Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography revealed the course of granulocyte-colony stimulating factor-associated aortitis: A case report.

A 72-year-old man with diffuse large B-cell lymphoma underwent fluorine-18 fluorodeoxyglucose (FDG) PET/CT, revealing lymphoma lesions and no evidence of aortitis. The patient received chemotherapy and was treated with granulocyte colony-stimulating factor (G-CSF) for neutropenia. During chemotherapy, the patient underwent PET/CT again, revealing FDG accumulation and wall thickening at the aortic arch, which suggested aortitis. The patient was only experiencing fatigue. G-CSF-associated aortitis was suspected, and the original G-CSF was switched to another G-CSF while continuing chemotherapy. Three months later, the third round of PET/CT showed that FDG accumulation and wall thickening of the aortic arch vanished. PET/CT may be useful for not only the diagnosis but follow-up of G-CSF-associated aortitis. Radiologists should recognize incidental aortitis on PET/CT in patients receiving G-CSF administration.

"Bloomy rind sign" in varicella-zoster virus brainstem meningoencephalitis.

The bloomy rind sign, characterized by band-like abnormalities along the surface of the brainstem on magnetic resonance imaging without contrast enhancement, has been considered a specific imaging marker for leptomeningeal metastasis from lung adenocarcinoma. In this study, we describe the case of an 85-year-old male with a 3-week history of headache, fever, and progressive cognitive impairment. The patient was diagnosed with varicella-zoster virus brainstem meningoencephalitis and magnetic resonance imaging revealed hyperintensities along the brainstem surface on fluid-attenuated inversion recovery and diffusion-weighted imaging that mimicked a bloomy rind sign. However, the patient showed no signs of lung cancer or meningeal carcinomatosis. This case suggests that the bloomy rind sign is not exclusive to leptomeningeal metastasis but can also be observed in other conditions, such as central nervous system infections.

Pembrolizumab-Associated Pneumonitis Resembling Lymphangitic Carcinomatosis in a Melanoma Patient.

ABSTRACT: In recent years, many articles have described the adverse events associated with immune checkpoint inhibitors. We report the case of a 63-year-old woman with bilateral lung shadows after 1-year pembrolizumab immunotherapy following surgery for the right-foot melanoma because of positive sentinel lymph nodes. Follow-up 18 F-FDG PET/CT demonstrated bilateral diffuse mass-like peribronchovascular opacities with marked FDG uptake. Clinically, melanoma metastases with lymphangitic spread were suspected, and bronchoscopy was performed, although no evidence of malignancy was found. The lung shadow was mostly resolved after steroid treatment. Pembrolizumab-induced pneumonitis can be a mimicker of melanoma metastasis with lymphangitic spread.

Dynamic contrast-enhanced MRI and sequential CT findings of metaplastic breast carcinoma in neurofibromatosis type 1: A case report.

Metaplastic breast carcinoma in neurofibromatosis type 1 is extremely rare. There are few reports about dynamic contrast-enhanced MRI findings and sequential CT findings of metaplastic breast carcinoma in neurofibromatosis type 1. Herein, we report imaging findings, including dynamic contrast-enhanced MRI and sequential CT, of metaplastic breast carcinoma in an 82-year-old woman with neurofibromatosis type 1. Short tau inversion recovery image revealed an oval mass with a circumscribed margin that exhibited moderate intensity with partially hyperintense area inside, and T1-weighted imaging revealed a spotty hyperintense area. The solid component of the mass showed heterogeneous enhancement and the time-intensity curve had a fast/washout pattern with restricted diffusion. In addition, multiple neurofibromas were observed. Sequential CT revealed that the diameter of the mass doubled in 3 months without apparent lymph node metastasis. Because detection of metaplastic breast carcinoma in neurofibromatosis type 1 tends to be delayed due to multiple neurofibromas, characteristic MRI findings suggestive of metaplastic breast carcinoma and sequential CT findings are important for early treatment of metaplastic breast carcinoma in patients with neurofibromatosis type 1.

Cerebral proliferative angiopathy depicted by four-dimensional computed tomographic angiography: A case report.

Cerebral proliferative angiopathy is a rare cerebrovascular disorder characterized by diffuse abnormal vessels with intermingled brain parenchyma fed by many arteries and draining into many veins without high-flow arteriovenous shunts, which is usually confirmed by conventional digital subtraction angiography. However, dilution of the contrast medium due to the markedly increased blood flow and volume in cerebral proliferative angiopathy leads to low-contrast angiography. We report a 53-year-old man with cerebral proliferative angiopathy who underwent CT, MR imaging, MR angiography, digital subtraction angiography and 4D-CTA. The 4D-CTA exhibited abnormal vessels without early venous filling between the atrophic brain parenchyma in higher contrast than the angiography due to high spatial and time resolution, whereas the left external carotid angiography visualized the characteristic transdural supply more clearly than the 4D-CTA due to high vascular selectivity. Therefore, novel 4D-CTA and conventional angiography plays a complementary role in the accurate diagnosis of cerebral proliferative angiopathy. Taking invasiveness into account, 4D-CTA may be advantageous for the diagnosis of cerebral proliferative angiopathy based on the characteristic imaging findings.