Proteus syndrome: clinical evidence for somatic mosaicism and selective review

Genome-wide detection of somatic mosaicism at short tandem repeats

MOTIVATION

Somatic mosaicism has been implicated in several developmental disorders, cancers, and other diseases. Short tandem repeats (STRs) consist of repeated sequences of 1-6 bp and comprise >1 million loci in the human genome. Somatic mosaicism at STRs is known to play a key role in the pathogenicity of loci implicated in repeat expansion disorders and is highly prevalent in cancers exhibiting microsatellite instability. While a variety of tools have been developed to genotype germline variation at STRs, a method for systematically identifying mosaic STRs is lacking.

RESULTS

We introduce prancSTR, a novel method for detecting mosaic STRs from individual high-throughput sequencing datasets. prancSTR is designed to detect loci characterized by a single high-frequency mosaic allele, but can also detect loci with multiple mosaic alleles. Unlike many existing mosaicism detection methods for other variant types, prancSTR does not require a matched control sample as input. We show that prancSTR accurately identifies mosaic STRs in simulated data, demonstrate its feasibility by identifying candidate mosaic STRs in Illumina whole genome sequencing data derived from lymphoblastoid cell lines for individuals sequenced by the 1000 Genomes Project, and evaluate the use of prancSTR on Element and PacBio data. In addition to prancSTR, we present simTR, a novel simulation framework which simulates raw sequencing reads with realistic error profiles at STRs.

AVAILABILITY AND IMPLEMENTATION

prancSTR and simTR are freely available at https://github.com/gymrek-lab/trtools. Detailed documentation is available at https://trtools.readthedocs.io/.

Genome-wide detection of somatic mosaicism at short tandem repeats

Motivation

Somatic mosaicism, in which a mutation occurs post-zygotically, has been implicated in several developmental disorders, cancers, and other diseases. Short tandem repeats (STRs) consist of repeated sequences of 1-6bp and comprise more than 1 million loci in the human genome. Somatic mosaicism at STRs is known to play a key role in the pathogenicity of loci implicated in repeat expansion disorders and is highly prevalent in cancers exhibiting microsatellite instability. While a variety of tools have been developed to genotype germline variation at STRs, a method for systematically identifying mosaic STRs (mSTRs) is lacking.

Results

We introduce prancSTR, a novel method for detecting mSTRs from individual high-throughput sequencing datasets. Unlike many existing mosaicism detection methods for other variant types, prancSTR does not require a matched control sample as input. We show that prancSTR accurately identifies mSTRs in simulated data and demonstrate its feasibility by identifying candidate mSTRs in whole genome sequencing (WGS) data derived from lymphoblastoid cell lines for individuals sequenced by the 1000 Genomes Project. Our analysis identified an average of 76 and 577 non-homopolymer and homopolymer mSTRs respectively per cell line as well as multiple cell lines with outlier mSTR counts more than 6 times the population average, suggesting a subset of cell lines have particularly high STR instability rates.

Availability

prancSTR is freely available at https://github.com/gymrek-lab/trtools.

Documentation

Detailed documentation is available at https://trtools.readthedocs.io/.

A rare gynecologic presentation of proteus syndrome: A case report

Proteus syndrome is a genetic condition with an estimated incidence of less than one in a million. This condition is sporadic and presents as progressive, mosaic overgrowth of different tissues. Clinical manifestations are diverse, with the reported involvement of lungs, skin, blood cells, the nervous system and bones. Gynecologic manifestations have rarely been reported in the literature. This case is the first to be reported in the literature of a woman with Proteus syndrome diagnosed in her prepubertal years and presenting at 34 years old with a cervical mass protruding from the vagina. The patient sought medical intervention only after the prolapse was advanced and symptomatic. Management of this case was surgical and consisted of vaginal hysterectomy, with vaginal suspension.

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Proteus syndrome is a rare genetic, sporadic syndrome characterized by progressive overgrowth of tissue.

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Gynecologic manifestations of Proteus syndrome have an incidence of about 1 in a million.

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Rare case of vaginal prolapse for a cervical mass for a patient with Proteus syndrome.

Phenotype and Surgical Treatment in a Case of Proteus Syndrome With Craniofacial and Oral Findings

BACKGROUND/AIM

Proteus syndrome is a sporadic disease that is particularly noticeable due to the disproportional growth of body segments. The disease is a genetic mosaic. The mutations can arise from any of the germ layers, an explanation of the very variable phenotype. The aim of this report is to communicate the diagnosis and management of an unusual case of Proteus Syndrome with special attention to oral and craniofacial findings.

CASE REPORT

A 15-year-old patient was referred for surgical treatment of pronounced skull malformations and correction of oral mucosal hyperplasia. Treatment caused significant improvement in facial appearance and oral soft tissue conditions.

