Hedlund Alec,  Stern Sara,  Bohnsack John,  Hedlund Gary

Final Pr. ID: Poster #: EDU-075

To familiarize the pediatric radiologist with the important role that the perforin gene plays in lymphocyte cytotoxicity, to discuss the diversity in clinical presentation, and review the scope of neuroimaging abnormalities that may arise in the setting of a missense perforin genetic defect. The brain MRI findings and relevant clinical information of two remotely related children with the same novel missense mutation in the perforin gene represent the basis of this educational poster.

Perforin is a glycoprotein (encoded by the PRF-1 gene) involved in several human cellular functions, including, immune response and stored mainly in CD8-positive T-cells as well as natural killer (NK) cells. Normally, T-cells and NK cells are responsible for attacking dead cells. In the clinical setting of perforin deficiency, T-cells and NK cells attack the healthy immune system. This arises from a missense mutation of the PRF-1 gene. Links between perforin deficiency and the autoimmune clinical syndrome of hemophagocytic lymphohistiocytosis (HLH), have been reported.

MR imaging abnormalities in patients with perforin gene mutations, are diverse and complex as the defect may occur in the setting of familial hemophagocytic lymphohistiocytosis, primary necrotizing lymphocytic CNS vasculitis or associated with CNS infections such as the Epstein Barr virus.

To date, MRI abnormalities that have been reported include mimics of septic cerebral emboli, confluent white matter abnormalities involving the cerebral hemispheres and cerebellum invoking the consideration of diffuse demyelinating disease, and multifocal infratentorial and supratentorial intraaxial lesions with “necrotic-like” character and marginal enhancement. Multifocal sites of perivascular space pathological enhancement has also been reported. Common to many of these reports is cerebellar involvement.

The imaging differential diagnosis includes atypical infection, histocytic disorders of the CNS, lymphomatous granulomatosis, neurosarcoidosis, and primary CNS lymphoma. Read More

Authors:  Hedlund Alec , Stern Sara , Bohnsack John , Hedlund Gary

Keywords:  Perforin defect, Chronic encephalitis, Necrotizing vasculitis

Gagnon Marie-helene,  Richer Edward,  Alazraki Adina

Final Pr. ID: Poster #: CR-030

A 16 year old previously healthymale patient who initially presented with daily recurrent fevers and chills lasting 5-10 minutes. His parents brought him to a tertiary care hospital after developing vomiting and weight loss in the setting of progressively worsening fevers. Initial work up was remarkable for elevated CRP and a negative infectious workup. An MR enterography ordered to evaluate for a cause of weight loss demonstrated incidental lung base lesions. Follow up CTA revealed a lesion within the right ventricle and multiple lung nodules, concerning for endocarditis and septic emboli. He underwent two surgical resections over two months for the ventricular mass. Pathology revealed findings consistent with necrotizing endocarditis. During his hospital course, he was found to have a left cephalic venous thrombosis and was placed on Xarelto, later developing a right subclavian vein thrombus while on anticoagulation. He was readmitted 1 month later after presenting for right chest and right upper quadrant pain. Initial chest X-ray revealed right lower lobe mass and follow up CTA revealed two large right pulmonary artery pseudo-aneurysms. He underwent cardiac catheterization for pre-operative coiling of the pseudo-aneurysms and subsequent right lower lobectomy. Pathology revealed necrotizing arteritis and pulmonary artery pseudo-aneurysms. Based on clinical presentation and further work up, he was diagnosed with Hughes Stovin Syndrome and started on Cytoxan and Apixaban. While not yet considered in remission, his symptoms have improved since initiating treatment.

Hughes Stovin Syndrome (HSS) is a rare disorder characterized by thrombophlebitis as well as multiple pulmonary and/or bronchial aneurysms. There is a male predilection, usually presenting between 12-48 years. There have been less than 40 cases published in the English literature. HSS is thought to be a variant of Bechet’s but does not present with oral or genital ulcers. The lack oral and genital ulcers in this patient excluded a diagnosis of Bechet’s. The underlying cause of HSS is unclear but is believed to be due to angiodysplasia or infection. Since there is no formally described diagnostic criteria, the clinical presentation of thrombophlebitis with pulmonary artery aneurysms characterize the disease.

We present this case to illustrate the clinical presentation of a rare and possibly under recognized syndrome. Read More

Authors:  Gagnon Marie-helene , Richer Edward , Alazraki Adina

Keywords:  Vasculitis, Aneurysm, Thrombophlebitis