Successful surgical resection of a metastatic clear cell sarcoma in the heart: a case report

Abstract

Background

Clear cell sarcoma (CCS) is a very rare disease and one with a very poor prognosis. Furthermore, its occurrence in the heart is very rare and past reports are scarce.

Case summary

A 33-year-old man who had undergone left arm amputation due to CCS came to the hospital because a positron emission tomography computed tomography (PET-CT) four years post-amputation showed an accumulation in the heart. The PET-CT with glucose suppression treatment showed fluorodeoxyglucose accumulation in the myocardium between the middle of the anterolateral wall and the papillary muscle of the posterior lateral wall of the left ventricle (LV). Based on the course of the disease up to now, it was considered that the accumulation was most likely metastasis of CCS. Observation of the heart after a median sternotomy revealed a white tone, well-defined lesion in the middle of the anterolateral wall of LV. The tumour on the posterolateral side of LV was not exposed on the surface, but it was palpated and was still recognizable as a firm neoplastic lesion. Because the mass was identified as a sarcoma on intraoperative rapid pathology, we decide to perform a total resection. Both lesions were excised, and pathology revealed a diagnosis of CCS.

Discussion

Clear cell sarcoma is a very rare disease that accounts for <1% of all soft tissue sarcomas, and its occurrence in the heart is even rarer. It requires a combination of many imaging modalities. To our knowledge, this is the first case of CCS in the heart treated with surgical resection.

Introduction

Clear cell sarcoma (CCS) is a rare soft tissue tumour that was first described by Enzinger¹ and accounts for <1% of all soft tissue sarcomas. The prognosis for this disease is poor, a five-year survival rate of 47–54%, a 10-year survival rate of only 33–36%, and more than 50% of these patients develop metastases.^2–4 Its occurrence in the heart is very rare, and there have been no previous reports of its resection. Appropriate diagnosis and pathologic confirmation of cardiac CCS are important.

Summary figure

Case summary

A 33-year-old man was diagnosed with tendinitis due to pain in his left wrist joint, and he was referred to another hospital because his condition did not improve. He was diagnosed with giant cell sarcoma of the tendon sheath and underwent a limbal resection, which led to a diagnosis of CCS and amputation of the left arm. He was referred to our hospital for further examination because the positron emission tomography computed tomography (PET-CT) performed four years and five months later showed an accumulation in the heart. He had no symptoms, and his physical examination did not reveal any abnormalities. His grandfather had pancreatic cancer, but he had no history other than CCS. Blood tests showed a slightly elevated N-terminal pro-brain natriuretic peptide at 98 pg/mL (normal range: 1–55 pg/mL), but high-sensitivity troponin T was normal at 0.009 ng/mL (normal range: 0–0.014 ng/mL) and other laboratory parameters were also normal. Transthoracic echocardiography (TTE) showed that the left ventricle ejection fraction (LVEF) was maintained at 65% and no obvious mass-like structures were noted within the visible range. Contrast-enhanced computed tomography (CT) showed pale areas of low CT values within the myocardium in the middle of the anterolateral wall of the LV [Figure 1A(a)] and between the papillary muscles of the posterolateral wall of the LV [Figure 1B(a)]. Transoesophageal echocardiography (TOE) showed a hypoechoic region within the myocardium in the same area as in the CT, which appeared to be different from the normal myocardium. The border was indistinct, but there was no protrusion of the tumour into the cardiac cavity (Figure 2A). Positron emission tomography computed tomography performed after hypoglycaemic treatment showed intramyocardial fluorodeoxyglucose (FDG) accumulation in the middle of the anterolateral wall of the LV [Figure 1A(b)] and between the papillary muscles of the posterolateral wall of the LV [Figure 1B(b)], suggesting a high possibility of malignancy. Cardiac magnetic resonance imaging (MRI) showed a heterogeneous lesion in the middle to apex of the left ventricular anterior wall [Figure 1A(c, d, e)] and in the base to middle of the inferior lateral wall [Figure 1B(c, d, e)], with indistinct borders and internal heterogeneity, which was different from normal myocardium. Cardiac angiography showed no coronary artery abnormality and no nutrient vessels to the tumour. We suspected CCS metastasis based on the history and considered cardiac biopsy to confirm the diagnosis. However, we did not perform a biopsy because the exact location of the tumour was not clear. Furthermore, since CCS tends to metastasize easily, we were concerned that a biopsy would lead to further metastasis. Although there was no proof that the tumour was CCS, if it was CCS, the treatment plan was based on a total resection. The decision on the treatment plan was difficult because the imaging findings were not fully clear to determine the boundaries of the lesion and he was asymptomatic. After much discussion by the heart team, we finally decided on a policy of surgical resection.