CONCLUSION

Surgical measures adapted to the local findings and symptoms can often relieve severe disfigurement of the patient.

Characterization and Childhood Tumor Risk Assessment of Genetic and Epigenetic Syndromes Associated With Lateralized Overgrowth

Lateralized overgrowth (LO), or segmental overgrowth, is defined as an increase in growth of tissue (bone, muscle, connective tissue, vasculature, etc.) in any region of the body. Some overgrowth syndromes, characterized by both generalized and lateralized overgrowth, have been associated with an increased risk of tumor development. This may be due to the underlying genetic and epigenetic defects that lead to disrupted cell growth and proliferation pathways resulting in the overgrowth and tumor phenotypes. This chapter focuses on the four most common syndromes characterized by LO: Beckwith-Wiedemann spectrum (BWSp), PIK3CA-related overgrowth spectrum (PROS), Proteus syndrome (PS), and PTEN hamartoma tumor syndrome (PHTS). These syndromes demonstrate variable risks for tumor development in patients affected by LO, and we provide a comprehensive literature review of all common tumors reported in patients diagnosed with an LO-related disorder. This review summarizes the current data on tumor risk among these disorders and their associated tumor screening guidelines. Furthermore, this chapter highlights the importance of an accurate diagnosis when a patient presents with LO as similar phenotypes are associated with different tumor risks, thereby altering preventative screening protocols.

Severe gynaecological involvement in Proteus Syndrome

Proteus Syndrome is a rare complex overgrowth syndrome. We report a young female patient with Proteus Syndrome due to AKT1 mutation c.49G > A (p.Glu17Lys), presenting with a severe gynaecological involvement which necessitated a complete hysterectomy and a left adnexectomy. Cases of gynecological involvements in Proteus Syndrome are rare, not well known by physicians while they can be potentially severe.

Vascular Stains: Proposal for a Clinical Classification to Improve Diagnosis and Management

Vascular stains are a common reason for consultation in pediatric dermatology clinics. Although vascular stains include all vascular malformations, the term is most often used to refer to capillary malformations, but capillary malformations include a wide range of vascular stains with different clinical features, prognoses, and associated findings. The discovery of several mutations in various capillary malformations and associated syndromes has reinforced these differences, but clinical recognition of these different types of capillary vascular stains is sometimes difficult, and the multitude of classifications and confusing nomenclature often hamper the correct diagnosis and management. From our own experience and a review of the most relevant literature on this topic, we propose categorizing patients with capillary vascular stains into seven major clinical patterns: nevus simplex, port-wine stain, reticulated capillary malformation, geographic capillary malformation, capillary malformation-arteriovenous malformation (CM-AVM), cutis marmorata telangiectatica congenita, and telangiectasia. We also discuss the differential diagnosis of vascular stains as well as other conditions that can closely resemble capillary malformations and thus may potentially be misdiagnosed.

Desafios clínicos e psicossociais no tratamento de um paciente com síndrome de Proteus

Resumo A Síndrome de Proteus é uma rara associação de malformações que podem afetar vários tecidos e órgãos. É caracterizada por macrodactilia bilateral, hipertrofia craniana, anomalias ósseas, escoliose, hamartomas de tecidos moles, nevo verrucoso pigmentar, anormalidades viscerais e outras hipertrofias. Há pouco mais de 200 casos notificados em todo o mundo. O presente artigo relata a evolução clínica de um paciente pediátrico com essa síndrome. A criança apresentou desnutrição grave associada ao extremo gigantismo de membros inferiores. Além disso, apresentou repercussões psicossociais relacionadas à exclusão social. A doença tornou-se mais grave e progrediu como síndrome consumptiva. Finalmente, os pais concordaram com a amputação dos membros inferiores hipertróficos. Um ano após as amputações, a criança estava totalmente reabilitada, protetizada dos membros amputados, com melhora nutricional, além de apresentar notória recuperação psicológica e reinserção social, o que representou melhora significativa da qualidade de vida para o paciente.

Endometrioid Paraovarian Borderline Cystic Tumor in an Infant with Proteus Syndrome

Ovarian and paraovarian neoplasms are uncommon in children, mainly originating from germ cell tumors and, least frequently, epithelial tumors. There is an association between genital tract tumors and Proteus syndrome, a rare, sporadic, and progressive entity, characterized by a postnatal overgrowth in several tissues caused by a mosaic mutation in the AKT1 gene. We describe a 20-month-old asymptomatic infant with Proteus syndrome who developed an endometrioid paraovarian borderline cystic tumor. This is the youngest patient so far reported in the literature with this rare syndrome and an adnexal tumor of borderline malignancy. A total of nine patients have been described with female tract tumors and associated Proteus syndrome, which includes bilateral ovarian cystadenomas and other benign masses. A paraovarian neoplasm is extremely rare in children and could be considered a criterion for Proteus syndrome. Standardized staging and treatment of these tumors are not well established; however, most authors conclude that these neoplasms must be treated as their ovarian counterparts.

