Two Distinct Types of Speckled Lentiginous Nevi Characterized by Macular versus Papular Speckles

Nevus Spilus With Dermatoheliosis: A Histologic Mimicker of Melanoma in Situ at Melanoma Excision Margins

ABSTRACT

Nevus spilus, or speckled lentiginous nevus, is a relatively common lesion that presents at birth or in early childhood. It consists of a background tan patch, which appears similar to a café au lait macule or lentigo simplex on histology, studded with various types of nevi. Rarely, these nevi can undergo malignant transformation to melanoma. When melanoma develops within a heavily photodamaged nevus spilus, evaluating excision margins may be challenging because the combined histologic features of nevus spilus and severe dermatoheliosis can mimic melanoma in situ. We report a case of an elderly man with extensive sun damage who developed malignant melanoma within an occult nevus spilus, resulting in multiple excisions with false-positive margins.

PTPN11 Mosaicism Causes a Spectrum of Pigmentary and Vascular Neurocutaneous Disorders and Predisposes to Melanoma

Phakomatosis pigmentovascularis is a diagnosis that denotes the coexistence of pigmentary and vascular birthmarks of specific types, accompanied by variable multisystem involvement, including CNS disease, asymmetrical growth, and a predisposition to malignancy. Using a tight phenotypic group and high-depth next-generation sequencing of affected tissues, we discover here clonal mosaic variants in gene PTPN11 encoding SHP2 phosphatase as a cause of phakomatosis pigmentovascularis type III or spilorosea. Within an individual, the same variant is found in distinct pigmentary and vascular birthmarks and is undetectable in blood. We go on to show that the same variants can cause either the pigmentary or vascular phenotypes alone, and drive melanoma development within pigmentary lesions. Protein structure modeling highlights that although variants lead to loss of function at the level of the phosphatase domain, resultant conformational changes promote longer ligand binding. In vitro modeling of the missense variants confirms downstream MAPK pathway overactivation and widespread disruption of human endothelial cell angiogenesis. Importantly, patients with PTPN11 mosaicism theoretically risk passing on the variant to their children as the germline RASopathy Noonan syndrome with lentigines. These findings improve our understanding of the pathogenesis and biology of nevus spilus and capillary malformation syndromes, paving the way for better clinical management.

Noninvasive imaging exploration of phacomatosis pigmentokeratotica using high-frequency ultrasound and optical coherence tomography: Can biopsy of PPK patients be avoided?

BACKGROUND

Phacomatosis pigmentokeratotica (PPK) is a distinct and rare type of epidermal nevus syndrome characterized by coexisting nonepidermolytic organoid sebaceous nevus (SN) with one or more speckled lentiginous nevi (SLN). Atypical nevi including compound Spitz and compound dysplastic may manifest within regions of SLN. Patients with PPK, or similar atypical nevus syndromes, may be subject to a significant lifetime number of biopsies, leading to pain, scarring, anxiety, financial burden, and decreased quality of life. The current literature includes case reports, genetics, and associated extracutaneous symptoms of PPK, but use of noninvasive imaging techniques have not been explored. We aim to investigate the value of high-frequency ultrasound (HFUS) and optical coherence tomography (OCT) in discriminating morphological features of pigmented lesions and nevus sebaceous within one patient with PPK.

MATERIALS AND METHODS

Two modalities, (1) HFUS imaging, based on acoustic properties and (2) OCT imaging, based on optical properties, were used to image a patient with PPK. Benign pigmented lesions, which may raise clinical suspicion for significant atypia, and nevus sebaceous, were selected on different areas of the body to be studied.

RESULTS

Five pigmented lesions and one area of nevus sebaceous were imaged and analyzed for noninvasive features. Distinct patterns of hypoechoic features were seen on HFUS and OCT.

CONCLUSION

HFUS provides a deep view of the tissue, with ability to differentiate gross structures beneath the skin. OCT provides a smaller penetration depth and a higher resolution. We have described noninvasive features of atypical nevi and nevus sebaceous on HFUS and OCT, which indicate benign etiology.