One month later, surgery was performed. After a median sternotomy, the anterior aspect of the heart was observed. A 15 mm large, white tone, well-defined lesion was found ∼1 cm to the left of the left anterior descending artery (LAD) in the middle of the anterolateral wall of the LV. On palpation, it was hard tissue and was considered to be one of the targeted neoplastic lesions. The tumour on the posterolateral wall was not exposed on the surface but was palpated under TOE-guided guidance and was also recognized as a firm neoplastic lesion. After determining that the tumour was resectable, the myocardium was incised along the left side of the LAD from the apex to the mass in the middle of the anterolateral wall, and the tumour was resected at the same site (Figure 3A). Although we were concerned that the boundary of the tumour might be unclear in the pre-operative evaluation, when we actually looked at it with the naked eye, the boundary was clear. We resected it with a margin and submitted it to rapid pathology. The mass in the middle of the anterolateral wall was identified as a sarcoma on intraoperative rapid pathology, and we were confident that it was a CCS. Therefore, we continued with resection and excision of the tumour on the endocardial surface between the papillary muscles of the posterolateral wall. After expanding the visual field and observing the intracardiac cavity, a white, well-defined tumour was identified between the anterior and posterior papillary muscles (Figure 3B). The tumour was enucleated using a scalpel after trimming the surrounding abnormal tendon cords, taking care not to damage the papillary muscles or tendon cords. The margins were measured during the procedure, and all were negative. The same confirmation was done for both masses. Pathological diagnosis revealed zonal or dense infiltrating and proliferating tumour tissue within the myocardial tissue of both lesions. The nucleolus was clear, with some light cytoplasm and no specific sequence, HMB45(+), S-100(+), and based on these findings, the diagnosis of a cardiac CCS was made (Figure 4). The post-operative course went well, and he was discharged 19 days later. He is still doing well, because the resection margins were negative, he did not receive any adjuvant therapy with radiation or chemotherapy. He is being followed up with PET-CT and TOE, and his cardiac function is good, with no recurrence or metastasis at the last follow-up 9 months after surgery.

Discussion

Primary cardiac tumours are rare, <10% of which are malignant, sarcomas being the most common.⁵ Sarcomas account for 65% of malignant adult primary cardiac tumours, and their histopathological subtypes include angiosarcomas, leiomyosarcomas, and others.⁶ Metastatic cardiac tumours are 20–40 times more common than primary cardiac tumours, and melanomas have the greatest propensity for cardiac involvement.^7,8 Clear cell sarcoma is a very rare disease, occurring primarily in the extremities, primarily in the lower extremities, primarily around the ankle, ankle, and knee joints, especially associated with tendons and periosteum.⁹ Although CCS is still a reasonably well-known disease in the orthopaedic field, its occurrence in the heart is rare and has rarely been reported in the past. The mainstay of treatment is extensive resection of the tumour. The beneficial effects of adjuvant chemotherapy and radiation therapy have not yet been fully evaluated.¹⁰ It is unclear whether the present lesion is a metastasis of a previous lesion or a primary lesion. We decided to resect because the lesion was confined to the heart and was not complicated by other organ involvement.

Clear cell sarcoma often metastasizes, and close examination and monitoring of lymph node, abdominal/pelvic, and skeletal metastases with CT, MRI, bone scan, and PET-CT are recommended. In this case, TTE, TOE, contrast-enhanced CT, PET-CT, MRI, and cardiac catheterization were performed. Transthoracic echocardiography is considered the first choice for imaging evaluation of cardiac involvement in patients with suspected metastases. In our case, however, the TTE findings were not specific and could not point to a mass. On MRI, CCS lesions typically seem hyperintense on T1-weighted images and may have heterogeneous signal on T2-weighted and late gadolinium enhancement images.^10,11 In this case, delayed contrast was high signal, T1 mapping was different from normal myocardium, and mildly high signal was seen at T2-weighted, all of which is not consistent with previous literature. Cardiac MRI has been reported to show well-defined nodular lesions, but in this patient, the borders were indistinct. Positron emission tomography computed tomography images processed with glucose suppression allowed us to infer that there were two lesions, one in the middle of the anterolateral wall of the LV and the other between the papillary muscles of the posterolateral wall of the LV, and to compare them with MRI and TOE images. When acquired TOE images were retrospectively reviewed, the lesion area was hypoechoic compared to the normal myocardium. We consider it necessary to be fully aware of this fact and observe adequately with this in mind. The combination of multimodalities is highly effective in non-invasively revealing myocardial lesions and diagnosing CCS.

In summary, our patient had a CCS arising in the heart. Clear cell sarcoma is a rare disease, and even more rare to occur in the heart. This case was examined using multiple imaging modalities, including glucose-suppressed PET-CT and TOE, which ultimately assisted surgical resection and diagnosis of a CCS to treat the patient. It should be kept in mind that CCS can occur in the heart and be treated surgically by a personalized multi-modality imaging approach.

Lead author biography

Dr Ayano Osawa graduated from Hiroshima University, Japan. She currently works as a clinical staff in the Department of Cardiovascular Medicine at Hiroshima University Hospital, Hiroshima, Japan.

Acknowledgements

We thank Hiroshi Ofuji from Philips, Japan, for their technical assistance. We also thank Yasuhiro Nakajima and Hiroshi Sekiya from YD, Ltd for their technical assistance.

Consent: Informed consent was obtained from the patient who participated in this case report. The patient provided consent. He was fully informed of the purpose and potential risks and benefits of participating in the study, as well as their right to withdraw at any time. The patient’s data were handled with strict confidentiality in accordance with institutional guidelines and ethical standards. The authors confirm that written consent for submission and publication of this case report including images and associated text has been obtained from the patients in line with COPE guidance.

Funding: This work was supported by a research grant from the Kondou Kinen Medical Foundation (H.U.).

Data availability

Anonymous data will be shared upon request, and it is subjected to the data protection regulations.

References

Author notes