Cardiogenic and obstructive shock: primary laryngeal synovial sarcoma with cardiac metastasis

Abstract

A man in his 20s with a history of laryngeal synovial sarcoma presented with dyspnoea. Imaging revealed a large right ventricular (RV) mass, which was resected, and histological analysis indicated synovial sarcoma recurrence. Within 1 month of RV mass resection, the tumour progressed with paratracheal metastasis. The lumen was nearly obliterated, and right ventricular outflow tract (RVOT) obstruction led to rapid deterioration with mixed cardiogenic and obstructive shock. We present a rare case of primary laryngeal synovial sarcoma metastasising to the heart.

Background

Synovial sarcoma is a rare, highly aggressive soft tissue malignancy that accounts for 5–10% of soft tissue sarcomas. Synovial sarcomas have the chromosomal translocation t(X;18)(p11.2;q11.2), which fuses the SS18 gene from chromosome 18 and SSX1, SSX2 and SSX4 genes from chromosome X.¹ The age-adjusted incidence of synovial sarcomas is 1.42/1 000 000 in adults and 0.81/1 000 000 in children.² They typically arise from the extremities, but about 7% of synovial sarcomas are located at the head and neck.³ Arising from the larynx and heart is even less common. Given the rarity, knowledge of the most effective management is limited with variability in clinical approach. We discuss the challenges associated with management of rapidly growing, aggressive cardiac tumours.

Case presentation

We present a man in his 20s with a history of primary laryngeal synovial sarcoma, previously diagnosed as high-grade 4.3 cm T2N0 in the left paraglottic region with biphasic morphology and showing SS18 rearrangement by flourescence in situ hybridization (FISH). The patient received induction chemotherapy with doxorubicin for five cycles (total cumulative dose 375 mg/m²) plus ifosfamide for six cycles and adjuvant radiation. He declined surgery at the time and was seemingly lost to follow-up. Eight years after initial diagnosis, the patient presented to the emergency department with dyspnoea and was found to have a left laryngeal mass extending into the thyroid gland, measuring 6.7 cm × 3.5 cm × 4.2 cm. He was managed with a tracheostomy and percutaneous endoscopic gastrostomy tube placement, as well as four doses of liposomal doxorubicin. Five months later, incisional biopsy of the pyriform sinus tumour identified synovial sarcoma with immunohistochemical profile of tumour cells positive for BCL2, CD99 (weak), EMA (focally), AE1/3 and weak S100, as well as grading synovial sarcoma+3, mitotic activity+2 and necrosis+1 resulting in grade 3/3. This was followed by total laryngectomy, total pharyngectomy, total thyroidectomy, bilateral selective neck dissections,^2–4 right anterolateral thigh free flap with microvascular anastomosis to the right transverse cervical artery and right external jugular vein. Pathology revealed grade 3 synovial sarcoma with necrosis and immunohistochemical profile positive for TLE, with negative lymph nodes of the neck (figures 1 and 2).

Figure 1.

Laryngeal tissue with H&E-stained slide of synovial sarcoma. (A) Low power. (B) Medium power. (C) High power.

Figure 2.

Laryngeal tissue. (A) H&E-stained slide of synovial sarcoma with necrosis. (B) H&E-stained slide with invasion into perithyroid tissue. (C) Immunohistochemical stain with TLE1 positive.

One year following local resection, the patient presented to the emergency department with chest pain and shortness of breath. He was found to have a new intracardiac mass obliterating the right ventricle with left ventricular ejection fraction (LVEF) of 35% and a new mass in the right medial lung base measuring 6.7 cm × 4.9 cm × 5.4 cm. The patient underwent palliative debulking of the RV tumour, evacuation of a right haemothorax and closure of a patent foramen ovale. Pathology of biopsied tissue was consistent with synovial sarcoma in five of five samples, forming the diagnosis of Stage IV laryngeal synovial sarcoma with cardiac metastasis (figure 3). Immunohistochemical profile was positive for cytokeratin AE1/AE3 focally (figure 4). FISH was positive for SYT translocation.