Proteus syndrome: Report of a case with AKT1 mutation in a dental cyst

Proteus syndrome (PS) is a sporadic and rare congenital disorder characterized by a patchy or mosaic postnatal overgrowth, sometimes involving the face. The onset of overgrowth typically occurs in infancy and can commonly involve skin, connective tissue, central nervous system, eyes and viscera. The progressive overgrowth causes severe complications, such as skeletal deformities, cystic lung disease, invasive lipomas, connective tissue hyperplasia, benign and malignant tumours and deep venous thrombosis with pulmonary embolism, which can cause premature death. This disorder is caused by somatic mosaicism for a specific activating AKT1 mutation that would be lethal in a non-mosaic state. In this report, current knowledge of the aetiology, the diagnosis and the craniofacial manifestations of the disorder are reviewed. The short-term management of a 7-year-old patient with unusual oral manifestations is described. For the first time mutation of AKT1 (c.49G > A) gene was detected both in cranial exostosis and in central odontogenic fibroma of the lower jaw.

Proteus syndrome review: molecular, clinical, and pathologic features

Proteus syndrome is caused by an activating AKT1 mutation (c.49G>A, p.Glu17Lys). Many variable features are possible in this mosaic disorder, including: (i) disproportionate, asymmetric, and distorting overgrowth; (ii) bone abnormalities different from those observed in other disorders; (iii) a characteristic cerebriform connective tissue nevus made up of highly collagenized connective tissue; (iv) epidermal nevi in early life, consisting of acanthosis and hyperkeratosis; (v) vascular malformations of the capillary, venous, or lymphatic types; (vi) dysregulated adipose tissue including lipomas, lipohypoplasia, fatty overgrowth, and localized fat deposits; (vii) other unusual features, including bullous lung alterations; specific neoplasms; a facial phenotype associated with intellectual disability and/or seizures, and/or brain malformations; and (viii) deep vein thrombosis, resulting in premature death. Concluding remarks address diagnostic criteria, natural history, management, psychosocial issues, and differential diagnosis.

Proteus syndrome revealing itself after the treatment of a bilateral subdural haematoma

INTRODUCTION

Hypertrophy of the calvarium has different aetiologies, among them the rare Proteus syndrome.

CASE REPORT

We report here the case of a young girl initially treated for relapsing right then left large chronic subdural haematoma, who progressively developed craniofacial hypertrophy consistent with the diagnosis of Proteus syndrome. Calvarium hypertrophy was shaved and remodelled combining midface advancement, essentially for cosmetic purposes. During the first calvarium remodelling, important bleeding of the bone required large volume of blood replacement. Haemostasis workup revealed platelets aggregation anomalies. Bleeding issues during subsequent surgeries were controlled with tranexamic acid and desmopressin acetate.

DISCUSSION

Other manifestations of Proteus syndrome, such as a right hypertrophy of the face with hypoplasia of its middle third, a pigmented epidermal nevus and asymmetric limbs and scoliosis, appeared progressively over time. Blood and fibroblast phosphatase and tensin homolog mutation was not found.

CONCLUSION

Literature review of operated patients with Proteus syndrome did not reveal an association with platelets anomalies. A complete haemostasis workup following this unexpected haemorrhagic complication is recommended for this rare pathology.

Proteus syndrome: Clinical profile of six patients and review of literature

OBJECTIVE:

Proteus syndrome (PS) is characterized by patchy or segmental overgrowth and hyperplasia of multiple tissues and organs, along with susceptibility to development of tumors. Very few cases are reported in literature from developing countries. Due to certain overlapping features with other overgrowth syndromes, diagnosis is usually delayed. Our aim was to describe clinical profile of this rare condition in six patients.

MATERIALS AND METHODS:

Retrospective case sheet review of patients followed in a Pediatric Genetic and Metabolic clinic at a tertiary care institute of North India with a diagnosis of hemihypertrophy/overgrowth syndrome.

RESULTS:

Six cases presented with asymmetric overgrowth and peculiar features suggestive of PS were included in this study. Age at presentation was 2 months to 10 years; two were males and four were females. Hemihypertrophy was noticed in only one case at birth, and focal overgrowths in rest of other patients were seen later during childhood.

CONCLUSION:

Due to certain overlapping features with other overgrowth syndromes, diagnosis of PS is usually delayed. Pediatricians are the first persons who come across such patients and they should be aware about this rare condition.

Proteus syndrome: A rare case report

Proteus syndrome (PS) is a rare hamartomatous disorder characterized by various cutaneous and subcutaneous lesions, including vascular malformations, lipomas, hyperpigmentation, and several types of nevi. Partial gigantism with limb or digital overgrowth is pathognomonic of PS. We report a rare case of PS in a 50-year-old man who presented with inferior wall myocardial infarction and was incidentally detected to have hypertrophy of index and middle fingers of both the hands.

