Macrocephaly-cutis marmorata telangiectatica congenita: seven cases including two with unusual cerebral manifestations

Megalencephaly-Capillary Malformation-Polymicrogyria Syndrome (MCAP): A Rare Dynamic Genetic Disorder

Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is an uncommon malformation syndrome, characterized by primary megalencephaly, capillary malformations of the midline face and body, or distal limb anomalies such as syndactyly and polymicrogyria. Herein, we report a young male child, who presented with complaints of increasing head size, delay in speech, and one episode of focal seizure with distinctive morphological and neuroradiological manifestations which led to the diagnosis of MCAP. We have also reviewed recently published literature and the various diagnostic criteria proposed by authors to achieve the early clinical diagnosis of these patients in the outpatient department.

Clinical and neuroimaging findings in 33 patients with MCAP syndrome: A survey to evaluate relevant endpoints for future clinical trials

Megalencephaly-CApillary malformation-Polymicrogyria (MCAP) syndrome results from somatic mosaic gain-of-function variants in PIK3CA. Main features are macrocephaly, somatic overgrowth, cutaneous vascular malformations, connective tissue dysplasia, neurodevelopmental delay, and brain anomalies. The objectives of this study were to describe the clinical and radiological features of MCAP, to suggest relevant clinical endpoints applicable in future trials of targeted drug therapy. Based on a French collaboration, we collected clinical features of 33 patients (21 females, 12 males, median age of 9.9 years) with MCAP carrying mosaic PIK3CA pathogenic variants. MRI images were reviewed for 21 patients. The main clinical features reported were macrocephaly at birth (20/31), postnatal macrocephaly (31/32), body/facial asymmetry (21/33), cutaneous capillary malformations (naevus flammeus 28/33, cutis marmorata 17/33). Intellectual disability was present in 15 patients. Among the MRI images reviewed, the neuroimaging findings were megalencephaly (20/21), thickening of corpus callosum (16/21), Chiari malformation (12/21), ventriculomegaly/hydrocephaly (10/21), cerebral asymmetry (6/21) and polymicrogyria (2/21). This study confirms the main known clinical features that defines MCAP syndrome. Taking into account the phenotypic heterogeneity in MCAP patients, in the context of emerging clinical trials, we suggest that patients should be evaluated based on the main neurocognitive expression on each patient.

One of the First Cases with PIK3CA-related Overgrowth Spectrum (PROS) in Saudi Arabia: A Case Report and Literature Review

PIK3CA-related overgrowth spectrum (PROS) is an umbrella that includes a broad range of rare disorders, ranging from isolated digit enlargement to extensive overgrowth of the limbs, abdomen, or brain. One of these disorders is megalencephaly capillary malformation polymicrogyria syndrome (MCAP), which is characterized by cutaneous capillary malformations, megalencephaly, cortical brain malformations, abnormalities of somatic growth with body and brain asymmetry, developmental delay, and characteristic facial dysmorphism. The diagnosis of PROS syndrome is based on the clinical features of a patient and confirmed by a pathogenic variant in one PIK3CA allele in a biopsy of the affected tissue. However, MCAP may be diagnosed by testing a blood or saliva sample. The management of patients with MCAP syndrome includes evaluation after the initial diagnosis, treatment of manifestations, and surveillance for potential complications. To date, there is no curative treatment for patients with MCAP syndrome. Therefore, reporting such cases will help us understand them and thus develop an appropriate treatment for them.

Our patient was a 46-month-old boy, who is diagnosed with MCAP syndrome. The diagnosis was based on clinical presentation, imaging studies, and whole-exome sequencing (WES). Clinically, the patient had speech and developmental delay, macrocephaly, joint hyperlaxity, unsteady gait, and subtle dysmorphic facial features. The facial features include low-set ears, frontal bossing, depressed nasal bridge, and bilateral esotropia. MRI studies showed megalocephaly, bilateral perisylvian polymicrogyria, bilateral peri-regional, high T2 signal intensities, and cerebellar tonsil ectopia with crowding of the posterior fossa. Finally, the diagnosis was confirmed by WES, which detected changes in the PIK3CA gene. The patient is on overgrowth protocol for PIK3CA, which includes alpha-fetoprotein and abdominal ultrasound every three months until the age of eight years.

To the best of our knowledge, this is one of the first cases of PROS in Saudi Arabia, which illustrates the classical findings of MCAP syndrome. Further studies and investigations on PROS syndrome are needed to aid in making a definitive classification and treatment of such complex and rare diseases.

