CLOVES syndrome and cervical arteriovenous fistula: a unique association managed by combined microsurgical and endovascular therapy

Epidural lipomatosis with foci of hemorrhage and acute compression of the spinal cord in a child with CLOVES syndrome: illustrative case

BACKGROUND

Congenital lipomatous overgrowth, vascular malformations, epidermal nevi, spinal/skeletal anomalies, and/or scoliosis (CLOVES) syndrome is the most recently described combined vascular anomaly characterized by congenital excessive growth of adipose tissue, vascular malformations, epidermal nevi, and skeletal deformities. This condition exhibits a significant variability in clinical manifestations and a tendency for rapid progression and affects extensive anatomical regions. Information regarding the association of epidural lipomatosis with low-flow venous lymphatic malformations is rare, with few reports in the literature.

OBSERVATIONS

The authors present a case of a 6-year-old girl who was admitted to the emergency department complaining of rapidly progressing weakness in her lower extremities and partial loss of sensation in the inguinal area. Radiologically, an extradural mass was identified at the T2-6 level, causing acute spinal cord compression. Urgent decompression and partial resection of the mass were performed. Despite satisfactory intraoperative hemo- and lymphostasis, postoperative lymphorrhea/seroma leakage was encountered as a delayed complication and was managed conservatively.

LESSONS

CLOVES syndrome is characterized by the combination of various clinical symptoms, not all of which are included in the abbreviation, as well as a progressively deteriorating course, the emergence of new symptoms, and complications throughout the patient's life. This necessitates ongoing monitoring of such patients.

When, where and which PIK3CA mutations are pathogenic in congenital disorders

PIK3CA encodes the class I PI3Kα isoform and is frequently mutated in cancer. Activating mutations in PIK3CA also cause a range of congenital disorders featuring asymmetric tissue overgrowth, known as the PIK3CA-related overgrowth spectrum (PROS), with frequent vascular involvement. In PROS, PIK3CA mutations arise postzygotically, during embryonic development, leading to a mosaic body pattern distribution resulting in a variety of phenotypic features. A clear skewed pattern of overgrowth favoring some mesoderm-derived and ectoderm-derived tissues is observed but not understood. Here, we summarize our current knowledge of the determinants of PIK3CA-related pathogenesis in PROS, including intrinsic factors such as cell lineage susceptibility and PIK3CA variant bias, and extrinsic factors, which refers to environmental modifiers. We also include a section on PIK3CA-related vascular malformations given that the vasculature is frequently affected in PROS. Increasing our biological understanding of PIK3CA mutations in PROS will contribute toward unraveling the onset and progression of these conditions and ultimately impact on their treatment. Given that PIK3CA mutations are similar in PROS and cancer, deeper insights into one will also inform about the other.