Treatment of Nevus Spilus with dual-wavelength copper vapor laser

Introduction. Speckled lentiginous nevus or Nevus Spilus (NS) is a congenital or acquired melanocytic nevus. NS appears as dark hyperpigmented macules or papules interspersed in the lentigo-like hyperpigmentation patch. Surgical methods for removing NS, primarily on the skin with a thin dermis, are associated with the risk of disruption of its structure or scarring. The use of single wavelength laser irradiation allowed achieving pronounced bleaching of the NS area with such side effects as scars, post-inflammatory hyperpigmentation, and relapses in some cases. Side effects could occur due to the lack of complete blood flow in the microvascular bed near the NS. The study aimed to evaluate the efficacy of NS treatment with a dual-wavelength copper vapor laser (CVL). Description of patients and the method of the treatment. Two fair-skinned adult female patients with NS, of medium size and different location, asked to restore the natural colour of the skin in order to get rid of cosmetic defects. NS treatment was carried out using CVL (Yakhroma-Med model, P.N.Lebedev Physical Institute of the Russian Academy of Sciences) during six procedures, an interval of 46weeks. For treatment, we used two-wavelength CVL radiation with average power in the range of 0.60.8W with a power ratio of 3:2 at wavelengths of 511 nm and 578 nm; exposure time: 0.20.3 s. The diameter of the light spot on the skin accounted for 1 mm. Both patients were satisfied with the result of the treatment due to the noticeable blanching of the pigmented skin area after the NS removal. During the following two years, no dark spots or scarring was observed at the NS removal site. Conclusion. Treatment of medium-sized NS using two-wavelength CVL radiation made it possible toeliminate the cosmetic defect without side effects.

Speckled lentiginous nevus: A rare presentation associated with motor neuropathy and muscular atrophy in a child

Speckled lentiginous nevus syndrome has been described in individuals with a speckled lentiginous nevus with rare associated neurologic deficits. Because speckled lentiginous nevus syndrome almost always affects adults, it is not typically considered when evaluating children. We present the first reported case of speckled lentiginous nevus syndrome presenting in a young child with muscle atrophy and motor deficits affecting muscles along the same distribution as the speckled lentiginous nevus.

Mosaic Neurocutaneous Disorders and Their Causes

Neurocutaneous disorders are a heterogeneous group of conditions (mainly) affecting the skin [with pigmentary/vascular abnormalities and/or cutaneous tumours] and the central and peripheral nervous system [with congenital abnormalities and/or tumours]. In a number of such disorders, the skin abnormalities can assume a mosaic patterning (usually arranged in archetypical patterns). Alternating segments of affected and unaffected skin or segmentally arranged patterns of abnormal skin often mirror similar phenomena occurring in extra-cutaneous organs/tissues [eg, eye, bone, heart/vessels, lung, kidney and gut]. In some neurocutaneous syndromes the abnormal mosaic patterning involve mainly the skin and the nervous system configuring a (true) mosaic neurocutaneous disorder; or an ordinary trait of a neurocutaneous disorder is sometimes superimposed by a pronounced linear or otherwise segmental involvement; or, lastly, a neurocutaneous disorder can occur solely in a mosaic pattern. Recently, the molecular genetic and cellular bases of an increasing number of neurocutaneous disorders have been unravelled, shedding light on the interplays between common intra- and extra-neuronal signalling pathways encompassing receptor-protein and protein-to-protein cascades (eg, RAS, MAPK, mTOR, PI3K/AKT and GNAQ pathways), which are often responsible of the mosaic distribution of cutaneous and extra-cutaneous features. In this article we will focus on the well known, and less defined mosaic neurocutaneous phenotypes and their related molecular/genetic bases, including the mosaic neurofibromatoses and their related forms (ie, spinal neurofibromatosis and schwannomatosis); Legius syndrome; segmental arrangements in tuberous sclerosis; Sturge-Weber and Klippel-Trenaunay syndromes; microcephaly/megalencephaly-capillary malformation; blue rubber bleb nevus syndrome; Wyburn-Mason syndrome; mixed vascular nevus syndrome; PHACE syndrome; Incontinentia pigmenti; pigmentary mosaicism of the Ito type; neurocutaneous melanosis; cutis tricolor; speckled lentiginous syndrome; epidermal nevus syndromes; Becker's nevus syndrome; phacomatosis pigmentovascularis and pigmentokeratotica; Proteus syndrome; and encephalocraniocutaneous lipomatosis.

