Pulmonary Arterial Sarcoma With a Wide Range of Endovascular Intima Invasion Microscopically

A 69-year-old man underwent right middle and lower lobectomy for suspected lung cancer (cT3 N1 M0). The final pathologic diagnosis was pulmonary artery (PA) sarcoma. The stump was positive despite having a sufficient surgical margin. After 11 months, we performed completion pneumonectomy and PA resection and replacement under extracorporeal circulation for local recurrence. Although the PA was macroscopically intact, the frozen pathologic diagnosis was positive 3 times. Because PA sarcoma extends microscopically through the intima of the PA, it is difficult to determine the extent of resection on imaging. We consider confirmation by a frozen pathologic diagnosis to be essential.