Penile cutaneous horn is a cone-shaped solid outgrowth of compacted keratin on the surface of the penis, which resembles a miniature horn. The size of the formation is variable: from a few millimeters to several centimeters. Keratin tumor is painless, unpleasant sensations, redness at the base and swelling can manifest during trauma or serve as signs of a cancerous process. Pathology is diagnosed by visual examination with dermatoscopy, for final verification, a biopsy with morphological examination is performed. Treatment of penile cutaneous horn involves surgical excision or various physical methods of destruction.
ICD 10
L85.8 N48.9
General information
The first mention of penile cutaneous horn is found in the works of the Danish anatomist Thomas Bartolin in 1670. The formation is preceded by the processes of hyperproliferation of skin cells. Synonyms: acrochordon, horny keratoma, fibrokeratoma Unna. Despite the fact that the protruding skin horn of the penis is a noticeable clinical sign, the genesis of pathology is most important. The growth of the cutaneous horn is initiated in 50% by benign processes, in 23-27% by actinic keratoses (precancerous) and in 20% by malignant tumors. Pathology is more common in light-skinned men in the age range from 60-70 years. Formations with malignant potential are detected at the age of 70 and older.
Causes
Sometimes the growth may appear without any visible prerequisites (primary acrochordon). Predisposing factors of secondary pathology are previous dermatological diseases: angiokeratoma, benign lichenoid keratosis, dermatofibroma, nevus, epidermolytic acanthoma, pseudoepitheliomatous balanitis, etc. Precancerous or malignant processes accompanied by hyperkeratosis in the form of a cutaneous horn include Bowen’s disease, keratoacanthoma, squamous cell carcinoma, basal cell carcinoma, melanoma, etc. The following are considered as the reasons triggering the growth of neoplasms:
- Traumatization. Injury to skin formations (papillomas, keratomas, warts) induces inflammation, which alters the process of cell growth and death. The body compensatorily tries to delimit the inflammatory process, as a result, the horn begins to form. There are cases when the growth began to develop after circumcision surgery performed for phimosis.
- Viral infection. Viral infections may be involved in the formation of the skin horn of the penis. The human papillomavirus, especially its subtypes 2, 16, 18, can contribute to the appearance of an excrescence with hyperkeratosis. Patients with papillomavirus infection and secondary cutaneous horn are more likely to develop squamous cell carcinoma of the penis. Infection with a contagious mollusk can also lead to hyperkeratosis.
- Ultraviolet irradiation. Men who have been treated with ultraviolet rays for psoriasis and the drug psoralen are more likely to encounter pathology. The risk group includes nudists who expose themselves to excessive insolation in direct sunlight.
- Endocrine disorders. In diabetes mellitus, metabolic processes are disrupted, as a result of which the skin loses moisture. Excessive dryness and the appearance of microcracks alter the protective functions of the epidermis. Balanoposthitis of fungal etiology often joins, which violates the integrity of the skin and provokes inflammation. Excessive dryness and microcracks contribute to the development of horny keratoma of the penis.
Pathogenesis
The pathogenesis of the cutaneous horn has not been fully studied. Probably, its development requires a combination of several alterating factors, including exogenous and endogenous, in combination with immunosuppression. Precancerous proliferation of the epidermis is initiated by accelerated mitosis, migration to the skin surface and apoptosis of cells containing keratin. Layered on top of each other, these cells gradually form an outgrowth. It can be based on any of the processes — cancer in situ, including Bowen’s, senile keratosis, keratoacanthoma, etc. Therefore, some clinicians in the field of dermatology are of the opinion that the “skin horn” is a preliminary diagnosis, and histological examination is necessary to determine the genesis.
Symptoms
Since pathology in most cases has no painful manifestations, the first signs of hyperkeratosis remain unnoticed. Initially, a small local thickening of the skin appears, which, as the basal cells multiply and become keratinized, begins to form into a curved, straight or twisted bone density growth of grayish or yellowish-brown color. Usually the height of the horn is twice as large as the width.
Symptoms of malignancy in malignant horny keratomas include the appearance of pain, an increase in size, redness, wrinkling or darkening of the skin around the base. The base itself can be wide, flattened or concave, while the adjacent tissues are hypertrophied or not changed. A large width compared to height is an alarming symptom, which indicates in favor of malignancy.
Complications
Since about 50% of skin growths are precancerous pathology, the main complication is the development of a malignant neoplasm. The cutaneous horn can interfere with sexual relations and disrupt the quality of life. Pressure on the growth is transmitted to the nerve endings, which causes pain. In case of injury, secondary inflammation may join at the base, which is accompanied by pain. Early access to a dermatologist allows you to avoid adverse consequences. In cases where the pathological process is based on a tumor, early diagnosis and timely therapy play a crucial role in the prognosis for life.
Diagnostics
A preliminary diagnosis is established on the basis of an examination. A small neoplasm without visible signs of malignancy can be assessed for malignancy after removal by providing samples of biomaterial to the pathology laboratory. In all doubtful cases , the examination algorithm is as follows:
- Dermatoscopy. The method provides a better visualization of education and allows you to consider the smallest details. Reddish edging, prevalence of width over height, crypts, increased vascular growth, ulceration are unfavorable signs that serve as indications for morphological examination.
- Biopsy with histology. Performing a biopsy before the intervention is crucial to exclude the oncological process and determine the management tactics. The histological picture is represented by hyperkeratosis, which can be orthokeratotic and parokeratotic in nature. Acanthosis of the granular layer of the epidermis with areas of randomly arranged cells is typical. Multiple mitoses indicate poor quality of education.
- MRI of the external genitalia. Magnetic resonance imaging may be useful for confirmed malignant nature of the horny keratoma. The study shows the depth of penetration or proximal expansion of the tumor, which affects the choice of therapeutic measures.
Treatment
A dermatologist is a doctor to whom most patients primarily turn. Penile cutaneous horn itself is easy to remove in a polyclinic, but it is important not to make a mistake with the cause of its occurrence. Therefore, it is preferable that the patient is necessarily consulted by an oncologist. Depending on the root cause, several options for the treatment of pathology are possible:
- Surgical removal. Extensive surgical excision is indicated with a confirmed malignant process accompanied by a horny keratoma, or if it is suspected. The operation is completed by cryofreezing the tumor bed. Wide excision allows to obtain a sufficient amount of material for morphology and eliminates the need for repeated surgical interventions. If the result shows squamous cell carcinoma, partial or complete penectomy is performed and, according to indications, chemotherapeutic treatment.
- Destruction by physical methods. Destruction with liquid nitrogen (cryodestruction), CO2/Nd-YAG laser coagulation and electrocoagulation can be used to remove skin horns that do not cause doubts about the goodness. The positive aspects include fewer scars and rapid recovery after treatment, but the effects change the structure of the tissue, which excludes morphological examination.
Prevention and prognosis
The prognosis for benign lesions is favorable, relapses after adequate surgical treatment are rare. In malignant processes accompanied by a cutaneous horn, the prognosis is serious and depends on the extent of the spread of the tumor, the timeliness of therapy, the immune status of the patient. Preventive measures imply the avoidance of STIs, excessive exposure to direct sunlight, the use of sunscreens, especially in persons with fair skin.