Update on melanocytic nevi in children

A new or changing melanocytic nevus in a child or adolescent often leads to concern in parents and physicians. To avoid undue alarm and unnecessary procedures, dermatologists should be aware of the natural history and clinical spectrum of nevi in pediatric patients, as well as findings that are potentially worrisome in this age group. This review provides an update on melanocytic nevi in children, focusing on their dynamic evolution over time, molecular insights into nevogenesis, and phenotypic markers for increased risk of melanoma in adolescence and adulthood. Special considerations for Spitz nevi and nevi located in particular sites (eg, scalp, acral, genital) are highlighted. Current understanding of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of children with numerous acquired nevi, Spitz nevi, and congenital nevi are also discussed.

Dermoscopy for the pediatric dermatologist part III: dermoscopy of melanocytic lesions

Melanocytic nevi encompass a variety of lesions, including blue, Spitz, congenital, and acquired nevi. These nevi can occasionally manifest clinical morphologies resembling melanoma, and the presence of such nevi in children can elicit anxiety in patients, parents, and clinicians. Dermoscopy has been shown to increase the diagnostic accuracy for melanoma and to help differentiate melanoma from nevi, ultimately aiding in the decision-making process as to whether to perform a biopsy. Dermoscopy is the perfect instrument to use during the evaluation of pigmented skin lesions in children because it is painless and provides important information for the clinician that can assist in formulating appropriate management decisions. This review highlights the most common benign dermoscopic patterns encountered in nevi and discuss the 10 most common dermoscopic structures seen in melanomas. Lesions manifesting a benign dermoscopic pattern and lacking any melanoma-specific structures do not need to be excised and can safely be monitored. In contrast, melanomas will invariably deviate from the benign nevus patterns and will usually manifest at least 1 of the 10 melanoma-specific structures: atypical network, negative network, streaks, crystalline structures, atypical dots and globules, irregular blotch, blue-white veil, regression structures, peripheral brown structureless areas, and atypical vessels. It is important to be cognizant of the fact that melanomas in childhood usually do not manifest the clinical ABCD features. Instead, they are often symmetric, amelanotic, nodular lesions. Although the clinical appearance may not be alarming, with dermoscopy they will invariably manifest at least one melanoma-specific structure, the most common being atypical vascular structures and crystalline structures.

Phacomatosis pigmentokeratotica is caused by a postzygotic HRAS mutation in a multipotent progenitor cell

Phacomatosis pigmentokeratotica (PPK) is a rare epidermal nevus syndrome characterized by the co-occurrence of a sebaceous nevus and a speckled lentiginous nevus. The coexistence of an epidermal and a melanocytic nevus has been explained by two homozygous recessive mutations, according to the twin spot hypothesis, of which PPK has become a putative paradigm in humans. However, the underlying gene mutations remained unknown. Multiple tissues of six patients with PPK were analyzed for the presence of RAS, FGFR3, PIK3CA, and BRAF mutations using SNaPshot assays and Sanger sequencing. We identified a heterozygous HRAS c.37G>C (p.Gly13Arg) mutation in four patients and a heterozygous HRAS c.182A>G (p.Gln61Arg) mutation in two patients. In each case, the mutations were present in both the sebaceous and the melanocytic nevus. In the latter lesion, melanocytes were identified to carry the HRAS mutation. Analysis of various nonlesional tissues showed a wild-type sequence of HRAS, consistent with mosaicism. Our data provide no genetic evidence for the previously proposed twin spot hypothesis. In contrast, PPK is best explained by a postzygotic-activating HRAS mutation in a multipotent progenitor cell that gives rise to both a sebaceous and a melanocytic nevus. Therefore, PPK is a mosaic RASopathy.

Hairy nevus spilus: a case series

Nevus spilus, also known as speckled lentiginous nevus, is a nevoid disorder characterized by hyperpigmented macules or papules scattered over a background of tan pigmentation. Although nevus spilus is mainly of cosmetic concern, malignant melanoma may rarely develop in the lesions. Although classically not mentioned as a hairy nevus, a few reports in literature mention overlying hypertrichosis in lesions of nevus spilus. We hereby report four cases of nevus spilus without malignant change with overlying terminal hairs that arose mainly from the background pigmented area.

