisfactory
condition.