A group in Australia has described a rare finding discovered during a prostate cancer restaging PET/CT scan -- a pulmonary tumor embolism, according to a case published on 19 September in Radiology Case Reports.
The case underscores the importance of high-quality prostate-specific membrane antigen (PSMA) radiotracers for detecting incidental findings, suggested lead author Jared Tan, of the University of Melbourne in Australia, and colleagues.
"With increased diagnostic power comes the responsibility to detect rare, previously disregarded lesions," the group wrote.
In this case, a 75-year-old woman presented with recent dyspnea and left-sided chest pain. Her history included a right nephrectomy for clear renal cell carcinoma (RCC) with renal vein involvement four years earlier. She had been treated with a tyrosine kinase inhibitor and was in remission.
Given her new symptoms, the clinicians opted to restage with hybrid F-18 DCFPyL (Pylarify) PSMA-PET and contrast-enhanced CT. The imaging demonstrated abnormal PSMA tracer uptake in the superior lingula segment of the left upper lobe of the lung. This was confirmed on high-resolution fused PET/CT images to be an eccentric filling defect in the lingula segmental pulmonary artery.
"Given the PSMA expression, this was interpreted as a new metastatic tumor thrombus. No other site of PSMA expressing metastatic disease was evident," the group wrote.
The patient was started again on pazopanib tyrosine kinase inhibitor therapy, which led to regression of the lesion on subsequent CT imaging, with the patient's chest pain and dyspnea gradually improving, they wrote.
"To our knowledge, this is the only case report describing a [pulmonary tumor embolism] in a patient with RCC detected by PSMA-PET/CT," the doctors wrote.
Despite the name, expression of PSMA is not limited to prostate cancer, the authors noted. RCC subtypes (predominantly clear cell) have also been shown to overexpress PSMA. Ultimately, the development of novel PSMA-targeting agents in PET/CT has empowered imaging specialists and oncologists with profound diagnostic capability, they wrote.
"But in doing so, it opens the doors to a multitude of previously unconsidered diagnoses," the authors concluded.
The full article is available here.
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