Phacomatosis pigmentokeratotica: a further case without extracutaneous anomalies and review of the condition

Epidermal nevus syndrome is the term for the association of an epidermal nevus and extracutaneous anomalies, including neurologic, ophthalmic, and skeletal defects. Epidermal nevus syndromes include different disorders that share the feature of mosaicism. Phacomatosis pigmentokeratotica (PPK) is a distinctive new epidermal nevus syndrome first described in 1996 characterized by the presence of multiple organoid nevi with sebaceous differentiation, a speckled lentiginous nevus, and skeletal and neurologic abnormalities. Only a handful of cases of PPK without extracutaneous manifestations have been reported. We report here an individual with PPK with only cutaneous signs and confirm this distinctive syndrome has two subtypes according to the presence or absence of extracutaneous involvement.

Spitz nevi arising in speckled lentiginous nevus: clinical, histologic, and molecular evaluation of two cases

Spitz nevi are small dome-shaped nodules that sometimes arise in areas of preexisting hyperpigmentation, such as a speckled lentiginous nevus (nevus spilus), where they present a diagnostic dilemma. We report clinical, histopathological, and molecular findings of two cases of multiple Spitz nevi arising in a speckled lentiginous nevus. We used immunohistochemistry to assess expression of Ki-67, epidermal growth factor receptor, vascular endothelial growth factor, and RelA in two cases of Spitz nevi arising in a speckled lentiginous nevus. We observed rare staining for the proliferative marker Ki-67, but positive staining for the growth and antiapoptotic factors epidermal growth factor receptor, vascular endothelial growth factor, and RelA. Characterization of the molecular phenotype of Spitz nevi arising in speckled lentiginous nevi may provide a useful adjunct to long-term monitoring in this rare but difficult clinical presentation.

Widespread nevus spilus associated with torsion dystonia: a case report

Usually speckled lentiginous nevus or nevus spilus is a small solitary lesion consisting of a light tan patch with numerous dark brown macules or papules (or both) within it. It is occasionally associated with complex birth defects such as phacomatosis pigmentovascularis, phacomatosis pigmentokeratotica, or speckled lentiginous nevus syndrome. Uncommon presentations include large segmental lesions that may or may not be systematized and can sometimes be associated with other anomalies. We hereby report a 6-year-old Caucasian patient with systematized nevus spilus associated with torsion dystonia, a combination not published thus far.

Congenital melanocytic nevi

The relative risk for melanoma arising within a congenital nevus is related to the size of the lesion. The timing of and clinical presentation of development of melanoma is also related to the size of the lesion. Medical decisions are individualized taking into account the perceived risk of malignancy, psychosocial impact, and anticipated treatment outcome. In this article, the common features of congenital nevi are discussed as well as the potential individual variations and their impact on treatment recommendations.

Congenital melanocytic nevi-when to worry and how to treat: Facts and controversies

Congenital melanocytic nevi (CMN) are evident in 1% to 6% of neonates. In some studies, nevi with clinical, dermatoscopic, and histologic features identical to CMN have had a prevalence of more than 15% in older children and adults, possibly reflecting the "tardive" appearance of nevi programmed from birth. There is ongoing debate about the magnitude of the risk of melanoma and other complications associated with CMN of various sizes and the best approach to management of these lesions. We review the natural history of CMN, including proliferative nodules and erosions during infancy, neurotization, and spontaneous regression, and features of variants such as speckled lentiginous and congenital blue nevi. The risk of melanoma arising within small-sized (<1.5 cm) and medium-sized CMN is low (likely <1% over a lifetime) and virtually nonexistent before puberty. Recent data suggest that melanoma (cutaneous or extracutaneous) develops in approximately 5% of patients with a large (>20 cm) CMN, with about half of this risk in the first few years of life. Melanoma and neurocutaneous melanocytosis (NCM) are most likely in patients with CMN that have a final size of >40 cm in diameter, numerous satellite nevi, and a truncal location. One-third of individuals with NCM have multiple medium-sized (but no large) CMN. In patients at risk for NCM, a screening gadolinium-enhanced magnetic resonance imaging, preferably before age 6 months, and longitudinal neurologic assessment are recommended. Management of CMN depends on such factors as the ease of monitoring (more difficult for large, dark, thick nevi) and cosmetic and psychologic benefits of excision or other procedures. CMN require lifelong follow-up. Periodic total body skin examinations are necessary for all patients with large CMN, even when complete resection (often impossible) has been attempted.

