Speckled Lentiginous Nevus 

Updated: Apr 07, 2017
Author: Rossitza Lazova, MD; Chief Editor: Dirk M Elston, MD 

Overview

Background

Speckled lentiginous nevus is a patch of hyperpigmentation that can be seen on any area of the body. This patch contains a variable number of darkly pigmented macules and papules. Some authorities believe that speckled lentiginous nevus is a subtype of congenital melanocytic nevus.[1, 2, 3]

Pathophysiology

Speckled lentiginous nevus may represent a localized defect in neural crest melanoblasts that populate a particular area of the skin. Environmental and genetic factors may also play a role. Mosaicism may be an explanation for the development of zosteriform speckled lentiginous nevus.[4]

Speckled lentiginous nevus can be associated with different disorders. In facial features, anorexia, cachexia, and eye and skin anomalies (FACES) syndrome, cutaneous findings include zosteriform speckled lentiginous nevi. Associated findings also include ichthyosis, Ebstein syndrome (the eponym for congenital downward displacement of the tricuspid valve into the right ventricle), epidermal nevi, nevus sebaceous, scleral pigmentation, segmental neurofibromatosis type I,[5] adult-onset hearing loss, corneal snowflake dystrophy, and hypertrophy of the underlying pectoralis major muscle. In addition, an association with abnormality of the tongue and median nerve paresis have been described.[6, 7]

An association with phacomatosis pigmentovascularis and phacomatosis pigmentokeratotica has also been described.[8, 9, 10, 11, 12]

Speckled lentiginous nevus syndrome has been characterized as a distinct neurocutaneous phenotype where ipsilateral neurological abnormalities are present in association with speckled lentiginous nevus.[6, 7, 8, 9, 11, 12]

Epidemiology

Frequency

United States

In the general population, the prevalence of speckled lentiginous nevi is similar to that of congenital melanocytic nevi, with a prevalence of 0.2-2.3%, depending on age.[13]

International

Speckled lentiginous nevus has been studied in Canadian children of Asian and white European origins, and its prevalence is the same in both ethnic groups.

Race

No racial predilection is noted.

Sex

No sexual predilection is recognized.

Age

Low prevalence rates of up to 0.2% have been reported in series of newborns. Approximately 80% of speckled lentiginous nevi appear at birth or during early infancy. They may present as lightly colored café au lait macules at birth, which later develop background hyperpigmentation and darkly pigmented macules and papules over months, years, or sometimes decades.

The prevalence rate of speckled lentiginous nevus is 1.3-2.1% in school-aged children and adolescents.

In adults, the frequency of speckled lentiginous nevi larger than 1.5 cm in diameter is 2.3%.

Prognosis

Speckled lentiginous nevus is a benign neoplasm. In rare instances of malignant transformation within a speckled lentiginous nevus, morbidity and mortality are dependent on the stage of the secondary malignancy. At least 20 cases of cutaneous melanoma developing within a speckled lentiginous nevus have been reported.[14, 15, 16, 17, 18, 19]

Patient Education

Regular visits to a dermatologist and careful examination with the use of photography should be used for early recognition of atypical features within a speckled lentiginous nevus.

 

Presentation

History

Patients may complain of hyperpigmented or multicolored skin lesions, with colors most often including shades of tan, brown, and black. The lesions are present at birth or noted during the individual's first years of life. Patients may be aware of an increase in the size of the lesions or changes in color over time. Skin distribution varies, with the trunk being the most common site of occurrence. It has also been reported in the oral cavity.[20]

Physical Examination

A variable number of black, brown, or red-brown macules and papules are seen within a patch of tan-to-brown hyperpigmentation. The background pigmented macule or patch is usually 3-6 cm in diameter, but the diameter may vary from 1 cm to more than 60 cm.

See the image below.

A large unilateral speckled lentiginous nevus that A large unilateral speckled lentiginous nevus that contains numerous small dark macules.

The lesions are usually oval, but they can be linear. Some follow the lines of Blaschko or have a sharp demarcation at the midline. An extensive amount of body surface area may be involved.

See the image below.

