Say What? Bannayan-Riley-Ruvalcaba Syndrome Presenting with Gastrointestinal Bleeding Due to Hamartoma-Induced Intussusception

A New Frameshift Mutation of PTEN Gene Associated with Cowden Syndrome-Case Report and Brief Review of the Literature

Cowden syndrome (CS) is a rare disease that was first described in 1963 and later included in the large group of genodermatoses. It is the most common syndrome among the PTEN-associated hamartomatous tumor syndromes (PHTS). CS has an autosomal dominant inheritance pattern, with increased penetrance and variable expressivity, making early diagnosis difficult. Mutations in the PTEN gene (phosphatase and TENsin homolog) are involved in its pathogenesis, involving many organs and systems originating in the three embryonic layers (ectodermum, endodermum, and mesodermum). The consequence is the development of hamartomatous lesions in various organs (brain, intestines, thyroid, oropharyngeal cavity, colon, rectum, etc.). Multiple intestinal polyps are common in patients with CS, being identified in over 95% of patients undergoing colonoscopy. The authors describe the case of a patient who presented the first signs of the disease at 3 ½ years (tonsil polyp) but was diagnosed only at the age of 20 following a colonoscopy that revealed hundreds of intestinal polyps, suggesting further molecular testing. A heterozygous frameshift mutation was identified in the PTEN gene, classified as a potentially pathogenic variant (c.762del.p(Val255*)). The authors present this case to highlight the path taken by the patient from the first symptoms to the diagnosis and to emphasize the clinical aspects of this mutational variant that have still not been identified in other patients with this syndrome.

Gastrointestinal manifestations in PTEN hamartoma tumor syndrome

The PTEN hamartoma tumor syndrome (PHTS) is a heterogeneous set of multisystem disorders caused by germline pathogenic variants in the PTEN tumor suppressor gene. Manifestations include developmental anomalies and proliferative lesions. Evidence of involvement of the GI tract has accrued over time, leading to the incorporation of GI manifestations (multiple hamartomas, glycogenic acanthosis and colorectal cancer) into the diagnostic criteria. Polyps of the upper and lower GI tract are found in most adult patients and in a significant fraction of children. Polyps tend to be of mixed histology, with a predominance of hamartomas and ganglioneuromas. PHTS patients are also at increased risk of colorectal cancer, and surveillance by colonoscopy is advised starting at the age of 35-40 years. A number of additional manifestations, including eosinophilic gastrointestinal disorders, have been observed in few or single cases, and their association with PHTS has yet to be determined.

Vascular malformations syndromes: an update

PURPOSE OF REVIEW

To provide an update of vascular malformation syndromes by reviewing the most recent articles on the topic and following the new International Society for the Study of Vascular Anomalies (ISSVA) 2018 classification.

RECENT FINDINGS

This review discusses the main features and diagnostic approaches of the vascular malformation syndromes, the new genetic findings and the new therapeutic strategies developed in recent months.

SUMMARY

Some vascular malformations can be associated with other anomalies, such as tissue overgrowth. PIK3CA-related overgrowth spectrum (PROS) is a group of rare genetic disorders with asymmetric overgrowth caused by somatic mosaic mutations in PI3K-AKT-mTOR pathway that encompass a heterogeneous group of rare disorder that are associated with the appearance of overgrowth. CLOVES syndrome and Klippel-Trénaunay syndrome are PROS disease. Proteus syndrome is an overgrowth syndrome caused by a somatic activating mutation in AKT1. CLOVES, Klippel-Trénaunay and Proteus syndromes are associated with high risk of thrombosis and pulmonary embolism. Hereditary hemorrhagic telangiectasia is an autosomic dominant disorder characterized by the presence of arteriovenous malformations. New therapeutic strategies with bevacizumab and thalidomide have been employed with promising results.

PTEN Hamartoma tumor syndrome in childhood: A review of the clinical literature

PTEN hamartoma tumor syndrome (PHTS) is a highly variable autosomal dominant condition associated with intellectual disability, overgrowth, and tumor predisposition phenotypes, which often overlap. PHTS incorporates a number of historical clinical presentations including Bannayan-Riley-Ruvalcaba syndrome, Cowden syndrome, and a macrocephaly-autism/developmental delay syndrome. Many reviews in the literature focus on PHTS as an adult hamartoma and malignancy predisposition condition. Here, we review the current literature with a focus on pediatric presentations. The review starts with a summary of the main conditions encompassed within PHTS. We then discuss PHTS diagnostic criteria, and clinical features. We briefly address rarer PTEN associations, and the possible role of mTOR inhibitors in treatment. We acknowledge the limited understanding of the natural history of childhood-onset PHTS as a cancer predisposition syndrome and present a summary of important management considerations.