Unilateral vestibular schwannoma and meningiomas in a patient with PIK3CA-related segmental overgrowth: Co-occurrence of mosaicism for 2 rare disorders

A 28-year-old female with PIK3CA-related segmental overgrowth presented with headaches. She also had a unilateral vestibular schwannoma (VS), as well as 3 small (<2 cm) meningiomas, which according to the Manchester consensus diagnostic criteria for neurofibromatosis 2 (NF2) is sufficient for a clinical diagnosis. Analysis of blood revealed a mosaic PIK3CA c.2740G>A (p.Gly914Arg) mutation, confirming the diagnosis of PIK3CA-related overgrowth, but no mutations in NF2 were detected. Although VS has not previously been reported in PIK3CA-related segmental overgrowth, meningiomas have, raising the question of whether this patient's VS and meningiomas represent coincidental NF2 or phenotypic extension of her overgrowth syndrome. Genetic analysis of the VS revealed a heterozygous NF2 mutation c.784C>T (p.Arg262Ter) and loss of a portion of 22q, including NF2, SMARCB1, and LZTR1 genes. These results suggest that the patient has 2 different mosaic disorders, NF2 and PIK3CA-related overgrowth. The PIK3CA mutation was also present in the VS. Confirmation of the clinical diagnosis of mosaic NF2 in this patient has implications for monitoring and highlights the possibility of co-occurrence of mosaicism for multiple rare disorders in a single patient.

Megalencephaly-capillary malformation-polymicrogyria syndrome: the first case report in Korea

Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP), previously known as macrocephaly-cutis marmorata telangiectatica congenita and macrocephaly-capillary malformation syndrome, is a rare multiple-malformation syndrome that is characterized by progressive megalencephaly, capillary malformations of the midline face and body, or distal limb anomalies such as syndactyly. Herein, we report a female infant case that satisfies the recently proposed criteria of MCAP and describe the distinctive neuroradiological and morphological features. We have also reviewed recently published reports and the diagnostic criteria proposed by various authors in order to facilitate the clinical diagnosis of these children in pediatric neurology clinics.

Severe holocord syrinx in a child with megalencephaly-capillary malformation syndrome

The authors present the case of a child with megalencephaly-capillary malformation syndrome who developed a rapidly progressive holocord syringomyelia that was treated surgically. A 3-year-old boy with megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome presented with several months of right leg weakness, worsening scoliosis, and increased seizures. An MRI study of the brain demonstrated a Chiari I malformation and massively dilated syringomyelia extending from C-2 to the conus medullaris. The patient underwent an urgent suboccipital craniectomy with C1-3 laminectomies to relieve the CSF outflow obstruction with significant clinical improvement. Surgery was complicated by bleeding from intracranial vascular malformations. This report describes a very rapidly developing, massive holocord syringomyelia related to CSF obstruction due to an unusual congenital brain malformation and associated vascular overgrowth at the site. Serial, premorbid MRI studies demonstrated the very rapid progression from no Chiari malformation, to progressively greater cerebellar tonsillar herniation, to holocord syrinx. This complication has never been reported in MCAP syndrome and should be considered in any affected MCAP patient with a progressive neurological decline, even if previous spine imaging findings were normal. Surgical complications due to hemorrhage also need to be considered in this vascular brain malformation.

Sudden death in a case of megalencephaly capillary malformation associated with a de novo mutation in AKT3

INTRODUCTION

Megalencephaly capillary malformation (MCAP) is a syndrome involving brain overgrowth, characterized by megalencephaly, capillary malformations, asymmetric growth, polymicrogyria, polydactyly, and syndactyly. Cerebellar tonsillar herniation (CTH) and ventriculomegaly are also observed in over half the patients with this syndrome. Early sudden death has been reported in MCAP, but its causes and the surgical strategies for its prevention remain unclear.

CASE REPORT

Here, we report on a patient with MCAP who died suddenly at 5 months of age. He presented with progressive macrocephaly and hypotonia. MRI performed at 4 months of age showed tight posterior fossa, bilateral perisylvian polymicrogyria, enlargement of the straight sinus, and a thickened corpus callosum. However, since the patient did not exhibit capillary malformation, polydactyly, or syndactyly, a definitive diagnosis of MCAP could not be made. He died suddenly while asleep at home 1 month later. The sudden death of MCAP patients was previously attributed to CTH, convulsion, or arrhythmia. In this case, progressive cerebellar enlargement appeared to be the underlying cause. After the patient's death, using his preserved DNA, a missense mutation in the AKT3 gene was identified. Vakt murine thymoma viral oncogene homologue (AKT) is a serine-threonine kinase that functions in the mammalian target of rapamycin (mTOR) pathway and plays an important role in cell proliferation.