Neurofibromatosis type 1 and the "elephant man's" disease: the confusion persists: an ethnographic study

BACKGROUND

In 1986, two Canadian geneticists had demonstrated that Joseph Merrick, better known as the Elephant Man, suffered from the Proteus syndrome and not from neurofibromatosis type 1 (NF1), as was alleged by dermatologist Parkes in 1909. Despite this and although the two diseases differ at several levels: prevalence, diagnostic criteria, clinical manifestations and transmission, the confusion between NF1 and the "elephant man's" disease continues in medical and social representations by current linguistic usage, and in some media reports. With this article, we want to 1) document the persistence and extent of this fallacy, 2) identify certain critical factors that contribute to its persistence, and 3) evaluate its impact on the health and well being of patients with NF1 and their family members.

METHODOLOGY

Participant observation in the course of an ethnographic study on intergenerational dialogue between individuals with neurofibromatosis and their parents - Analysis of the scientific literature and of pinpoint articles in the print and online news media.

FINDINGS

Our findings show that because physicians have little knowledge about NF1, several print and online news media and a lot of physicians continue to make the confusion between NF1 and the disease the "elephant man". This misconception contributes to misinformation about the disease, feeding prejudices against affected patients, exacerbating the negative impacts of the disease on their quality of life, their cognitive development, their reproductive choices, as well as depriving them of proper care and appropriate genetic counseling.

CONCLUSION

If family physicians and pediatricians were properly informed about the disease, they could refer their patients with NF1 to NF clinics and to specialists. Thus, patients and their family members would benefit from better-tailored clinical management of their cases, perhaps even optimal management. [corrected]

Epidermal nevi

Nevi or nests of cells may be made up of a variety of cell types. The cell types that live in the epidermis include epidermal cells or keratinocytes, sebaceous glands, hair follicles, apocrine and eccrine glands, and smooth muscle cells. This article discusses epidermal or keratinocyte nevi, nevus sebaceous, nevus comedonicus, smooth muscle hamartomas, and inflammatory linear verrucous epidermal nevi. Syndromes associated with epidermal nevi are also reviewed.

Management of craniofacial hyperostosis in Proteus syndrome

Proteus syndrome is a rare congenital hamartomatous condition that is characterized by a wide range of malformations, occasionally involving the head and the face. Skin and skeletal developmental malformations are common and may be manifested in significant physical anomalies. In this report, we describe the cases of 2 patients affected by this condition. For one patient, a recurrence occurred 4 years after the elimination of cranial hyperostosis. In the second patient, although we observed macrosomia and peculiar countenance in the context of craniofacial hyperostosis, the patient did not visit a clinic for approximately 50 years before seeking treatment. The management of the craniofacial involvement is described, and a literature overview is presented.

Proteus syndrome

Proteus syndrome is a rare sporadic, hamartoneoplastic disorder of vascular, skeletal, and soft tissues that causes asymmetry of the skull, body, arms, and the legs. The name "Proteus" of the Greek god who had the ability to change his shape was coined to define the variety of deformities including partial gigantism of the hands or feet, asymmetry of the arms and legs, hypertrophy of long bones, plantar hyperplasia, haemangiomas, lipomas, varicosities, linear verrucous epidermal naevi, macrocephaly, and cranial hyperostoses. The basic defect seems to be the focal overgrowth of cellular elements in skin, bone, and other connective tissues. The variable features of the syndrome make differential diagnosis challenging for clinicians. The most important features are the hamartomatous disorders. The long-term prognosis is still not clear. As it is a hamartoneoplastic and incompletely delineated syndrome, the patients must be followed up because of the possible risk of neoplasms.

Proteus syndrome: high-resolution CT and CT pulmonary densitovolumetry findings

Cystic transformation of the lungs in Proteus syndrome is considered an important manifestation of this disease. We describe a case of an 11-year-old girl with a diagnosis of Proteus syndrome with lung involvement. Low-dose multidetector computed tomography (CT) revealed extensive diffuse cystic lung disease with left lung predominance, affecting mostly the lower lung zones. The cystic lesions had various sizes and variable wall thickness. Postprocessing using CT histogram densitometric volumetry software (CT densitovolumetry), using the threshold -950 Houndsfield units (HU) for quantifying emphysema, revealed that 31% of her total lung volume was composed of areas with CT attenuation values below -950 HU.

