Dermatological Disease of the Penis

(1)

Pediatric Surgery, Al Azher University, Cairo, Egypt

Abstract

Various wide range of dermatological diseases may affect the skin of the penis and prepuce. Some are unique to the genitalia, so they are genitally specific like; penile freckles, lentigo and juvenile xanthogranuloma (JXG). Other more common dermatoses which may have a unique appearance when they involve genital skin and mucosa like; psoriasis, lichen planus, and seborrheic dermatitis, some infectious dermatological diseases are affecting the penis before they affect other areas; like herpes, and gonorrhoea. A wide range of infectious, neoplastic, immunological and inflammatory dermatoses can affect the penis, but only nonmalignant skin lesions, which may had a congenital background in their aetiology and carry some significance for the pediatric surgeons and urologists will be discussed; other skin lesions that may affect genital skin as well as the skin of any part of the body are beyond the scope of this chapter.

Keywords

AngiomyofibroblastomaAngiokeratomasPenile melanosisPenile frecklesPenile lentigoJuvenile xanthogranulomaPigmented nevusDivided nevusCongenital melanocytic nevi

Dermatologica l lesions of surgical importance include:

Angiomyofibroblastoma.
Angiokeratomas
Penile hyperpigmentation.
- Penile melanosis.
- Penile freckles.
- Penile lentigo.
Penile hypopigmentation.
Yellow pigmented lesion: juvenile xanthogranuloma (JXG)
Balanitis, balanoposthitis: are discussed before in Chap. 39.
Haemangioma (Chap. 17)

40.1 Angiomyofibroblastoma

It is a benign, rare mesenchymal tumor arising from the genital tract of both men and women and was recently described for the first time by Fletcher et al. in 1992 [2].

Nomenclature

Male angiomyofibroblastoma-like tumor and cellular angiofibroma

Definition

Rare benign oedematous tumor of perineum and external genitalia, it may arise from penis, scrotum, inguinal region, and in female it arise from the vulva, as a well-circumscribed, with soft to rubbery cut surface and somewhat oedematous appearance, with variable size. It had a low tendency for recurrence. It appears as solid cystic masses on ultrasound images, which is the most valuable tool to establish a preoperative diagnosis of this tumor entity [3].

40.1.1 Histological features

Hypercellular areas located around vascular spaces of spindle, plump or oval stromal cells that alternate with hypocellular areas containing similar cells loosely dispersed in an edematous background.

40.1.2 Differential diagnosis

This tumor needs to be distinguished from other, similar lesions, such as hemangioma, deep and superficial aggressive angiomyxoma and cellular angiofibroma, because aggressive angiomyxoma demands much more extensive treatment.

40.1.3 Treatment

Simple excision

40.2 Angiokeratomas: (Angiokeratoma of Fordyce)

Incidence

The prevalence of angiokeratomas is unknown, but is believed to be less than 1 %. These lesions occur more often in men than women, and are more common in white persons.

Definition

Angiokeratomas are benign, well-circumscribed, red or blue papules measuring 1–6 mm that typically occur in patients older than 40 years [4]. Patients tend to present with multiple lesions, although solitary lesions are not uncommon, with greater numbers with increasing age, older lesions are larger and more keratotic.

The diagnosis is usually made by characteristic appearance, although it may be misdiagnosed as penile cancer or pearly papules. Angiokeratomas may affect only the glans penis, and the patients may experience rare intermittent bleeding, pain, or pruritus.

This angiokeratomas should be distinguished from angiokeratoma of Fabry (a rare genetic metabolic disorder secondary to alpha-galactosidase deficiency and impaired glycosphingolipid metabolism).

Treatment is indicated if the patient is symptomatic or if the lesions bleed. Options include surgery, cryoablation, electrocautery, and hyfrecation or vascular laser ablation. Treatment may be difficult in patients with extensive lesions.

40.3 Hyperpigmented Genitalia

Definition

Localized or generalized increased genital pigmentation.

Hyperpigmentation can affect other parts of the body or be restricted to the genitalia, and the localized areas of hyperpigmentation of the glans of the penis are especially common. This should be differentiated from Freckled genitalia in which one or more small, focal areas of hyperpigmentation are present. Localized hyperpigmentation can be objectively determined due to the difference from the immediate surrounding tissue colour, while generalized hyperpigmentation may be more difficult to determine and is therefore a subjective manifestation. If the finding is localized, the description should be appended with a description of the affected part(s).

40.4 Penile Melanosis

The most common cause of dark spot on penis is penile melanosis.

Definition

Penile melanosis is well-defined, oval, brown to black, flat patch that can be seen on glans penis, prepuce or shaft of penis. Sometimes they may have irregular border and change in colour that can cause confusion with scary and malignant lesion like melanoma. In most cases biopsy is indicated (Fig. 40.1).