CONCLUSION

Accurate early diagnosis, including imaging and genetic analyses, and the recognition and treatment of critical conditions are required to prevent the sudden death of patients with MCAP.

Strokelike episodes and cutis marmorata telangiectatica congenita

We report the case of a boy with cutis marmorata telangiectatica congenita, strokelike episodes, and a pinpoint stenosis of the left internal carotid artery. To our knowledge, this is the first report of a stenosis of an intracranial artery in a patient with cutis marmorata telangiectatica congenita.

Diffuse capillary malformation with overgrowth: a clinical subtype of vascular anomalies with hypertrophy

BACKGROUND

Categorization of vascular anomalies with overgrowth is evolving rapidly with the aid of massively parallel genomic sequencing; however, accurate clinical diagnosis is still essential. We identified a group of patients with an extensive, diffuse, reticulate capillary malformation (CM) and variable hypertrophy without major complications.

OBJECTIVE

We sought to study a subset of patients with diffuse CM to better define prognosis and management.

METHODS

Chart review identified 73 patients with diffuse CM who did not fit the criteria for known disorders with CM and/or overgrowth.

RESULTS

Soft-tissue or bony overgrowth did not correlate with location, morphology, or intensity of the vascular stain. Patients required periodic follow-up to monitor for leg length discrepancy. They were found to exhibit normal neurologic development and proportionate overgrowth rather than progressive, disproportionate asymmetry or vascular complications.

LIMITATIONS

This retrospective review was limited to observations documented at clinic visits; these patients require long-term assessment. Further studies are necessary to accurately assess Wilms tumor risk and clinical outcomes in older adults.

CONCLUSION

We propose the term "diffuse capillary malformation with overgrowth" to designate this extensive reticular vascular staining with proportionate overgrowth. We differentiate diffuse capillary malformation with overgrowth from other disorders with CM and hypertrophy.

Macrocephaly-capillary malformation syndrome in a newborn with tetralogy of fallot and sagittal sinus thrombosis

Macrocephaly-capillary malformation syndrome is characterized by cutaneous vascular malformations with associated anomalies as macrocephaly, macrosomia, hemihypertrophy, hypotonia, developmental delay, lax joints, loose skin, polysyndactyly, and neuroimaging abnormalities. We present a newborn with a prenatal diagnosis of macrosomia and tetralogy of Fallot. He also had macrocephaly; a high forehead; capillary hemangioma on the forehead, upper lip, and philtrum; generalized loose skin; postaxial polydactyly of both hands and feet, with neuroimaging findings of polymicrogyria and thrombosis in sagittal sinus and sinus rectus. His condition was diagnosed as macrocephaly-capillary malformation syndrome in the neonatal period and he died suddenly during sleep at 6 months of age. The clinical course in this syndrome is not as benign as was previously thought. Careful follow-up of these patients with particular emphasis on neuroradiologic and cardiologic evaluation might help decrease the risk of sudden death and to improve long-term outcome.

Megalencephaly-capillary malformation (MCAP) and megalencephaly-polydactyly-polymicrogyria-hydrocephalus (MPPH) syndromes: two closely related disorders of brain overgrowth and abnormal brain and body morphogenesis

The macrocephaly-capillary malformation syndrome (M-CM), which we here propose to rename the megalencephaly-capillary malformation syndrome (MCAP; alternatively the megalencephaly-capillary malformation-polymicrogyria syndrome), and the more recently described megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH) are two megalencephaly (MEG) disorders that involve a unique constellation of physical and neuroimaging anomalies. We compare the features in 42 patients evaluated for physical and neuroimaging characteristics of MCAP and MPPH and propose a more global view of these syndromes based on classes of developmental abnormalities that include primary MEG and growth dysregulation, developmental vascular anomalies (primarily capillary malformations), distal limb anomalies (such as syndactyly and polydactyly), cortical brain malformations (most distinctively polymicrogyria, PMG), and variable connective tissue dysplasia. Based on these classes of developmental abnormalities, we propose that MCAP diagnostic criteria include progressive MEG with either vascular anomalies or syndactyly. In parallel, we propose that MPPH diagnostic criteria include progressive MEG and PMG, absence of the vascular anomalies and syndactyly characteristic of MCAP, and absence of brain heterotopia.

Macrocephaly-capillary malformation: Analysis of 13 patients and review of the diagnostic criteria

Macrocephaly-capillary malformation (M-CM) is a genetic syndrome of unknown etiology characterized by an enlarged head circumference and patchy, reticular capillary malformation. We describe the clinical features of 13 cases, report on the genome-wide Copy Number Variation characterization of these patients, analyze the main clinical features of this syndrome and propose a modification of the current diagnostic criteria: the inclusion of both overgrowth/asymmetry and neuroimaging alterations as major criteria.