Proteus syndrome: report of a case with recurrent abdominal lipomatosis

Proteus syndrome (PS) is an extremely rare congenital hamartomatous syndrome that was first delineated by Cohen and Hayden (1). The estimated prevalence is less than 1 per 1,000,000 live births (2). It is a sporadic disorder that causes overgrowth of multiple tissues, especially bone, fat, and other connective tissues in a patchy or mosaic pattern. Subcutaneous as well as internal lipomas that may grow to an enormous size are frequently observed. Nevertheless, among the internal lipomas, abdominal lipomatosis is rare (3), with less than 15 cases reported. Herein, we report the first patient described with this distinctive syndrome associated with lipomatosis involving the epiploon.

Apnoea-hypopnoea and mandibular retrusion as uncommon findings associated with Proteus syndrome

The aetiology of Proteus syndrome (PS) is yet unclear. This disease includes partial gigantism of the hands and/or feet, nevi, hemihypertrophy due to overgrowth of long bones, subcutaneous tumours, macrocephaly, cranial hyperostosis, and pulmonary and renal abnormalities. This case report is about a 17-year-old boy with two uncommon findings associated with PS: apnoea-hypopnoea and mandibular retrusion. A multidisciplinary team was important to provide professional care for this patient. Dentists and physicians proposed an adjusted treatment plan. Maxillary disjunction was achieved with a combination of orthodontic treatment and surgical procedure. This represented the initial care for malocclusion treatment and also the preparation for orthognathic surgery. The oral maxillofacial surgeon and the otorhinolaryngologist proposed this approach in an attempt to improve pharynx airflow. The patient has been followed for almost 3 years.

A case of Proteus syndrome with lateral embryonal vein and frontal intraosseous lipoma

A patient with Proteus syndrome is reported with heretofore unreported features including a frontal intraosseous lipoma and a lateral embryonal leg vein (Servelle) associated with a venous malformation. These associated anomalies further broaden the phenotypic variability of Proteus syndrome.

A mild form of Proteus syndrome

Proteus syndrome is a multisystem disorder and diagnosis has been difficult because of the variability of the syndrome's manifestations. Dermatologists have an important role as cutaneous findings could provide clues for the early diagnosis of the disease. Herein we report a case who had cerebriform connective tissue nevus and lipoma as the sole manifestations of the disease.

The phakomatoses: dermatologic clues to neurologic anomalies

The phakomatoses of particular interest to neurologists including Sturge-Weber syndrome, neurofibromatosis type 1, neurofibromatosis type 2, Bannayan-Riley-Ruvalcaba syndrome, and Proteus syndrome are presented. The physical manifestations required for clinical diagnosis, the neurologic features, and recommendations for management are given. The molecular etiology and genetic aspects of these disorders are briefly discussed as well as future implications of on-going research.

[Intracranial hypertension in Proteus syndrome]

Proteus syndrome, described for the first time in 1979, is a sporadic congenital poly-malformation syndrome named for its highly variable manifestations. We report the case of a 36-year-old male patient with several malformations including skull hyperostosis and huge frontal sinus hypertrophy compressing the brain. He complained of increasing headache for 5 years. Cerebrospinal fluid pressure monitoring revealed severe hypertension. The patient underwent frontoparietal craniectomy, which allowed partial decompression. Postoperatively headaches decreased and the intracranial pressure normalized. Proteus syndrome is a genetic disease with a mosaic pattern. Only a hundred cases have been reported, mostly in childhood. Common manifestations include disproportionate overgrowth of the limbs and the skull, various subcutaneous tumors, vascular, renal and pulmonary malformations. Brain abnormalities are not common in this syndrome. When present, retardation or seizure disorders are typically seen. Intracranial hypertension is described for the first time in this syndrome.

Bone malformations in Proteus syndrome: an analysis of bone structural changes and their evolution during growth

The radiographic follow-up of a patient with Proteus syndrome is presented. Review of radiographs obtained at 3 years 10 months, 10 years, and 17 years 8 months indicated that the rate of growth in length of the oversized tubular bones of the hands was similar to that of the normal bones of the same hand. This observation supports the view that the primary lesion occurs in the early embryonic period, when the limb bud mesenchyme cells condense and cartilage differentiates producing oversized cartilage anlages, rather than being a defect of bone cell-mediated apposition and modelling processes of bone. Additional radiographs of the pelvis and spine were obtained at age 4 years 10 months and head CT at 8 years 10 months. This pathogenetic mechanism fits well with the hypothesis of somatic mosaicism, which is at present the most credible explanation for the aetiology of Proteus syndrome. Other skeletal malformations recognized as typical of the syndrome can be interpreted as secondary adaptations to the altered mechanical conditions induced by overgrowth of bones.

Vascular malformations. Part II: associated syndromes

Cutaneous vascular malformations are rare disorders representing errors in vascular development. These lesions occur much less commonly but are often confused with the common infantile hemangioma. It is important to properly diagnose vascular malformations because of their distinct differences in morbidity, prognosis and treatment. Vascular malformations may be associated with underlying disease or systemic anomalies. Several of these syndromes are well defined and can often be distinguished on the basis of the flow characteristics of the associated vascular malformation.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be able to better recognize underlying diseases or systemic anomalies that may be associated with vascular malformations. Participants should also better understand the various syndromes and conditions discussed and become more familiar with their management.

