Longitudinal observation of solitary fibrous tumor translation into malignant pulmonary artery intimal sarcoma

BACKGROUND: Pulmonary artery intimal sarcoma (PAIS) is a rare malignant tumor that was usually misdiagnosed as chronic pulmonary thromboembolism. CASE PRESENTATION: We previously reported a solitary fibrous tumor in the pulmonary artery presented with acute pulmonary embolism, which was identified by (99m)Tc-Galacto-RGD(2) imaging. However, this patient had a recurrence in situ two-year after surgery, post-operative pathology revealed pulmonary artery intimal sarcoma. At one-year post-operation, (18)F-FDG PET/CT was performed for exclusion of tumor metastasis, which showed FDG avid lesion in the T5, T10, and L5 vertebral bodies, as well as in bilateral ilium and right ischium. CONCLUSIONS: This is the first longitudinal observation of a solitary fibrous tumor (SFT) development into a pulmonary artery intimal sarcoma (PAIS) and presented with multiple bone metastases.