[Cutis marmorata telangiectatica congenita]

Cutis marmorata telangiectatica congenita (CMTC) is a rare cutaneous condition in newborns. The lesions form a red or purplish network, sometimes with dilated veins and atrophic areas. Multiple malformations may be associated with it, in particular in infants with macrocephaly. These cutaneous lesions may improve, disappear or remain stable. The appearance is characteristic and diagnosis is based on the clinical picture.

Current concepts of polymicrogyria

Polymicrogyria is one of the most common malformations of cortical development. It has been known for many years and its clinical and MRI manifestations are well described. Recent advances in imaging, however, have revealed that polymicrogyria has many different appearances on MR imaging, suggesting that is may be a more heterogeneous malformation than previously suspected. The clinical and imaging heterogeneity of polymicrogyria is explored in this review.

Endoscopic third ventriculostomy to treat hydrocephalus associated with macrocephaly-cutis marmorata telangiectatica congenita

Macrocephaly-cutis marmorata telangiectatica congenita is a rare overgrowth syndrome commonly associated with hydrocephalus. Although the pathophysiological characteristics of the hydrocephalus in this syndrome is not fully known, previous reports have described its treatment with ventriculoperitoneal shunt placement. The authors describe 2 cases of macrocephaly-cutis marmorata telangiectatica congenita successfully treated for progressive hydrocephalus with endoscopic third ventriculostomy. Both patients experienced clinical and radiographic stabilization following treatment, and these findings offer insight into the pathophysiology of the hydrocephalus and its ideal management.

Tetralogy of Fallot associated with macrocephaly-capillary malformation syndrome: a case report and review of the literature

Introduction

Macrocephaly-capillary malformation syndrome is characterized by cutaneous vascular lesions, including cutis marmorata telangiectatica and hemangiomas, associated with congenital anomalies, including macrocephaly, macrosomia, asymmetry and mental retardation. In addition to these cardinal signs, several other clinical conditions have been reported in people with this condition. However, to the best of our knowledge, the presence of tetralogy of Fallot has not previously been reported in association with this syndrome.

Case presentation

We present a case of a Mexican newborn girl with tetralogy of Fallot associated with macrocephaly-capillary malformation. We discuss the clinical treatment of the patient and its consequences.

Conclusion

Since physiologic cutis marmorata is a common condition in newborns, the information provided in this report could be helpful in future cases in preventing severe clinical consequences or sudden death in patients with similar symptoms.

Significant overlap and possible identity of macrocephaly capillary malformation and megalencephaly polymicrogyria-polydactyly hydrocephalus syndromes

We report on three patients with macrocephaly and polymicrogyria, and additional anomalies seen in megalencephaly polymicrogyria-polydactyly hydrocephalus (MPPH) and macrocephaly capillary malformation (MCM) syndromes. Based on their characteristic brain malformations they were originally diagnosed with MPPH. In one patient the phenotype evolved during early infancy, and ultimately resulted in a diagnosis of MCM. A second was prenatally diagnosed with MPPH, but postnatally visualized capillary malformations led to a diagnosis of MCM. In a third, the original MPPH diagnosis was reconsidered after a critical review revealed additional subtle findings suggestive of MCM. Characteristic brain malformations are thought to distinguish between MPPH with perisylvian polymicrogyria, and MCM with megalencephaly with Chiari 1 malformation. However, polymicrogyria was reported in a significant number of patients with MCM. Conversely, upon review of imaging studies of patients with MPPH, we noted progressive crowding of the posterior fossa and acquired tonsillar herniation, a process deemed characteristic for MCM. Thus, neither polymicrogyria nor acquired tonsillar herniation are distinguishing features, and occur in both disorders. In addition to brain abnormalities, shared findings include cognitive impairment, coarse facial features and postaxial polydactyly. Facial nevus flammeus and cutis marmorata are most noticeable in infancy, and ligamentous laxity and redundant soft tissue are somewhat subjective findings. While asymmetric overgrowth is considered typical for MCM, it is not universally present. These variable and subtle findings can be identified in patients with MPPH. We propose that MPPH and MCM may not represent distinct entities and that the term MPPH-CM syndrome be used to describe this spectrum.

