Fulminant regrowth of primary pulmonary artery angiosarcoma following pulmonary endarterectomy with tumor resection, identified within nine days of surgery

ABSTRACT Primary pulmonary artery angiosarcoma (PAAS) is an exceptionally rare and aggressive malignancy often misdiagnosed as pulmonary thromboembolism (PTE). PAAS typically exhibits aggressive biological behavior, with rapid local invasion, early recurrence, and distant metastasis, and the prognosis of PAAS remains extremely poor. We report the case of PAAS initially misdiagnosed with PTE, demonstrating its rapid postoperative recurrence within days after tumor resection and aggressive progression with pulmonary and systemic metastases. This case underscores the importance of avoiding misdiagnosis as PTE, which may delay definitive treatment and facilitate disease progression. It also highlights how rapidly residual tumor cells can proliferate and serves as a reminder to carefully consider the potential role of systemic therapy in PAAS management.