A Spitz nevus is a

benign Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malign ...

skin lesion A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this s ...

. A type of

melanocytic nevus A melanocytic nevus (also known as nevocytic nevus, nevus-cell nevus and commonly as a mole) is a type of melanocytic tumor that contains nevus cells. Some sources equate the term mole with "melanocytic nevus", but there are also sources that equat ...

, it affects the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

and

dermis The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided i ...

.LeBoit, PE, Burg G, Weedon D, Sarasin A. (Eds) World Health Organization Classification of Tumours: Pathology and Genetics of Skin Tumours. Lyon: ''IARC''Press. 2006. It is also known as an epithelioid and spindle-cell nevus, and misleadingly as a benign juvenile melanoma, and Spitz's juvenile melanoma). The name ''juvenile melanoma'' is generally no longer used as it is neither a melanoma, nor does it occur only in children.Crotty, K. Spitz Naevus: Histological features and distinction from malignant melanoma. Australasian Journal of Dermatology. 38 (suppl): S49-S53. 1997.

Pathophysiology

The cause of Spitz nevi is not yet known. There is an association with

sunburn Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, usually from the Sun. Common symptoms in humans and animals include: red or reddish skin that is ho ...

, but causation is not established. Genetic studies of Spitz nevi have shown that most cells have the normal number of

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

s, however a minority (25%) of cells have been shown to contain extra copies of parts of some chromosomes, such as the short arm of

chromosome 11 Chromosome 11 is one of the 23 pairs of chromosomes in humans. Humans normally have two copies of this chromosome. Chromosome 11 spans about 135 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the tot ...

(11p).

Diagnosis

Pie chart of incidence and malignancy of pigmented skin lesions

histopathology Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία '' -logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Spe ...

, Spitz nevi characteristically have vertically arranged nests of nevus cells that have both a spindled and an epithelioid morphology.

Apoptotic Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes includ ...

cells may be seen at the

dermoepidermal junction The dermoepidermal junction or dermal-epidermal junction (DEJ) is the area of tissue that joins the epidermal and the dermal layers of the skin. The basal cells in the stratum basale of the epidermis connect to the basement membrane by the anchori ...

. The main

histologic Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

differential diagnoses In healthcare, a differential diagnosis (abbreviated DDx) is a method of analysis of a patient's history and physical examination to arrive at the correct diagnosis. It involves distinguishing a particular disease or condition from others that p ...

are

pigmented spindle cell nevus A pigmented spindle cell nevus is a skin condition characterized by a dark brown to black macule or papule, usually less than 6 mm. It was characterized in 1975. See also * Partial unilateral lentiginosis * List of cutaneous conditions * ...

and

malignant melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the Biological pigment, pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, i ...

Treatment

Surgical removal is usually performed, even though it is benign.

Epidemiology

Spitz nevi are uncommon. Their annual incidence was estimated in a coastal population of

sub-tropical The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north and ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

to be 1.4 cases per 100,000 people. For comparison, the annual incidence of

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

in the same population, which is high by world standardsRies LAG, et al., eds. SEER Cancer Statistics Review, 1975–2000. Bethesda, MD: National Cancer Institute; 2003: Tables XVI-1-9. is 25.4 cases per 100,000 people. Although they are most commonly found on people in their first two decades of life, the age range for people with Spitz nevi is from 6 months to 71 years, with a

mean There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value (magnitude and sign) of a given data set. For a data set, the ''arithme ...

age of 22 years and a

median In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...

age of 19 years.

Eponym

The lesion is named after

Sophie Spitz Sophie Spitz (4 February 1910 – 11 August 1956) was an American pathologist who published the first case series of "juvenile melanoma," (a special form of benign melanocytic nevi), skin lesions that have come to be known as Spitz nevi.Crotty, ...

, the pathologist who originally described it in 1948.Spitz S. Melanomas of childhood. Am. J. Pathol.1948;24:591-609.

References

External links

{{Skin tumors, nevi and melanomas Melanocytic nevi and neoplasms Rare diseases