Nevus Spilus and Melanoma: Case Report and Review of the Literature

Background:

Nevus spilus is characterized by a pigmented patch with scattered flat or maculopapular speckles. Nevus spilus was first described by Burkley in 1842. Since then, this lesion has been widely debated in the literature, particularly for the possible occurrence of melanoma within the lesion.

Objective:

We describe the case of a 65-year-old female presenting with a nodular achromic melanoma that occurred within a nevus spilus on the left thigh.

Conclusion:

Our observation is consistent with the idea that this entity in some circumstances may have the ability to evolve into a malignant melanoma.

Nevus Spilus with Synchronous Melanomas: Case Report and Literature Review

Background:

Nevus spilus is a rare, acquired, and often large cutaneous lesion consisting of a light brown background macule containing varying numbers of small darker macular or papular areas.

Objective:

Nevus spilus may contain dysplastic melanocytic elements, and there are also reports of melanoma arising from nevus spilus. However, the absolute risk for malignant transformation is not well defined.

Conclusion:

We discuss a case of synchronous melanomas arising from a nevus spilus and potential management recommendations based on a review of the pertinent literature.

Phacomatosis pigmentokeratotica: a follow-up report documenting additional cutaneous and extracutaneous anomalies

This is a follow-up report on a boy with phacomatosis pigmentokeratotica. At the age of 10 years he had, in addition to a sebaceous nevus and a speckled lentiginous nevus, multiple lesions of a collagen nevus localized on the chin and in the lumbar area. On the left shoulder, a small telangiectatic spot was present within the area of the speckled lentiginous nevus. Moreover, hemiatrophy of the left-hand side of the body and hyperhidrosis of the left lumbar area were noted. At the age of 16, the lesions of his collagen nevus had considerably enlarged and showed an arrangement along Blaschko lines. Additional pinhead-sized vascular lesions were noted, with preponderance within the area of the speckled lentiginous nevus in the left scapular region and on his left leg. Moreover, the boy had developed severe arterial hypertension since the age of 13. Angiographic examination showed an aortic stenosis that reached from the aortic arch down to the origin of the renal arteries, necessitating a surgical intervention. From this follow-up report we conclude that phacomatosis pigmentokeratotica may be associated with other cutaneous abnormalities such as linear connective tissue nevus of the collagen type and multiple pinhead-sized angioma-like lesions superimposed on the speckled lentiginous nevus. The associated defects of the large vessels may belong to the component of Schimmelpenning syndrome representing one "half" of phacomatosis pigmentokeratotica, rather than being part of the speckled lentiginous syndrome that forms the other "half" of this twin-spot phenotype.

Pigmented lesions in children: when to worry

PURPOSE OF REVIEW

Although the incidence of melanoma in adolescents and adults has risen dramatically in the past few decades, childhood melanoma remains uncommon. It is therefore important for pediatricians to be aware of the natural history and clinical spectrum of melanocytic nevi in children as well as potentially worrisome features of pigmented lesions.

RECENT FINDINGS

Recent studies have provided insight into the development, evolution and molecular bases of acquired and congenital melanocytic nevi during childhood. This review summarizes the types of melanocytic nevi that are commonly observed in children, environmental (e.g. sun exposure) and genetic (e.g. the familial atypical mole and melanoma syndrome) factors that can contribute to the development of nevi and future risk of melanoma, and phenotypic markers (e.g. numerous acquired nevi or the 'red hair phenotype') that signal the need for periodic total-body cutaneous examinations. Current concepts of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of various types of nevi (including congenital, blue and Spitz nevi) are presented, and data on the clinical presentations and biologic behavior of prepubertal melanoma are discussed.

SUMMARY

Clinical and molecular investigations have helped to better understand the characteristics of melanocytic nevi and define pathways of melanocytic tumorigenesis.

A giant congenital nevus spilus in an 8-year-old girl

Congenital nevus spilus is rare, and the lesion is usually small. This report describes an 8-year-old girl with a giant congenital nevus spilus that involved the left side of her abdomen, perineal area, and left upper thigh. The patient also had a Mongolian spot in the lumbosacral area.