Clinical Phenotype and Bone Biopsy Characteristics in a Child with Proteus Syndrome

Proteus syndrome is a rare genetic disorder, which is characterized by progressive, segmental, or patchy overgrowth of diverse tissues of all germ layers, including the skeleton. Here, we present a 9-year-old girl with a somatic-activating mutation (c.49G > A; p.Glu17Lys) in AKT1 gene in a mosaic status typical for Proteus syndrome. She presented with hemihypertrophy of the right lower limb and a "moccasin" lesion among others. A transiliac bone biopsy was analyzed for bone histology/histomorphometry as well as bone mineralization density distribution (BMDD) and osteocyte lacunae sections (OLS) characteristics based on quantitative backscattered electron imaging. Bone histomorphometry revealed highly increased mineralizing surface (Z-score + 2.3) and mineral apposition rate (Z-score + 19.3), no osteoclasts (Z-score - 2.1), and an increased amount of primary bone in the external cortex. BMDD abnormalities included a decreased mode calcium concentration in cancellous bone (Z-score - 1.7) and an increased percentage of highly mineralized cortical bone area (Z-score + 2.4) compared to reference. OLS characteristics showed several differences compared to reference data; among them, there were the highly increased OLS-porosity, OLS-area, and OLS-perimeter on the external cortex (Z-scores + 6.8, + 4.4 and 5.4, respectively). Our findings suggest that increased bone formation reduced matrix mineralization in cancellous bone while the enhanced amount of primary bone in the external cortex increased the portion of highly mineralized cortical bone and caused OLS-characteristics abnormalities. Our results indicate further that remodeling of primary bone might be disturbed or delayed in agreement with the decreased number of osteoclasts observed in this child with Proteus syndrome.

[Proteus syndrome in the practice of an otorhinolaryngologist: a clinical case]

Described a rare clinical observation of a patient aged 18 years with chronic left-sided otitis media against Proteus syndrome. By this age, the patient underwent a large number of operations regarding the removal of lymphangiomas, hemlimfangiomas, angiokeratitis of the body, as well as several sanitizing surgery on the left ear. A review of domestic and foreign literature showed that this case can be considered unique.

Proteus syndrome: A case report and review of the literature

Proteus syndrome is a rare complex syndrome involving clinical presentation with atypical skeletal growth. Only a limited number of cases with this syndrome have been reported in the literature to date. We herein report the case of a Chinese male patient with Proteus syndrome and review the clinical and molecular characteristics of this disease. The patient was a 34-year-old man with clinical manifestations suggestive of the Proteus syndrome, including mosaic distribution of the lesions, sporadic occurrence, progressive course, disproportionate overgrowth of the legs, epidermal nevi, lipomas, venous malformations and characteristic facial phenotype. Genetic mosaicism, such as mutations involving the phosphoinositide 3 kinase-AKT pathway in the affected tissues, may be important causes of Proteus syndrome. In the present case, samples from the affected tissues were collected from the patient and were further analyzed using whole-exome sequencing. However, no mutation of the genes reportedly associated with Proteus syndrome was identified in the affected tissues. Proteus syndrome is a complex mosaic disorder with a number of variable characteristics. Although activating AKT1 mutations have been found to be associated with this disorder, the molecular etiology remains to be fully elucidated and diagnostic criteria must be established in the clinical setting.

Phosphoinositide 3-kinase: a new kid on the block in vascular anomalies

Vascular anomalies are broadly divided into vascular tumours and malformations. These lesions are composed of abnormal vascular elements of various types, and mainly affect infants, children, and young adults. Vascular anomalies may be painful, may be complicated by bleeding, infection, or organ dysfunction, and can have secondary effects on other tissues. Current treatment strategies include surgical excision, pulsed laser, and sclerotherapy, which are invasive, with risks of recurrence. There are growing pharmacological options for these vascular anomalies, but, to date, no specific targeted therapies have been developed. Phosphoinositide 3-kinases (PI3Ks) constitute a family of lipid kinases that are involved in signal transduction and vesicular traffic, and that modulate important cellular processes such as proliferation, growth, and migration. Recent findings have indicated that the PI3K signalling pathway is important in the pathogenesis of vascular anomalies. This provides an opportunity to use PI3K inhibitors, which are in clinical trials for cancer treatment, for such lesions. Here, we provide an update on the classification of vascular anomalies, with their major features, and discuss the role of the PI3K signalling pathway in the pathogenesis of vascular anomalies, and their clinical implications and therapeutic opportunities. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Evidence for SH2 domain-containing 5'-inositol phosphatase-2 (SHIP2) contributing to a lymphatic dysfunction

The lymphatic vasculature plays a critical role in a number of disease conditions of increasing prevalence, such as autoimmune disorders, obesity, blood vascular diseases, and cancer metastases. Yet, unlike the blood vasculature, the tools available to interrogate the molecular basis of lymphatic dysfunction/disease have been lacking. More recently, investigators have reported that dysregulation of the PI3K pathway is involved in syndromic human diseases that involve abnormal lymphatic vasculatures, but there have been few compelling results that show the direct association of this molecular pathway with lymphatic dysfunction in humans. Using near-infrared fluorescence lymphatic imaging (NIRFLI) to phenotype and next generation sequencing (NGS) for unbiased genetic discovery in a family with non-syndromic lymphatic disease, we discovered a rare, novel mutation in INPPL1 that encodes the protein SHIP2, which is a negative regulator of the PI3K pathway, to be associated with lymphatic dysfunction in the family. In vitro interrogation shows that SHIP2 is directly associated with impairment of normal lymphatic endothelial cell (LEC) behavior and that SHIP2 associates with receptors that are associated in lymphedema, implicating its direct involvement in the lymphatic vasculature.

