Klippel-Trenaunay and Sturge-Weber overlap syndrome with phakomatosis pigmentovascularis

CHOROIDAL MELANOMA IN PHAKOMATOSIS PIGMENTOVASCULARIS WITH OVERLAPPING STURGE-WEBER SYNDROME AND KLIPPEL-TRENAUNAY SYNDROME

PURPOSE

To present the rare occurrence of choroidal melanoma in an adult patient with phakomatosis pigmentovascularis and an overlap of Sturge-Weber syndrome and Klippel-Trenaunay syndrome.

METHODS

Observational case report.

RESULTS

A 75-year-old White woman with nevus flammeus involving the left forehead, periorbital area, cheek, chin, upper limb, and trunk, along with hemihypertrophy of the left side of the face and left upper limb, presented for evaluation of an intraocular mass in the left eye. Anterior examination of the left eye showed diffuse episcleral and iris melanocytosis. Fundus examination of the left eye showed diffuse choroidal melanocytosis and an elevated choroidal lesion. B-scan ultrasonography demonstrated a hollow lesion, and the patient was diagnosed with choroidal melanoma in the left eye in the setting of phakomatosis pigmentovascularis with overlap of Sturge-Weber syndrome and Klippel-Trenaunay syndrome. Fine-needle aspiration biopsy confirmed the diagnosis, and Iodine 125 plaque radiotherapy was performed.

CONCLUSION

Individuals with clinical features suggestive of phakomatosis pigmentovascularis, Sturge-Weber syndrome, or Klippel-Trenaunay syndrome should undergo a complete ophthalmological evaluation for the presence of ocular melanocytosis and uveal melanoma.

Blue naevi and the blue tumour spectrum

Blue naevi (BN) form a wide group of benign dermal melanocytic proliferations. They are genetically distinct from common and Spitz naevi with frequent hotspot mutations occurring in Gαq genes. Clinically, BN display a female predominance, elective sites of emergence and a great variety of subtypes related to specific regions of the skin linked to early embryological genetic events. Histologically, most BN are located in the dermis with small, bland, spindled and dendritic pigmented melanocytes within a fibrous background. Variation in tumour volume, fibrosis, and melanin pigment load can be broad. A growth in size and cellularity can occur within a subset of tumours as they acquire the morphological features of cellular blue naevi, with a biphasic architecture associating a dendritic blue naevus morphology near the surface, and deep vertical cellular expansions of medium-sized, bland melanocytes often reaching the subcutis. Sclerosing and myxoid variants can be observed either as individual or combined modifications that can add complexity to an otherwise straightforward diagnosis. Malignant progression of a cellular blue naevus is exceptional with an intermediate stage named atypical cellular blue naevus. Malignant blue melanomas are fast growing, large, pigmented tumours with most often obvious features of malignancy. However, they are difficult to separate from other malignant dermal melanocytic proliferations. Herein, we will extensively detail and illustrate the clinical, histological and genetic features of the vast spectrum of blue naevi and related entities in the skin.

Sturge-Weber Syndrome: A Review of Pathophysiology, Genetics, Clinical Features, and Current Management Approache

Sturge-Weber syndrome (SWS) is a congenital, sporadic, and rare neurocutaneous disorder, characterized by the presence of a facial port-wine birthmark (PWB), glaucoma, and neurological manifestations including leptomeningeal angiomatosis and seizures. It is caused by a postzygotic, somatic, gain-of-function variant of the GNAQ gene, and more recently, the GNA11 gene in association with distinctive clinical features. Neuroimaging can help identify and stratify patients at risk for significant complications allowing closer follow-up; although no presymptomatic treatment has been demonstrated to be effective to date, these patients could benefit from early treatment and/or supportive interventions. Choroid plexus (CP) thickness measurements in brain magnetic resonance imaging (MRI) have a high sensitivity and specificity for early and incipient changes in SWS. In contrast, the absence of pathologic findings makes it possible to rule out associated neurological involvement and leads to periodical observation, with new imaging studies only in cases of new clinical signs/symptoms. Periodic ophthalmological examination is also recommended every 3 months during the first year and yearly afterwards to monitor for glaucoma and choroidal hemangiomas. Treatment for SWS depends on the extent and areas that are affected. These include laser surgery for PWB, anticonvulsants in the case of brain involvement, with either seizures or abnormal EEG, and medical treatment or surgery for glaucoma. Sirolimus has been used in a limited number of patients and appears to be a safe and potentially effective treatment for cutaneous and extra-cutaneous features, however controlled clinical studies have not been carried out. Better knowledge of GNAQ/GNA11 molecular pathways will help to develop future targeted treatments.