Figure 3.

Right ventricular tissue with H&E-stained slide of synovial sarcoma. (A) 40 x power. (B) 100 x power. (C) 200 x power.

Figure 4.

Right ventricular tissue. (A) Gross tumour. (B) Immunohistochemical stain with AE1/AE3 positive.

One month postresection, the patient presented to the emergency department with dizziness, syncope, intermittent pleuritic chest pain, dyspnoea and failure to thrive. Physical exam was significant for hypoxia with an oxygen saturation of 90% on 4 L oxygen via tracheostomy collar, respiratory rate of 18 breaths per minute, blood pressure 100/70 mm Hg, pulse 70-80 beats per minute and afebrile. Breath sounds were diminished, heart sounds S1 and S2 were normal on auscultation and extremities cool to touch bilaterally.

Investigations

Initial workup revealed prerenal acute kidney injury (Cr 1.71, FENa 0.7%), anaemia with haemoglobin 113 g/L, troponin 0.014 ng/mL and brain natriuretic peptide 296.3 pg/mL. ECG showed normal sinus rhythm, with T wave inversions in leads V1–V3. Arterial blood gas was without acid-base disturbance. Chest radiograph demonstrated a moderate right pleural effusion, widened mediastinum and enlarged heart. A CT angiogram of the chest was performed (figures 5 and 6) showing increase in size of the RV mass measuring 6 cm, nearly obliterating the RV lumen with RVOT obstruction. The mass invaded the RV wall, main pulmonary artery and right mediastinum, and there was a new paratracheal mass with patent trachea and mainstem bronchi. It also revealed a small filling defect in the lingular subsegmental pulmonary arteries consistent with pulmonary embolism. Echocardiogram (figures 7 and 8, video 1) revealed paradoxical septal motion, diffusely hypokinetic left ventricle (LV), severe LV systolic dysfunction with a LVEF of 25–30% and severely hypokinetic right ventricle. The intracardiac mass occupied nearly the entire right ventricle, with mild functional pulmonic stenosis from the mass and moderate posterior pericardial effusion observed. Many bubbles were seen crossing into the left atrium, consistent with an interatrial shunt.

Figure 5.

CT angiography chest with contrast. Right intraventricular mass extending into the right atrium and main pulmonary artery, consistent with known history of malignancy. Soft tissue mass extending into the right mediastinum. Known history of prior right ventricular tumour debulking and patent foramen ovale closure.

Figure 6.

CT angiography chest with contrast. Coronal section showing large right ventricular mass invading into the right ventricular outflow tract and involving the tricuspid valve.

Figure 7.

Transthoracic echocardiogram. The right ventricle is dilated. A large mass is seen filling the right ventricle.

Figure 8.

Transthoracic echocardiogram. Long axis view showing the mass extending into the right ventricular outflow tract and the pulmonic valve.

Video 1. Transthoracic echocardiogram. The right ventricle is severely hypokinetic. The left ventricle is diffusely hypokinetic with severe systolic dysfunction. Agitated saline contrast was injected into a peripheral vein. A large amount of bubbles were seen crossing into the left atrium consistent with an interatrial shunt, likely a patent foramen ovale.

bcr-2023-257431supp001.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2023-257431.video01

With worsening respiratory status, repeat chest radiograph demonstrated white out of the right lung. Point of care ultrasound showed significant atelectasis of the right lung and moderate right-sided pleural effusion with loculations. Evaluation with bronchoscopy revealed 90% extrinsic compression of right mainstem bronchus posteriorly and complete collapse of the right lung secondary to metastasis.

