Clinical course
Electrocardiogram revealed normal sinus rhythm. Echocardiogram in clinic
demonstrated normal left ventricular function and a mass in the anterior
mid right ventricle (RV) that was concerning for thrombus (Figure 2). He
was admitted and started on heparin drip given the echocardiogram
findings and concern for pulmonary embolism. An emergent computed
tomographic (CT) scan of the chest demonstrated bilateral pulmonary
emboli and confirmed the RV thrombus (Figure 3). Doppler of the lower
extremity did not reveal any evidence of deep venous thrombosis. His
dyspnea improved with intravenous heparin and he was discharged home on
subcutaneous low molecular weight heparin given his recent cancer and
evidence of thromboembolism while on apixaban. Two months later, a
PET-CT scan done for surveillance of his cancer demonstrated intense
uptake in RV anterior, free wall and hilar lymph nodes concerning for
metastatic cancer (Figure 4). A cardiac MRI for characterization of RV
mass (Figure 5) clearly demonstrated 2 masses in the RV wall along with
cavitary thrombus. A transbronchial biopsy of hilar lymph nodes was
performed which confirmed the diagnosis of metastatic squamous cell
carcinoma.
Due to widespread metastases he was deemed inoperable and started on
immunotherapy with cemiplimab. Six months after starting immunotherapy,
his RV mass appeared smaller in size.
Repeat PET-CT scan showed persistent hypermetabolic uptake in the RV but
showed full metabolic resolution of the previously demonstrated hilar
lymphadenopathy.
Discussion:
In our case, the patient had curative intent surgery and radiation
therapy for local recurrence of SCC and was believed to be in remission.
He had rapidly worsening dyspnea and CT findings consistent with
pulmonary embolism and it was therefore reasonable to assume that the RV
mass was thrombus. However, subsequent PET-CT and Cardiac MRI showed
metastatic cancer hiding behind the guise of thrombus. Lung, breast,
esophagus and hematologic malignancies are the most common causes of
cardiac metastasis1. Cutaneous SCC results from
malignant growth of epidermal keratocytes and is one of the most common
skin cancers. Local recurrence after curative surgery is uncommon and
occurs in < 5%. Cardiac metastases of cutaneous SCC is
extremely rare and is usually associated with other non-cardiac
metastases.2,3
Mural thrombi in the cardiac cavity can mimic a cardiac mass or mask an
underlying tumor. There are a few case studies of RV tumors initially
misdiagnosed as RV thrombus especially in the setting of pulmonary
embolism. In cases where cMRI was not available, diagnosis was made when
there was no response to thrombolytic therapy and surgical thrombectomy
was performed.4,5 In other cases, cMRI and/or PET
imaging helped disclose underlying malignancy.6,7
While some primary malignancies such as gastric, lung, pancreatic and
brain and certain histologic types such as adenocarcinomas carry a high
risk for thromboembolism, rates of thromboembolism with cutaneous SCC is
low. In one analysis of a large national cohort, the risk of
thromboembolism in patients with cSCC was similar to general
population.8 Pulmonary embolism or RV mural thrombus
in such patients with such low risk for thromboembolism should have
therefore raise suspicion for cardiac metastases. Cardiac tumors can
cause thromboembolism by 2 mechanisms: thrombus formation overlying the
tumor surface and tumor fragmentation.7,9,10
Our case is unique in 2 aspects: 1) metastasis to the heart occurred in
the absence of overt other metastases in a patient with cutaneous SCC
which has a very low potential for cardiac metastasis and
thromboembolism; 2) cardiac metastases was associated with mural
thrombus and pulmonary embolism which created a diagnostic difficulty
and delay. Our case highlights the importance of suspecting metastatic
spread to the heart in such patients with history of malignancy who
present with pulmonary embolism and RV abnormalities. Multimodality
imaging with cardiac MRI, PET-CT can be of immense value in diagnosing
underlying metastatic tumors in patients with ventricular thrombus.
Conclusion: Cardiac metastases should be suspected in individuals with
right ventricular thrombi and known history of malignancy. Multimodal
imaging with PET-CT and cardiac MRI is essential for timely diagnosis.
References:
- Goldberg A, Blankstein R, Padera R. Tumors Metastatic to the Heart.
