Nevi

Nevi are the third most common benign lesions encountered in the periocular region (after papillomas and epidermal inclusion cysts). They arise from nevus cells, which are grouped as clusters in the basal epidermis and dermis and in the junction zone between these 2 layers. Nevi are not apparent clinically at birth but begin to appear during childhood and often develop increased pigmentation during puberty.

Table 10-1 Melanocytic Skin Lesions of the Face

Figure 10-37 Compound nevus of the right lateral canthus.

(Courtesy of Cat N. Burkat, MD.)

Figure 10-38 Eyelid margin nevus.

Over the course of a lifetime, nevi evolve through 3 stages: (1) junctional (located in the basal layer of the epidermis at the dermal–epidermal junction), (2) compound (extending from the junctional zone up into the epidermis and down into the dermis), and (3) dermal (caused by involution of the epidermal component and persistence of the dermal component). In children, nevi arise initially as junctional nevi, which are typically flat, pigmented macules. Beyond the second decade, most nevi become compound, at which stage they appear as elevated, pigmented papules. Later in life, the pigmentation is lost, and the compound nevus remains as a minimally pigmented or amelanotic lesion (Fig 10-37). By age 70 years, virtually all nevi have become dermal nevi and have lost pigmentation.

Nevi are frequently found on the eyelid margin, characteristically molded to the ocular surface (Fig 10-38). Asymptomatic benign nevi require no treatment, but malignant transformation of a junctional or compound nevus can occur in rare cases. Nevi can also involve both the upper and lower eyelid margins (kissing nevus, Fig 10-39). Nevi may become symptomatic if they rub on the ocular surface or enlarge and obstruct vision or lacrimal outflow. When amelanotic, they can be confused with basal cell tumors (Fig 10-40). They are managed with shave excision or wedge resection.

Figure 10-39 Kissing nevus of the right upper and lower eyelids.

(Courtesy of Bobby S. Korn, MD, PhD.)

Figure 10-40 Amelanotic benign intradermal nevus of the right upper eyelid.

(Courtesy of Bobby S. Korn, MD, PhD.)

Ephelis (freckle)

An ephelis, or freckle, is a small, flat, brown spot that can occur on various areas of the body and facial skin, including malar areas, nose, and eyelids, or the conjunctiva. Ephelides arise from hyperpigmentation of the basal layer of the epidermis. Although the number of epidermal melanocytes is not increased, they extrude more than the usual amount of pigment into the epidermal basal cell layer. Ephelides are common in fair-skinned persons, and the hue of the ephelis darkens with sunlight exposure. No treatment is necessary other than sun protection.

Lentigo simplex

Simple lentigines are flat, pigmented spots that are larger in diameter than ephelides. Lentigo simplex can occur at any age and is not related to sun exposure. The condition also differs from ephelides in that the number of epidermal melanocytes is increased, and melanin is found in adjacent basal keratinocytes. Individual lesions are evenly pigmented and measure a few millimeters in diameter. Eyelid lentigines may be associated with Peutz-Jeghers syndrome (autosomal dominant polyposis of the intestinal tract). No treatment is necessary; however, melanin-bleaching topical agents may improve cosmesis.

Solar lentigo

Multiple solar lentigines may occur in older persons, in which case they are called senile lentigo (Fig 10-41). Chronic sun exposure produces pigmented macules with an increased number of melanocytes. Solar lentigines are uniformly hyperpigmented and somewhat larger than simple lentigines. The dorsum of the hands and the forehead are the most frequently affected areas. No treatment is necessary, but sun protection is recommended. Melanin-bleaching preparations, intense pulsed-light treatment, or cryotherapy may help fade the pigmentation of solar lentigines.

Figure 10-41 Solar lentigo of the left upper eyelid.

(Courtesy of Bobby S. Korn, MD, PhD.)

Figure 10-42 Right nevus of Ota.

(Courtesy of Cat N. Burkat, MD.)

Blue nevi

Blue nevi are dark blue-gray to blue-black, slightly elevated lesions that may be congenital or may develop during childhood. They arise from a localized proliferation of dermal melanocytes. The dark, dome-shaped lesions beneath the epidermis are usually 10 mm or less in diameter. Although their malignant potential is extremely low, these lesions are generally excised.

Dermal melanocytosis

Also known as nevus of Ota, this diffuse, congenital blue nevus of the periocular skin most often affects persons of African, Hispanic, or Asian descent, especially females. Dermal melanocytes proliferate in the region of the first and second dermatomes of cranial nerve V. The eyelid skin is diffusely brown, gray, or blue, and pigmentation may extend to the adjacent forehead (Fig 10-42). Approximately 5% of cases are bilateral. When patchy slate-gray pigmentation also appears on the episclera and uvea, as occurs in two-thirds of affected patients, the condition is known as oculodermal melanocytosis (Fig 10-43). Although malignant transformation may occur, especially in white patients, no prophylactic treatment is recommended. Approximately 0.25% of patients with oculodermal melanocytosis develop a uveal melanoma. Patients should also be monitored for glaucoma, as 10% of patients with oculodermal melanocytosis also have glaucoma and pigmentation of the trabecular meshwork.

Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.