Differential diagnosis

Differential diagnoses included postoperative RV dysfunction, recurrence of RV tumour with right heart dysfunction, recurrence of RV tumour with left heart dysfunction, lung parenchymal metastasis, mediastinal metastasis, malignant pericardial effusion, malignant pleural effusion, infection, pulmonary embolism and acute coronary syndrome. There was lower suspicion for anthracycline-induced cumulative cardiotoxicity given that the presentation was 8 years post-treatment.

Treatment

In the emergency department, oxygen supplementation was increased to high flow via tracheostomy at a rate of 15 L/min with FiO2 70% for hypoxia. The patient was admitted to the intensive care unit and was started on a heparin drip for acute pulmonary embolism. Consultations from cardiology, cardiothoracic surgery, medical oncology, radiation oncology and palliative care services were arranged. The patient was deemed a poor surgical candidate given the extension of the mass into the RV wall with risk of perforation and poor prognosis. After multidisciplinary discussions with the patient, the decision was made to pursue palliative chemotherapy. The patient’s oncologist prescribed a 3-day course of ifosfamide with mesna support. Additionally, prophylaxis for tumour lysis syndrome was administered. Radiation oncology services deferred treatment until the patient was in stable condition.

Outcome and follow-up

Over the course of his short admission, the patient developed hypoxic respiratory failure that rapidly progressed, and he required increasing amounts of supplemental oxygen and eventual mechanical ventilation. This was followed by metabolic encephalopathy and shock. The patient passed away 1 week from admission from multiorgan failure and progressive respiratory failure. An autopsy was not performed.

Discussion

Cardiac metastasis of synovial sarcoma is reported in a few cases in the literature. To our knowledge, none of these were from primary laryngeal synovial sarcoma.^4–10 A 2021 review of laryngeal synovial sarcomas found 39 total cases in the literature prior to 2018, five of which had local disease recurrence, as with this case, and two with metastasis, but neither with cardiac metastasis.¹ We believe the local tumour invasion in the right ventricle caused recurrent interatrial shunt and pericardial effusion. The diffuse LV dysfunction may be attributed to RVOT obstruction leading to reduced LV preload, inflammation and hypoxia. Given the lack of wall motion abnormalities and 8-year time span between chemotherapy and LV dysfunction with cumulative dose <550 mg/m², coronary artery disease and anthracycline-induced cardiotoxicity are lower on the list of differential diagnoses.

Synovial sarcomas are known to be aggressive in nature, with a median overall survival of 138 months,³ which is longer than this patient’s course of 110 months. The 5-year survival rate of head and neck synovial sarcoma is 70.5% and 32.9% for thoracic synovial sarcoma.³ The overall 5-year survival rate of primary synovial sarcoma with metastasis is 19.6%.³ Given poor prognosis, early palliative care is integral.

There are no clinical guidelines in place in terms of diagnostic and therapeutic approaches for laryngeal synovial sarcoma. Currently, surgical resection with wide local excision remains the first-line therapy, with chemoradiation often used as an adjunct. In a systematic review of laryngeal synovial sarcoma cases over the past 40 years, a total of 39 patients were reviewed, all of whom underwent surgical resection with or without chemoradiation. Due to the small sample size, overall differences in survival and recurrence rates were unable to be determined when adding radiation or chemotherapy.¹ This highlights the need for standardised treatment guidelines.

Conclusion

We describe the first documented case of cardiac metastasis of laryngeal synovial sarcoma complicated by rapid recurrence, making treatment extremely challenging and prognosis poor.

Learning points.

• Although rare, synovial sarcoma, even primary laryngeal synovial sarcoma, may metastasise to the heart.

• Cardiac metastasis of synovial sarcoma may rapidly grow.

• Cardiac metastasis of synovial sarcoma with surgical management may rapidly recur, even within 1 month of surgical management.

• Rapid follow-up and close monitoring with possible palliative chemotherapy should be discussed after surgical management of synovial sarcoma with cardiac metastasis.

Ethics statements

Patient consent for publication

Consent obtained from next of kin.