Pressing the right buttons: signaling in lymphangiogenesis

Lymphatic vasculature is increasingly recognized as an important factor both in the regulation of normal tissue homeostasis and immune response and in many diseases, such as inflammation, cancer, obesity, and hypertension. In the last few years, in addition to the central role of vascular endothelial growth factor (VEGF)-C/VEGF receptor-3 signaling in lymphangiogenesis, significant new insights were obtained about Notch, transforming growth factor β/bone morphogenetic protein, Ras, mitogen-activated protein kinase, phosphatidylinositol 3 kinase, and Ca2+/calcineurin signaling pathways in the control of growth and remodeling of lymphatic vessels. An emerging picture of lymphangiogenic signaling is complex and in many ways distinct from the regulation of angiogenesis. This complexity provides new challenges, but also new opportunities for selective therapeutic targeting of lymphatic vasculature.

Lymphatic vessel abnormalities arising from disorders of Ras signal transduction

A number of genetic diseases in man have been described in which abnormalities in the development and function of the lymphatic vascular (LV) system are prominent features. The genes that are mutated in these diseases are varied and include genes that encode lymphatic endothelial cell (LEC) growth factor receptors and their ligands and transcription factors that control LEC fate and function. In addition, an increasing number of genes have been identified that encode components of the Ras signal transduction pathway that conveys signals from cell surface receptors to regulate cell growth, proliferation, and differentiation. Gene targeting studies performed in mice have confirmed that the LV system is particularly susceptible to perturbations in the Ras pathway.

Connective tissue nevi in children: institutional experience and review

BACKGROUND

Connective tissue nevi (CTN) are circumscribed hamartomas of the skin in which there is an abnormal mixture of normal components of the dermis that may be sporadic or associated with syndromes such as Buschke-Ollendorff, tuberous sclerosis, and Proteus.

OBJECTIVE

We sought to specify the clinical and histologic features of CTN in childhood and to propose a diagnostic approach and updated classification.

METHODS

This was a retrospective study in a tertiary pediatric outpatient population, accessing clinical and histopathological records.

RESULTS

We classified 114 cases of CTN from 1980 to 2008.

LIMITATIONS

The majority of cases were confirmed by histopathological examination. Therefore, our series excludes many CTN that were not biopsied. In addition, follow-up was variable.

CONCLUSION

Our series demonstrates the usefulness of a modified classification for CTN. Biopsy should be done when clinical diagnosis is uncertain, or in multiple lesions. When biopsy is performed it should include normal-appearing skin for comparison and, in Buschke-Ollendorff syndrome, limited anterior-posterior x-rays of the hands, wrists, feet, ankles, knees, and pelvis instead of a full skeletal survey.

The group of epidermal nevus syndromes Part I. Well defined phenotypes

The epidermal nevus syndromes represent a group of distinct disorders that can be distinguished by the type of associated epidermal nevus and by the criterion of presence or absence of heritability. Well defined syndromes characterized by organoid epidermal nevi include Schimmelpenning syndrome, phacomatosis pigmentokeratotica, nevus comedonicus syndrome, angora hair nevus syndrome, and Becker nevus syndrome. The molecular basis of these disorders has so far not been identified. By contrast, the group of syndromes characterized by keratinocytic nevi comprises three phenotypes with a known molecular etiology in the form of CHILD (congenital hemidysplasia with ichthyosiform nevus and limb defects) syndrome, type 2 segmental Cowden disease, and fibroblast growth factor receptor 3 epidermal nevus syndrome (García-Hafner-Happle syndrome), whereas Proteus syndrome is still of unknown origin. From this overview, it is clear that a specific type of these disorders cannot be classified by the name "epidermal nevus syndrome" nor by the terms "organoid nevus syndrome" or "keratinocytic nevus syndrome."

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to distinguish nine different epidermal nevus syndromes by their characteristic features, understand the practical significance of avoiding terms like "epidermal nevus syndrome" or "keratinocytic nevus syndrome" to define any specific entity within this group of disorders, and differentiate between nonhereditary traits and those bearing a genetic risk because of either Mendelian or non-Mendelian inheritance.

Unilateral ovarian dermoid cyst accompanied by an ipsilateral paratubal cyst in a girl with Proteus Syndrome discovered by laparoscopic surgery

BACKGROUND

Proteus syndrome is a rare hamartomatous disorder characterized by the overgrowth of multiple tissues in a mosaic pattern. Tumors of genitourinary tract in Proteus syndrome are uncommon.

CASE

We here report a 5-year-old girl with Proteus syndrome who developed a cystic mass in the pelvic cavity. The cyst was discovered by ultrasonographic examination and finally proved to be a unilateral ovarian dermoid cyst accompanied by an ipsilateral paratubal cyst by laparoscopic surgery.

SUMMARY AND CONCLUSION

Proteus syndrome accompanied by an ovarian cyst is rare in girls. The possibilities of underlying ovarian cyst required for surgical intervention should be considered in Proteus syndrome.