BENIGN EPITHELIAL TUMORS

PAPILLOMA

A papilloma is the upward proliferation of skin resulting in an elevated irregular lesion. It may occur as a sessile tumor of the lid margin, or a pedunculated lesion (skin tag) (131–137). The tumor consists of fingerlike processes of a vascularized debris which is covered with a hyperplastic squamous epithelium. The epithelium is usually acanthotic, keratotic, and hyperkeratotic. Other lesions such as actinic keratosis, verruca vulgaris, and seborrheic keratosis may have papillomatous-like formations.

131

131 Fibroepithelial papilloma of the right upper lid and skin.

SEBORRHEIC KERATOSIS (BASAL CELL PAPILLOMA, SEBORRHEIC WART, SENILE VERRUCA)

Seborrheic keratosis is one of the most frequently observed skin lesions occurring on the lids. It is a superficial brown/black lesion which is well circumscribed and slightly elevated. The lesion has no extensions into the dermis, and there is usually no surrounding inflammation. If it does become inflamed, it may be mistaken for a basal cell or squamous cell carcinoma (138–141).2

INVERTED FOLLICULAR KERATOSIS

(BASOSQUAMOUS CELL EPIDERMAL

TUMOR, BASOSQUAMOUS CELL ACANTHOMA, IRRITATED SEBORRHEIC KERATOSIS)

Inverted follicular keratosis has a predilection for the face and is often confused with carcinoma by both the clinician and the pathologist. It usually presents as a single papillary or marginal projection from the skin surface. There may be an inverted configuration resembling molluscum contagiosum or keratoacanthoma.

In a clinicopathological study, the authors reported that most inverted follicular keratoses occurred on the lid margins of men with an age range of 17–74 years. The lesions, which usually were solitary, had varied clinical presentations that were described as nodular, papillary, papillomatous, or verrucous. The greatest diameter of the tumors was usually <5 mm (0.2 in). The authors suggested that inverted follicular keratosis might be of viral origin.13

PRECANCEROUS EPITHELIAL TUMORS

ACTINIC KERATOSIS (SOLAR KERATOSIS)

Actinic keratoses usually occur on areas exposed to the sun in fair-skinned people. They often occur as multiple lesions which may be flat and scaly, papillomatous, or projecting as a horn (cutaneous horn) (142–144). Cutaneous horn is a descriptive clinical term with many underlying causes. Solar keratosis, verruca vulgaris, seborrheic keratosis, inverted follicular keratosis, squamous cell carcinoma (19), and even sebaceous gland carcinoma can present as cutaneous horns.

Solar keratosis can transform to squamous cell carcinoma. Considering its predisposition to carcinoma, the appropriate treatment is complete surgical excision.

142

142 Actinic keratosis in the form of a cutaneous horn in the left medial canthal area.

143 Typical appearance of a cutaneous horn with a long thin projection of keratin (the horn).

144 Hyperkeratotic actinic keratosis in the center of the right lower lid. (The lesion appears similar to the seborrheic keratosis in 139.)

Precancerous Epithelial Tumors 49

DYSPLASIA

Dysplasia of the conjunctival epithelium may appear as leukoplakia, which is a clinical descriptive term referring to a white plaque. Leukoplakia may occur on the conjunctival side of the eyelid. The white, shiny appearance is due to keratinization of the normally nonkeratinized conjunctival epithelium. Precancerous dysplasia may appear as leukoplakia, but so may squamous cell carcinoma, carcinoma in situ, and even pingueculae (64, 65).

A biopsy is necessary to determine the cause of the leukoplakia. If a precancerous dysplasia exists, surgical treatment is usually efficacious in eliminating the condition. However, radiation therapy and cryotherapy may also be effective in some cases.

143

144

SEBACEOUS GLAND TUMORS

Congenital sebaceous gland hyperplasia (nevus sebaceous Jadassohn, congenital sebaceous gland hamartoma)

Congenital sebaceous gland hyperplasia consists of a single hairless plaque which usually reaches its final size at puberty. The tumor seems to be caused by a developmental error resulting in localized hyperplasia of sebaceous glands, often associated with imperfectly developed hair follicles and, occasionally, glands.8 This tumor is considered a hamartoma,2 a congenital tumor composed of tissues that are normally found in the involved area. Nevus sebaceous may be complicated by the presence of other tumors such as basal cell epithelioma, squamous cell epithelioma, syringocystoadenoma papilliforum, and keratoacanthoma.14

Sebaceous adenoma

Sebaceous adenoma is a rare benign tumor that can appear on the eyebrow and eyelid. It appears as a single, firm, yellowish nodule. Histologically, these tumors may be composed of mature transitional and mature sebaceous cells.15 This tumor can resemble a sebaceous gland carcinoma.

