PIK3CA-related overgrowth spectrum (PROS): new insight in known diseases

Rare Case of Abdominal Aortic and Multiple Visceral Aneurysms in a Pediatric Patient With PIK3CA Mutation and Vasculitis

Abdominal aortic aneurysms (AAA) are most commonly observed in elderly male patients and are particularly rare in children. Among the pediatric population, they are usually diagnosed in the context of connective tissue disorders, genetic mutations, or vasculitis. The same is true of visceral arteries aneurysms. This case report describes the staged management of an 11-year-old patient presenting PIK3CA mutation and a 5.8 cm infrarenal AAA associated with bilateral common iliac arteries and multiple visceral aneurysms, the largest observed in the superior mesenteric artery (SMA = 3.2 cm). After careful evaluation, decision was made to first approach the most life-threatening lesion (the infrarenal AAA due to the large diameter) and the remaining aneurysms in secondary procedures, with special attention to the SMA aneurysm. The patient underwent a staged repair, with the first phase consisting of an aortobi-iliac graft with the distal anastomosis made at the left common iliac artery and right external iliac artery. The right hypogastric artery was ligated. The second procedure consisted of SMA aneurysm repair with a plication technique, as 7 branches were visualized coming off the aneurysm sac. Postoperative pathology analysis of the aortic and SMA aneurysms sac revealed vasculitis with a mixed inflammatory pattern and a COL3A1 gene heterozygote variant. He is currently in his 18th month after the last surgical intervention, receiving immunomodulatory therapy, with a planned follow-up by the interdisciplinary team to monitor the medications' side effects and the diameter of the remaining visceral aneurysms.

PIK3CA-related overgrowth spectrum (PROS) presenting as isolated macrodactyly

PIK3CA-related overgrowth spectrum (PROS) is a heterogeneous group of diseases, with varied clinical presentations ranging from isolated segmental overgrowths to megalencephaly and vascular malformations, all resulting from post-zygotic activating mutations in PIK3CA. Isolated macrodactyly of upper limb is extremely rare, accounting only for 0.9%-1% of all congenital anomalies of the upper limb. This report describes a case of congenital, isolated, nonprogressive macrodactyly of the right index finger and thumb, in an adult patient that was treated with debulking surgery. The microscopic features were compatible with lipomatosis of nerve. Due to the prompt and pertinent molecular testing, which identified a somatic PIK3CA variant, c.3140A > G, p.H1047R., the case was classified as a PROS. The availability of mTOR inhibitors offers additional treatment possibilities in cases with progressive disease. This case report highlights the importance of molecular testing to identify PROS, to further the knowledge of this continually expanding entity.

Congenital Brain Malformations: An Integrated Diagnostic Approach

Congenital brain malformations are abnormalities present at birth that can result from developmental disruptions at various embryonic or fetal stages. The clinical presentation is nonspecific and can include developmental delay, hypotonia, and/or epilepsy. An informed combination of imaging and genetic testing enables early and accurate diagnosis and management planning. In this article, we provide a streamlined approach to radiologic phenotyping and genetic evaluation of brain malformations. We will review the clinical workflow for brain imaging and genetic testing with up-to-date ontologies and literature references. The organization of this article introduces a streamlined approach for imaging-based etiologic classification into malformative, destructive, and migrational abnormalities. Specific radiologic ontologies are then discussed in detail, with correlation of key neuroimaging features to embryology and molecular pathogenesis.