Ocular features in a patient presenting with a rare combination of multiple phakomatoses

Phakomatoses are a group of congenital disorders characterised by hamartomatous lesions of the skin as well as the central and peripheral nervous systems. The presence of naevus flammeus or port-wine stain is a characteristic feature of many such disorders including Sturge-Weber syndrome (SWS), Klippel-Trenaunay syndrome (KTS) and Phakomatosis pigmentovascularis (PPV).We describe the ocular findings in a patient with coexisting PPV, SWS and KTS.

Klippel-Trenaunay and Sturge-Weber Overlap Syndrome with KRAS and GNAQ mutations

Patients with combined phenotypes of Sturge-Weber syndrome and Klippel-Trenaunay syndrome have been reported, though the underlying genetic spectrum in these individuals remains to be elucidated. We reported the patient presenting with Klippel-Trenaunay and Sturge-Weber overlap syndrome in mainland China. Histopathologic study confirmed the hemangioma of vein and capillary. Co-existence of a novel somatic KRAS c.182_183 delins TC mutation and GNAQ c.548G>A mutation was identified in the affected skin tissue rather than paired peripheral blood. The somatic mutations of GNAQ and KRAS may affect MAPK-ERK signaling pathway, resulting in endothelial anomaly and blood vessel malformation.

Extracutaneous manifestations in phacomatosis cesioflammea and cesiomarmorata: Case series and literature review

Phacomatosis pigmentovascularis (PPV) comprises a family of rare conditions that feature vascular abnormalities and melanocytic lesions that can be solely cutaneous or multisystem in nature. Recently published work has demonstrated that both vascular and melanocytic abnormalities in PPV of the cesioflammea and cesiomarmorata subtypes can result from identical somatic mosaic activating mutations in the genes GNAQ and GNA11. Here, we present three new cases of PPV with features of the cesioflammea and/or cesiomarmorata subtypes and mosaic mutations in GNAQ or GNA11. To better understand the risk of potentially occult complications faced by such patients we additionally reviewed 176 cases published in the literature. We report the frequency of clinical findings, their patterns of co-occurrence as well as published recommendations for surveillance after diagnosis. Features assessed include: capillary malformation; dermal and ocular melanocytosis; glaucoma; limb asymmetry; venous malformations; and central nervous system (CNS) anomalies, such as ventriculomegaly and calcifications. We found that ocular findings are common in patients with phacomatosis cesioflammea and cesiomarmorata. Facial vascular involvement correlates with a higher risk of seizures (p = .0066). Our genetic results confirm the role of mosaic somatic mutations in GNAQ and GNA11 in phacomatosis cesioflammea and cesiomarmorata. Their clinical and molecular findings place these conditions on a clinical spectrum encompassing other GNAQ and GNA11 related disorders and inform recommendations for their management.

Mosaic Activating Mutations in GNA11 and GNAQ Are Associated with Phakomatosis Pigmentovascularis and Extensive Dermal Melanocytosis