Circulation. 2013;128:1790–1794.
https://doi:10.1161/CIRCULATIONAHA.112.000790.
- Kondo T, Takahashi M, Kuse A, et al. An autopsy case of right
ventricular cardiac metastasis from squamous cell carcinoma of the
left hand. Egypt J Forensic Sci. 2016;6:509-512.
https://doi.org/10.1016/j.ejfs.2016.05.002
- Efendizade A, Kobayashi D, Forbes TJ, Liu S, Lieberman R, Afonso L.
Myocardial Metastasis of Cutaneous Squamous Cell Carcinoma in a Burn
Patient. CASE (Phila). 2018;3:6-10.
https://doi:10.1016/j.case.2018.09.004
- Gül M, Babat N, Uçar FM, Kuyumcu MS, Özeke O. Massive pulmonary
embolism and a cardiac mass: Thrombus or metastasis? Turk Kardiyol
Dern Ars 2016;44:597-599 https://doi: 10.5543/tkda.2016.77772 597
- Han GH, Kwon DY, Ulak R, Ki KD, Lee JM, Lee SK. Right ventricular
metastatic tumor from a primary carcinoma of uterine cervix: A cause
of pulmonary embolism. Obstet Gynecol Sci. 2017;60:129-132.
https://doi:10.5468/ogs.2017.60.1.129
- Galiuto L, Locorotondo G, Fedele E, et al. Cardiac thrombi mistaken
for metastasis in recurrent melanoma. J Cardiovasc Med. 2015;16 Suppl
1:S29-S30. https://doi: 10.2459/JCM.0b013e3283613967
- Kalvakuri K, Banga S, Upalakalin N, Shaw C, Davila WF, Mungee S.
Metastatic right ventricular mass with intracavitary obliteration. J
Community Hosp Intern Med Perspect. 2016;6:31679.
https://doi:10.3402/jchimp.v6.31679
- Rudy SF, Li K, Moubayed SP, Most SP. Risk of Venous Thromboembolism in
Patients With Keratinocyte Carcinoma. JAMA Facial Plast Surg.
2018;20:453-459. https://doi:10.1001/jamafacial.2018.0331
- Ma G, Wang D, He Y, Zhang R, Zhou Y, Ying K. Pulmonary embolism as the
initial manifestation of right atrial myxoma. Medicine. 2019;
98:e18386 https://doi: 10.1097/MD.0000000000018386
- Porres-Aguilar M, DeCicco I, Anaya-Ayala JE, et al. Cardiac metastasis
from liposarcoma to the right ventricle complicated by massive
pulmonary tumor embolism. Arch Cardiol Mex. 2019;89:279-282.
https://doi:10.24875/ACM.M19000036
Figure legend
1: Chronology chart of events prior to presentation
A timeline of patient’s previous medical history before his presentation
to the cardiology clinic with unexplained shortness of breath.
2. Right heart thrombus on echocardiography
Image of parasternal long axis of the RV anterior wall with contrast
agent showing a non-enhancing mass in the anterior mid right ventricle
suggestive of thrombus (red arrow).
RV=Right ventricle; LV=Left ventricle
3. Right heart thrombus on CTA of the chest
A) Computed tomography angiography (CTA) chest with contrast as viewed
in coronal section demonstrates a filling defect in the lateral
basal-mid right ventricle (red arrow).
B) Computed tomography angiography (CTA) chest with contrast as viewed
in transverse section demonstrates a filling defect in the anterior mid
right ventricle (red arrow).
RV=Right ventricle; LV=Left ventricle; RA=Right atrium
4. Cardiac metastatic disease seen on PET-CT scan
Positron emission tomography- computed tomography (PET- CT) scan shows
two hypermetabolic foci (blue arrows) within the heart corresponding to
filling defects identified on previous chest computed tomography
angiography (CTA) concerning for cardiac metastatic disease.
RV=Right ventricle; LV=Left ventricle
5. RV masses with thrombus on MRI
High resolution late gadolinium enhancement Magnetic Resonance Imaging
(MRI) showing two enhancing masses at the anterior and lateral wall of
the mid right ventricle (blue arrows), suspicious for metastatic
disease. A non-enhancing mass seen in the adjacent basal-mid right
ventricle is a thrombus (red arrow).
RV=Right ventricle; LV=Left ventricle