Macrocephaly-capillary malformation: a report of three cases and review of the literature

Macrocephaly-Cutis Marmorata Telangiectatica Congenita (M-CMTC) is a rare syndrome that was first delineated as distinct from Cutis Marmorata Telangiectatica Congenita (CMTC) in 1997. Since that time, there have been over 75 cases reported in the literature, though few are in the dermatology literature. The syndrome is characterized by macrocephaly, neonatal hypotonia, developmental delay, segmental overgrowth, syndactyly, asymmetry, connective tissue defects, and vascular stains. We report three new patients seen at the University of Miami Genodermatoses Clinic with features of M-CMTC. We believe the skin findings in our patients and in the previously published cases of M-CMTC are more consistent with capillary malformations rather than true CMTC. Therefore, we agree with recent publications that this condition be renamed Macrocephaly-Capillary Malformation (M-CM). The differential diagnoses for patients with M-CMTC include Klippel Trenaunay Syndrome (KTS) and Proteus or Proteus-like syndromes. Given the significant prognostic and likely genetic differences among these conditions it is important to distinguish M-CMTC from these syndromes.

Consistent chromosome abnormalities identify novel polymicrogyria loci in 1p36.3, 2p16.1-p23.1, 4q21.21-q22.1, 6q26-q27, and 21q2

Polymicrogyria is a malformation of cortical development characterized by loss of the normal gyral pattern, which is replaced by many small and infolded gyri separated by shallow, partly fused sulci, and loss of middle cortical layers. The pathogenesis is unknown, yet emerging data supports the existence of several loci in the human genome. We report on the clinical and brain imaging features, and results of cytogenetic and molecular genetic studies in 29 patients with polymicrogyria associated with structural chromosome rearrangements. Our data map new polymicrogyria loci in chromosomes 1p36.3, 2p16.1-p23, 4q21.21-q22.1, 6q26-q27, and 21q21.3-q22.1, and possible loci in 1q44 and 18p as well. Most and possibly all of these loci demonstrate incomplete penetrance and variable expressivity. We anticipate that these data will serve as the basis for ongoing efforts to identify the causal genes located in these regions.

Neuroimaging findings in macrocephaly-capillary malformation: a longitudinal study of 17 patients

Here, we report the neuroimaging findings and neurological changes in 17 unpublished patients with Macrocephaly-Capillary Malformation (M-CM). This syndrome has been traditionally known as Macrocephaly-Cutis Marmorata Telangiectatica Congenita (M-CMTC), but we explain why M-CM is a more accurate term for this overgrowth syndrome. We analyzed the 17 patients with available brain MRI or CT scans and compared their findings with features identified by a comprehensive review of published cases. White matter irregularities with increased signal on T2-weighted images were commonly observed findings. A distinctive feature in more than half the patients was cerebellar tonsillar herniation associated with rapid brain growth and progressive crowding of the posterior fossa during infancy. In four such cases, we confirmed that the tonsillar herniation was an acquired event. Concurrently, with the development of these findings, ventriculomegaly (frequently obstructive) and dilated dural venous sinuses were observed in conjunction with prominent Virchow-Robin spaces in many of those in whom cerebellar tonsil herniation had developed. We postulate that this constellation of unusual features suggests a dynamic process of mechanical compromise in the posterior fossa, perhaps initiated by a rapidly growing cerebellum, which leads to congestion of the venous drainage with subsequently compromised cerebrospinal fluid reabsorption, all of which increases the posterior fossa pressure and leads to acquired tonsillar herniation. We make a distinction between congenital Chiari I malformation and acquired cerebellar tonsil herniation in this syndrome. We also observed numerous examples of abnormal cortical morphogenesis, including focal cortical dysplasia, polymicrogyria which primarily involved the perisylvian and insular regions, and cerebral and/or cerebellar asymmetric overgrowth. Other findings included a high frequency of cavum septum pellucidum or vergae, thickened corpus callosum, prominent optic nerve sheaths and a single case of venous sinus thrombosis. One patient was found to have a frontal perifalcine mass resembling a meningioma at age 5 years. This is the second apparent occurrence of this specific tumor in M-CM.

Surgical management of cerebellar tonsillar herniation in three patients with macrocephaly-cutis marmorata telangiectatica congenita. Report of three cases

The authors report on three patients with a congenital brain overgrowth syndrome, macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC), who experienced neurological sequelae associated with herniation of the cerebellar tonsils through the foramen magnum. In two of these patients, the authors document postnatal brain overgrowth that contributed to recurrent descent of the cerebellar tonsils and complicated the surgical treatment in one of the patients. The authors address the neurosurgical concerns related to this syndrome with special attention to acquired tonsillar ectopia and postulate that some patients may be at risk for progressive tonsillar herniation and consequent neurological symptoms due to cerebellar overgrowth. Ectopic cerebellar tonsils have been reported previously in cases of M-CMTC, and this phenomenon may be a secondary event associated with brain overgrowth rather than due to a congenitally small posterior fossa.