Common birthmarks can be an indicator of underlying genetic disease but are often overlooked. Mongolian blue spots (dermal melanocytosis) are usually localized and transient, but they can be extensive, permanent, and associated with extracutaneous abnormalities. Co-occurrence with vascular birthmarks defines a subtype of phakomatosis pigmentovascularis, a group of syndromes associated with neurovascular, ophthalmological, overgrowth, and malignant complications. Here, we discover that extensive dermal melanocytosis and phakomatosis pigmentovascularis are associated with activating mutations in GNA11 and GNAQ, genes that encode Gα subunits of heterotrimeric G proteins. The mutations were detected at very low levels in affected tissues but were undetectable in the blood, indicating that these conditions are postzygotic mosaic disorders. In vitro expression of mutant GNA11^R183C and GNA11^Q209L in human cell lines demonstrated activation of the downstream p38 MAPK signaling pathway and the p38, JNK, and ERK pathways, respectively. Transgenic mosaic zebrafish models expressing mutant GNA11^R183C under promoter mitfa developed extensive dermal melanocytosis recapitulating the human phenotype. Phakomatosis pigmentovascularis and extensive dermal melanocytosis are therefore diagnoses in the group of mosaic heterotrimeric G-protein disorders, joining McCune-Albright and Sturge-Weber syndromes. These findings will allow accurate clinical and molecular diagnosis of this subset of common birthmarks, thereby identifying infants at risk for serious complications, and provide novel therapeutic opportunities.

Neurocutaneous syndromes

Neurocutaneous syndromes (or phakomatoses) are a diverse group of congenital disorders that encompass abnormalities of neuroectodermal and, sometimes, mesodermal development, hence commonly involving the skin, eye, and central nervous system. These are often inherited conditions and typically present in early childhood or adolescence. Some of the abnormalities and clinical symptoms may, however, be progressive, and there is an increased risk of neoplastic formation in many of the syndromes. As a group, neurocutaneous syndromes are characterized by distinctive cutaneous stigmata and neurologic symptomology, the latter often representing the most devastating and debilitating features of these diseases. Many of these syndromes are markedly heterogeneous in nature as they affect many organ systems. Given the incurable nature of these conditions and the broad spectrum of pathologies they comprise, treatments vary on a case-by-case basis and tend to be palliative rather than curative. With the advances in molecular genetics, however, greater understanding of biologic functions of the gene products and the correlative phenotypic expression is being attained, and this knowledge may guide future therapeutic developments. This chapter focuses on the cutaneous and neurologic pathology with emphasis on neuroimaging of selective neurocutaneous syndromes, including tuberous sclerosis, Sturge-Weber syndrome, Klippel-Trenaunay syndrome, ataxia-telangiectasia, and incontinentia pigmenti.

Klippel-Trenaunay and Sturge-Weber overlapping syndrome in a Saudi boy

Sturge-Weber Syndrome (SWS) is a rare, sporadic neurocutaneous disorder. It is typically characterized by unilateral, posterior leptomeningeal angiomas that calcify, glaucoma, and facial portwine tains. Klippel-Trenaunay syndrome (KTS) is a rare congenital syndrome characterized by ipsilateral cutaneous capillary malformations, venous varicosities, and bony or soft tissue overgrowth of the affected limbs. The clinical, neuroradiological features as well as the outcome of a Saudi boy who was referred to the Division of Pediatric Neurology, King Saud University Medical City, Riyadh, Saudi Arabia, with intractable focal seizure and left-sided hemiparesis who was eventually diagnosed with combined SWS and KTS is described here. The rare coexistence of SWS and KTS should be suspected in a child presenting with neurological manifestation such as epilepsy, mental sub normality, or hemiparesis, with port-wine staining or capillary hemangioma and enlarged limbs. Awareness may help in improving the quality of life and survival of these patients.

Evolution of a symptomatic diffuse developmental venous anomaly with progressive cerebral atrophy in an atypical case of Sturge-Weber syndrome

A 2-year-old boy had glaucoma, bilateral facial haemangioma and widespread blue nevi on the trunk and extremities since birth. Dilated medullary veins were detected in the left cerebral periventricular white matter on magnetic resonance imaging (MRI). Macrocephaly and delayed psychomotor development were observed during late infancy, and susceptibility-weighted angiography revealed an extensive developmental venous anomaly with multiple caput medusae throughout bilateral hemispheres, accompanied by periventricular hyperintense alterations on MRI and progressive diffuse atrophy of the cerebral mantle with left-sided predominance. Hypoperfusion in the left cerebral and cerebellar hemisphere was also uncovered. No meningeal haemangioma was observed. This patient may represent a novel subgroup of phakomatosis cases that can be regarded as a variant of Sturge-Weber syndrome.