More than just a bump: the hamartoma syndromes

The hamartoma syndromes detailed in this review are just a few examples of the many genodermatoses now known to be associated with uncontrolled tumor proliferation secondary to mutations in tumor suppressor genes. Knowledge gained through the study of these syndromes has not only improved our understanding of patients afflicted with such conditions, but has also led to significant insight into the important role tumor suppressor genes play in preventing tumor formation and in carcinogenesis. As major strides continue to be made in the identification of causative mutations in the hamartoma syndromes, options for genetic testing will continue to expand. Identification of mutations in PTEN in the various disorders that compose the PTEN hamartoma tumor syndrome illustrates just how such genetic knowledge has altered the way we both categorize and manage certain genetic conditions. As advances continue to be made in this arena, it is quite conceivable that many of the genetic syndromes will be renamed or categorized based on genetic mutations rather than the characteristic clinical features. However, despite these advances, it will still be the astute clinician's recognition of key clinical features that allows the diagnosis of a hamartoma syndrome to be considered.

Proteus syndrome with giant myelolipoma in the pelvis

Proteus syndrome is a very rare and complex disorder with malformations and overgrowth of multiple tissues. This disorder was designated Proteus syndrome by Wiedemann et al. to denote its variable clinical expression. Our patient presented with macrodactyly, cerebriform appearance and a huge abdominal mass. A biopsy under laparotomy was performed, and histopathological examination revealed myelolipoma. Tumor resection was performed. To our knowledge, no case of Proteus syndrome presenting a myelolipoma in the retroperitoneal cavity has been reported before.

Follow-up and risk of tumors in overgrowth syndromes

A striking feature of the overgrowth syndromes (OGS) is the risk of cancer. In some OGS (Beckwith-Wiedemann, Perlman, Simpson-Golabi-Behmel syndromes and hemihypertrophy) tumors appeared mostly in the abdomen (more than 94% of tumors), are usually diagnosed before 10 years, and most of them are embryonal. Conversely, in other OGS, such as Sotos syndrome, the most frequent type is lympho-hematological tumors, about two-thirds are extra-abdominal and some of these tumors may appear after the second decade of life. Based on a previous literature review, a specific schedule protocol for tumor screening was suggested for many OGS. In this article we briefly review some aspects of the current knowledge of OGS and tumors, emphasizing the follow-up of these disorders.

Proteus syndrome: a rare cause of hemihypertrophy and macrodactyly on bone scanning

Proteus syndrome is a rare, sporadic genetic disorder characterized by overgrowth of multiple different tissues in a mosaic pattern. It is associated with connective tissue nevi, epidermal nevi, disproportionate overgrowth of multiple tissues, vascular malformations, characteristic tumors, and specific facial anomalies. Joseph Merrick, popularly known as the Elephant Man, is now believed to have suffered from Proteus syndrome. A case of Proteus syndrome and associated findings on bone scintigraphy are presented.

Proteus syndrome: an update

Proteus syndrome is a complex disorder consisting variably of disproportionate, asymmetric overgrowth of body parts; cerebriform connective tissue nevi; epidermal nevi; vascular malformations of the capillary, venous, and lymphatic types; and dysregulated adipose tissue. Serious complications may ensue, such as pulmonary embolism, cystic lung disease, and various neoplasms. Somatic mosaicism, lethal in the nonmosaic state, is the best working hypothesis. Although Proteus syndrome data are consistent with this hypothesis, it has not been proven. The etiology is unknown to date. Diagnostic criteria are emphasized because misdiagnosis of Proteus syndrome is common. Finally, evaluation and management are discussed.

Risk of tumorigenesis in overgrowth syndromes: a comprehensive review

Overgrowth syndromes (OGS) comprise a heterogeneous group of disorders in which the main characteristic is that either weight, height, or head circumference is 2-3 standard deviations (SD) above the mean for sex and age. A striking feature of OGS is the risk of neoplasms. Here, the relative frequency of specific tumors in each OGS, topographic location, and age of appearance is determined by reviewing published cases. In some OGS (Perlman, Beckwith-Wiedemann, and Simpson-Golabi-Behmel syndromes and hemihyperplasia) more than 94% of tumors appeared in the abdomen usually before 10 years of age, mainly embryonal in type. In Perlman syndrome, only Wilms tumor has been recorded, whereas in Sotos syndrome, lympho-hematologic tumors are most frequent. Based on literature review, a specific schedule protocol for tumor screening is suggested for each OGS. A schedule with different intervals and specific tests is proposed for a more rational cost/benefit program for these disorders.