Extensive speckled lentiginous nevus. Extensive speckled lentiginous nevus.

The macules (speckles) and papules lying within the background patch range from lentigines to junctional, compound, or dermal nevi. Spitz nevi and blue nevi may also occur. The speckles range from 1-9 mm; most commonly, they are 2-3 mm in diameter. To the author's knowledge, deep penetrating nevus occurring within a speckled lentiginous nevus has not been reported.

Causes

Speckled lentiginous nevi may represent a defect in the melanoblasts that populate a localized area of the skin. Genetic and environmental factors may also play a role in their occurrence.

Complications

Malignant melanoma may develop within speckled lentiginous nevus. Predictors of the risk of malignant transformation of a speckled lentiginous nevus have yet to be determined. The surface area, the number of nevi within the speckled lentiginous nevus, and/or the presence of cytologic atypia may be factors that affect the potential for malignant transformation of a speckled lentiginous nevus.

 

DDx

Diagnostic Considerations

In its earliest stage, speckled lentiginous nevus can be confused with a café au lait macule. In agminated melanocytic nevi, the background skin is not hyperpigmented, unlike that in speckled lentiginous nevus. In partial unilateral lentiginosis, multiple lentigines are grouped together on skin that has a normal color.

Differential Diagnoses

 

Workup

Procedures

Biopsy is necessary to rule out cytologic atypia, which may develop in a speckled lentiginous nevus.

Electron microscopic studies show melanosomes that are fully melanized and a few premelanosomes in junctional melanocytes.

Histologic Findings

Increased pigmentation in the basal layer of the epidermis and lentiginous epidermal hyperplasia are present in the background macule or patch of hyperpigmentation; these findings are similar to those of lentigo simplex. See the image below.

Prominent basal layer pigmentation similar to that Prominent basal layer pigmentation similar to that seen in lentigo simplex (hematoxylin-eosin stain, original magnification X200).

The number of melanocytes in these areas may be increased. Small nests of melanocytes are occasionally seen, and these are sometimes referred to as nevus incipiens. See the image below.

Elongated rete ridges and lentiginous proliferatio Elongated rete ridges and lentiginous proliferation of melanocytes at the dermal-epidermal junction (hematoxylin-eosin stain, original magnification X200).

Biopsy samples of the speckled regions show variable findings, including junctional lentiginous nevi, compound and intradermal nevi, as well as compound or intradermal nevi with congenital features.

See the images below.

Junctional melanocytic nevus composed of small nes Junctional melanocytic nevus composed of small nests of melanocytes and lentiginous melanocytic proliferation at the dermal-epidermal junction (hematoxylin-eosin stain, original magnification X100).
Compound melanocytic nevus with nests of uniform m Compound melanocytic nevus with nests of uniform melanocytes in the epidermis and the dermis (hematoxylin-eosin stain, original magnification X200).

Spitz nevi, blue nevi, and nevi with cytologic atypia (ie, dysplastic nevi) can also be seen. Collections of dermal melanophages without an inflammatory infiltrate are sometimes present.

 

Treatment

Medical Care

Photography and observation are the best clinical approaches for assessing the development of atypical features or the transformation to cutaneous melanoma.

Speckled lentiginous nevi are evaluated and treated with the same level of concern as would be warranted for congenital nevi of similar size. Atypical lesions should be examined with biopsy and histologic evaluation.

Surgical Care

Surgical removal is a therapeutic option for some patients. The entire area of hyperpigmentation must be excised to prevent recurrence because speckled lentiginous nevus represents a "field defect," ie, a defect in the melanoblasts that populate a localized area of the skin. Large scars can result.[21]

The Q-switched ruby or Q-switched Nd:YAG lasers have been used to treat both the background hyperpigmentation and the speckles of speckled lentiginous nevi. Results have not been promising from a cosmetic standpoint. Laser treatment of melanocytic nevi, including speckled lentiginous nevi, remains controversial.

Consultations

Consult a dermatologist when diagnostic and/or therapeutic uncertainty exists regarding melanocytic neoplasms in general and speckled lentiginous nevus specifically.