A 41-year-old man suffering from the bilateral knee and ankle arthralgia for several months was transported emergently to our hospital owing to acute respiratory distress and hemoptysis. Upon arrival, he was in a shock state. Chest roentgenography revealed severe pulmonary congestion; cardiac echogram revealed a large mass in the LA that incarcerated into the mitral valve. Additionally, chest computed tomography (CT) revealed a tumor in the LA; thus, he was diagnosed with acute left heart failure caused by the mass that obstructed cardiac blood flow (Fig. 1).
An emergency surgery was performed under cardiac arrest with extracorporeal circulation, which was established in the usual manner with bicaval direct cannulation. Because of the dimensions of the tumor and its pedicle attachment, we could approach through both the wall incisions on the right-side LA from the right upper pulmonary vein and atrioseptostomy from the right atrium. The tumor pedicle widely and irregularly originated from the right upper and posterior LA wall and extended to the lateral LA wall, which included the right upper pulmonary vein. The tumor was visibly extirpated and invaded the LA wall (Fig. 2). The shape and function of the mitral valve were intact, and the large defect in the LA wall was reconstructed using a bovine pericardial patch. It was 159 min under extracorporeal circulation, and the aortic cross-clamping time was 123 min.
Extracorporeal circulation weaning and post-operative course were uneventful, and arthralgia in both lower limbs disappeared immediately after surgery. The pathological diagnosis was UPS with clear resection margins (R0 resection), which invaded the atrial muscular layer (Fig. 3). Subsequently, as imaging studies soon and 3 months after surgery did not reveal tumor presence, we decided to adopt a more suitable treatment strategy without involving adjuvant therapy after surgery if UPS relapse or metastasis occurred. Specifically, we planned to perform re-surgical resection or proton radiotherapy for recurred or metastatic tumors. In addition, we planned to initiate systemic chemotherapy using a target organ drug or other anti-malignant tumor agents for distant metastasis depending on the local and general conditions of the patient. He was discharged 20 days after surgery without additional treatment and was able to work 2 months after discharge.
However, local recurrence in the LA was observed on positron emission CT (PET) and other imaging studies 7 months after surgery (Fig. 4a). A tumor was detected on the posterior LA wall adjacent to the incision line of previous surgery. He again experienced arthralgia in both lower limbs. Thus, we selected radiotherapy with proton beam as treatment, and a dose of 75 Gy was delivered to the recurrent tumor in 30 fractions for 45 days. No tumor was observed in the LA on imaging performed 2 months after radiotherapy as an outpatient (Fig. 4b).
After 6 months, the second local recurrence at a different site in the LA and distant metastasis to the left adrenal gland were simultaneously observed on the results of several imaging tests. In the left adrenal gland, a large solid tumor with an irregular surface and abundant blood flow was observed on enhanced CT scan (Fig. 5a), and remarkable fluorodeoxyglucose (FDG) uptake was found on positron emission tomography/CT scan (Fig. 5b). Proton beam radiation for both tumors was selected to conserve the left kidney function. A dose of 60 Gy was delivered to the tumor in 30 fractions in the LA and 46 Gy in 23 fractions in the left adrenal gland. Moreover, chemotherapy with pazopanib hydrochloride (800 mg/day), a tyrosine-kinase inhibitor (molecularly targeted drug), was used in combination radiotherapy. At the end of the second radiotherapy, a larger but cystic and non-enhanced mass in the left adrenal gland was observed on CT (Fig. 5c). While the patient was receiving chemotherapy for 8 months after the completion of the second radiotherapy, the size of the left adrenal mass apparently reduced. Moreover, neither blood flow nor fluorodeoxyglucose (FDG) uptake of lesions in both the LA and left adrenal gland were revealed on positron emission CT scan (Fig. 5d, e).
Twenty-seven months after surgery, no active tumor was noted on any imaging result, and he returned to work without symptoms, including arthralgia of the lower limbs.