Craniofacial hyperostoses in Proteus syndrome -- a case report

OBJECTIVE

Description of a patient with a rare syndrome leading to the partial overgrowth of craniofacial bones.

CASE REPORT

In a 17-year-old female patient with severe hyperostoses of the craniofacial bones asymmetric overgrowth of the right upper and left lower limbs, linear hyperpigmentation of the right arm and a history of regional lipomatosis were found. These manifestations were suggestive of Proteus syndrome. The management of the craniofacial involvement is described and a literature overview presented.

CONCLUSION

Proteus syndrome is a rare overgrowth syndrome probably related to a somatic mutation that involves craniofacial structures in about 30% of patients. Early diagnosis is required for adequate interdisciplinary treatment.

Reassessment of the Proteus syndrome literature: application of diagnostic criteria to published cases

The medical care of patients affected by rare disorders depends heavily on experiences garnered from prior cases, including those patients evaluated by the treating physician and those published in the medical literature. The utility of published cases is wholly dependent upon accurate diagnosis of those patients. In our experience, the rate of misdiagnosis in Proteus syndrome (PS) is high. Diagnostic criteria have been published, but these criteria have not been applied consistently and were published after many case reports appeared in the literature. We reviewed 205 cases of individuals reported to have PS in the literature and three of us independently applied the diagnostic criteria to these case reports. Our initial diagnostic congruence was 97.1% (199/205); the discrepancies in six cases were easily resolved. Only 97 (47.3%) of reported cases met the diagnostic criteria for PS; 80 cases (39%) clearly did not meet the criteria; and although 28 cases (13.7%) had features suggestive of PS, there were insufficient clinical data to make a diagnosis. Reported cases that met the PS criteria had a higher incidence of premature death, and other complications (scoliosis, megaspondyly, central nervous system abnormalities, tumors, otolaryngologic complications, pulmonary cystic malformations, dental and ophthalmogic complications) compared to those in the non-Proteus group. The cases that met the criteria were more often male, which has implications for hypotheses regarding the etiology and pathophysiology of PS. We also studied the attributes that led authors to conclude the reported patients had PS when we concluded they did not. We found that two of the diagnostic criteria (disproportionate overgrowth and connective tissue nevi) were often misinterpreted. In PS, the abnormal growth is asymmetric, distorting, relentless, and occurred at a faster rate compared to the rest of the body. Furthermore, PS was associated with irregular and disorganized bone, including hyperostoses, hyperproliferation of osteoid with variable calcification, calcified connective tissue, and elongation of long bones with abnormal thinning. In contrast, non-Proteus cases displayed overgrowth that was asymmetric but grew at a rate similar to the growth found in unaffected areas of the body. Also, the overgrowth in non-Proteus cases was associated with normal or enlarged bones together with ballooning of the overlying soft tissues. Taken together, these data show that (1) PS diagnostic criteria sort individuals with asymmetric overgrowth into distinct groups; (2) individuals with PS were more likely to have serious complications; (3) PS affects more males than females; and 4) the published diagnostic criteria are useful for clinical care and research. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

Anesthesia for proteus syndrome

Proteus syndrome is a complex disorder comprising malformations and overgrowth of multiple tissues. The disorder is highly variable affecting tissues in a mosaic pattern. A 2-year-old boy with Proteus syndrome, with epidermal verrucal naevus, hyperplastic lesions of connective tissue, hyperostosis, overgrowth of tubular bones, bilateral inguinal hernia, and juvenile intestinal polyposis was scheduled for vertebral magnetic resonance imaging (MRI) for further evaluation of malignancies. In addition to the pathological findings of this syndrome, potential complications such as difficult intubation, pulmonary hypertension, and pulmonary thromboembolism necessitate a careful preoperative and anesthetic preparation. MRI was performed under general anesthesia. There were no anesthetic complications. There are few previous reports on anesthesia in a patient with Proteus syndrome.

Radiologic Manifestations of Proteus Syndrome

Proteus syndrome is a sporadic disorder named for its highly variable manifestations. The disease causes tissue overgrowth in a mosaic pattern and may affect tissues derived from any germinal layer. The disease process is not usually apparent at birth but develops rapidly in childhood. Common manifestations include macrodactyly, vertebral abnormalities, asymmetric limb overgrowth and length discrepancy, hyperostosis, abnormal and asymmetric fat distribution, asymmetric muscle development, connective-tissue nevi, and vascular malformations. The features of Proteus syndrome indicate that the condition may be caused by a somatic alteration in a gene, but no specific genetic mutation has yet been identified. Therefore, the diagnosis and management of the disease depend heavily on clinical evaluation and imaging. Although the manifestations of Proteus syndrome are highly variable, accurate diagnosis is possible if standard diagnostic criteria are followed and if disease features are assessed in comparison with those found in similar syndromes.