A biopsy of this tumor should be taken to confirm the diagnosis. The tumor can then be removed for cosmetic or functional reasons.

TUMORS OF HAIR FOLLICLES Trichoepithelioma

Trichoepitheliomas can occur as a single nodule or as a few isolated nodules. The nodule is small, rosy-yellow, or fleshcolored, and tends to grow to several millimeters or, occasionally, to a centimeter (13). The characteristic finding histologically is multiple horn cysts which consist of a completely keratinized center surrounded by basal cells. These basal cells are indistinguishable from the cells that constitute basal cell carcinoma. The cyst may rupture and induce a granulomatous foreign body giant cell reaction, or it may become calcified. A hereditary type of trichoepithelioma which is cystic and multiple is referred to as Brooke’s tumor.8, 11

Calcifying epithelioma of Malherbe (pilomatrixoma)

The calcifying epithelioma of Malherbe may arise in the eyelid or brow and usually occurs in children or young adults. The nodule, which arises from cells of a hair follicle, is pink to reddish purple with subepithelial patches of yellow, and its consistency ranges from firm to cystic. The growth rate is moderate, the average size of <10 mm (0.4 in) being reached within weeks or months. There is usually intact overlying skin with telangiectatic vessels. These tumors rarely recur after surgical excision.16, 17

Trichofolliculoma and trichilemmoma

Trichofolliculoma and trichilemmoma are rare benign tumors of hair follicles. These lesions tend to be solitary, small, and asymptomatic, and occur in middle-aged or elderly people.15

145 Syringoma in the area of the punctum in the right lower lid.

SWEAT GLAND TUMORS

Eccrine sweat glands are present at the lid margin and in the dermis over the surface of the eyelid. Apocrine sweat glands in the eyelids are referred to as the glands of Moll.

Syringoma

Syringoma is a relatively common tumor arising from an eccrine sweat structure. It consists of a small, soft papule measuring 1–2 mm (0.1 in). The lesions, which occur primarily on the eyelids, may be multiple and resemble milia (145, 146).11

Eccrine spiradenoma (nodular hidradenoma, clear cell hidradenoma, clear cell myoepithelioma)

These adenomas usually occur as deep single dermal nodules arising from eccrine structures (147). A variant of this tumor is the eccrine hidrocystoma (148–151). This tumor can arise in the dermis and grow to a diameter of 10 mm (0.4 in) or more. The tumor may project into the orbital tissues and present as an orbital mass (148–150).

Another rare type of sweat gland tumor is the cylindroma, which is probably of apocrine origin and is almost always benign. The tumors are often multiple, smooth, firm, pinktoned in color, and sometimes pedunculated.15

Syringocystadenoma papilliferum

Syringocystadenoma papilliferum is a benign tumor of the skin thought to be of apocrine origin.18 The lesion usually occurs in the scalp as a hairless, smooth plaque until puberty, after which it becomes raised, nodular, and verrucous.

This tumor is rarely found on the eyelids. However, two cases were reported in which the adenoma was present on the lid margins of men in their early thirties. One of the tumors was hyperkeratotic; the other was cystic in appearance. Both lesions had slow and quiet onsets, and there was no history of excessive sun exposure. It is of interest that the initial biopsies of one of these tumors was read as basal cell carcinoma. This type of pathological misdiagnosis has been known to occur when dealing with unusual or unsuspected eyelid margin tumors.18

148–151 Eccrine hidrocystoma. 148: Eccrine hidrocystoma surgically removed from the orbit of a 30-year-old male who felt a soft mass in his right upper lid. 149: Computed axial tomogram showing anterior orbital lesion. (Same patient as in 148.) 150: B-scan ultrasonogram showing lack of reflectivity in the oval space divided by the straight line.This anechoic area indicates that the mass seen in the tomogram of 149 is a cystic structure.

151 Hidrocystoma just beneath the punctum of the left lower lid.This is the more typical appearance of this type of cyst. Care must be taken to avoid the canaliculus when surgically removing the cyst.