Page 34 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 2-7 Integumentary System

EPHELIDES

EPHELIDES AND LENTIGINES

Ephelides, also known as freckles, are common benign
findings. They typically manifest in childhood in fair-
skinned individuals, especially those with red or blonde
hair color. Ephelides tend to be passed down from
generation to generation in an autosomal dominant
inheritance pattern.
Lentigines are sun-induced proliferations of melano-
cytes. They tend to occur in older people, but they may
be seen in individuals at a young age after repetitive Ephelides, also known as freckles, are most
sun exposure. They can be almost impossible to dif- frequently encountered in fair-skinned
ferentiate from ephelides. Solar lentigines have many individuals on sun-exposed skin. Sun
synonyms, including sun spots, liver spots, and lentigo exposure causes accentuation.
senilis.
Clinical Findings: Ephelides occur at a very young
age and tend to show an autosomal dominant inheri-
tance pattern. They are accentuated in sun-exposed
regions, particularly the head, neck, and forearms.
Exposure to the sun or other ultraviolet source causes
the ephelides to become darker and clinically more
noticeable. They do not occur within the oral mucosa.
They are usually uniform in coloration but can have
many different sizes and shapes. Some are round or
oval; others are angulated or have a bizarre shape. Their
color is usually a uniform light to dark brown; they are
never black. They have no malignant potential. Patients
with multiple ephelides may have a higher risk for
skin cancer, because their presence may be an indication
of increased exposure to ultraviolet radiation. The dif-
ferential diagnosis is usually very narrow and includes
lentigines and common acquired nevi. The clinical
location, age at onset, family history, and skin type
usually make the diagnosis straightforward. The diffi-
culty can occur when trying to differentiate a solitary
lentigo from an ephelide in an adult patient.
Solar lentigines most often arise in the adult popula-
tion and are distributed evenly among males and
females. They can occur in anyone but are much more Low power. Basilar pigmentation is uniformly seen along the biopsy specimen. There is no increase in
common in light-skinned persons. The number of len- the density of melanocytes present.
tigines typically increases with the age of the patient.
Lentigines are induced by ultraviolet radiation, the
most common source being chronic sun exposure. Len-
tigines tend to get darker with ultraviolet light exposure
and lighten over time when removed from the expo-
sure. Unlike ephelides, they never completely fade
away. They are clinically highly uniform in color and
size within an individual patient. They can be small
(1-5 mm), but some are much larger (2-3 cm in diam- High power. Pigmentation is isolated to the basal
eter). They are most commonly located in sun-exposed layer. A nice basketweave stratum corneum is
areas but in some syndromes can be located anywhere seen with a nicely formed granular layer.
on the human body, including the mucosal regions.
Over time, some lentigines merge together to form
rather large lentigines.
There are some important variants of lentigines.
Lentigo simplex and the ink spot lentigo are two very
common versions. Lentigo simplex is believed to occur
at any age and to have no or minimal relationship to
sun exposure. The lesions are found anywhere on the
body. Ink spot lentigines are variants of lentigo simplex One of the more important and unique variants of of patients who have undergone prolonged PUVA
that are differentiated by their characteristic dark lentigines are the psoralen + ultraviolet A light (PUVA) treatment will develop PUVA lentigines. They are
brown to almost black coloration. Under dermato- lentigines. PUVA lentigines are iatrogenic in nature more common in patients with fair skin types and rarely
scopic evaluation, they have a characteristic uniform and occur after medical therapy with PUVA treatment. occur in darker-skinned individuals. The lentigines
pigment network, with accentuation of pigment in the Patients who have undergone long-term therapy with induced by PUVA therapy are permanent and can have
rete ridge regions. They are so named because they PUVA have a high risk of developing PUVA lentigines. disastrous cosmetic consequences. Like all patients
have the appearance of a tiny drop of dark ink dropped These lentigines are darkly pigmented macules that undergoing ultraviolet phototherapy, these patients
on the skin. Neither of these two forms of lentigines occur across the entire body except in the areas that must be routinely monitored for their entire lives,
has malignant potential. were not exposed to the PUVA therapy. More than half because they are at increased risk for melanoma and

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