Vascular anomalies in Proteus syndrome

Proteus syndrome (PS) is a complex hamartomatous disorder defined by local overgrowth (macrodactyly or hemihypertrophy), subcutaneous tumours and various bone, cutaneous and/or vascular anomalies (VA). VA are manifold in PS, but their prevalence is unknown so far. In order to further characterize PS, we studied the prevalence of VA in 22 PS patients presenting to our outpatient clinic and reviewed 100 PS patients previously reported between 1983 and 2001. The diagnosis of vascular abnormalities was made on clinical grounds and supported with imaging studies and/or histology in 12 and seven patients out of 22, respectively. Thirty-five VA were identified in 22/22 (100%) of our patients, and more than one type of VA were present in 10 of them. Vascular tumours, portwine stains (PWS), and venous anomalies (varicosities, prominent veins) were equally common. A total of 118 VA were previously reported in 70/100 (70%) PS patients; vascular hamartomas were more prevalent (56/118 = 47.5%), whilst PWS (21.2%) and venous anomalies (22.9%) were slightly less common than in our series, but there is the possibility of under-reporting. Unlike Klippel-Trenaunay syndrome, where VA are mostly confined to the hypertrophic limb, major arteriovenous anomalies are rare, and - similar to the other hamartomas and naevi observed in PS (pigmentary naevi, epidermal naevi, subcutaneous tumours, exostoses) - VA appear to be distributed at random sites on the body. We conclude that VA are among the most common findings in PS. Their varying type and distribution lend further support to the concept of somatic mosaicism.

Malformações vasculares

Com o conhecimento cada vez maior da angiogênese, as anomalias vasculares foram divididas em tumores e malformações vasculares. As malformações vasculares, objeto deste trabalho, são categorizadas ou pela natureza dos canais vasculares (capilares, arteriais, venosos ou linfáticos), ou pelo tipo de fluxo (alto ou baixo), ou ainda pela distribuição (localizadas ou difusas). Além disso, há as malformações complexas combinadas, nas quais se encaixa a maioria das síndromes vasculares. Os autores apresentam uma revisão do asssunto, discorrendo sobre características clínicas, diagnóstico e tratamento dessas anomalias.

[Proteus syndrome: report of two cases]

Proteus syndrome is a complex disorder, consisting of mesodermal and skeletal malformations as well as hamartomatous overgrowth. It is characterized by highly variable presentation and mosaic-pattern lesions. The two cases described herein illustrate the wide polymorphism of this syndrome. The second case also had a pubic fracture, which we have not previously seen reported in the medical literature on Proteus syndrome.

Somatic gene mutation and human disease other than cancer

While the focus of much mutation research is on germ-line mutation, somatic mutation is being found to be important in human disease. Neurofibromatosis 1 and McCune-Albright are disorders which are detected in the skin and other systems. The skin manifestations were essential for the demonstration of somatic mosaicism in neurofibromatosis 1, while analysis of blood DNA demonstrated somatic mutation in neurofibromatosis 2. Incontinentia pigmenti is also a disorder seen in skin and other tissues, but here it is the rare variant of the disorder in males, where it is usually lethal, that involves somatic mosaicism. Paroxysmal nocturnal hemoglobinuria is a disorder of the blood and cell separation of blood elements allows the demonstration of the somatic mosaicism. This review also discusses disorders in which somatic mosaicism, for mutations probably incompatible with life if the mutation had been germ-line, are likely to be involved. These include the Proteus syndrome, which involves both vascular tissues and bones, and two disorders which might be thought of as representing two subtypes of Proteus: Klippel-Trenaunay, which involves vascular tissues, and Maffuci, which involves bones. Embryonic mutations, which create mosaicism for both the soma and germ-line, are being increasingly found in a number of disorders and are discussed more briefly. Finally, reverse mutations involving the soma have been recently found in several disorders and such revertant mutations are also examined. While the review focuses on the clinical importance of somatic mutations, many of the mutations found to date are tabulated. It is too early to see if there is a different pattern of somatic mutation as compared to germ-line mutation. Although the parameters to allow careful quantitation are not yet available, it seems that the frequency of gene mutation in embryonic cells is not markedly different than that in the germ-line.

Mental deficiency, alterations in performance, and CNS abnormalities in overgrowth syndromes

Mental deficiency, alterations in performance, and central nervous system (CNS) abnormalities are discussed in the following overgrowth syndromes: Sotos syndrome, Weaver syndrome, Proteus syndrome, neurofibromatosis type 1, fragile X syndrome, syndromes with neonatal hypoglycemia, Simpson-Golabi-Behmel syndrome, hemihyperplasia, Sturge-Weber syndrome, Bannayan-Riley-Ruvalcaba/Cowden syndrome, macrocephaly-autism syndrome, PEHO syndrome, chromosomal syndromes, and other miscellaneous syndromes.