Carcinoma of the penis overview

# Overview
Carcinoma of the penis is a malignant growth found on the skin or in the tissues of the penis. Carcinoma of the penis may be classified according to cell types into several subtypes: squamous cell carcinoma, adenocarcinoma, melanoma, basal cell carcinoma, lymphoma, and sarcoma. The incidence of carcinoma of the penis is approximately 1 per 100,000 men in the United States. On gross pathology, scaly patches or nodules, erythematous, and ulceration are characteristic findings of carcinoma of the penis. Common risk factors in the development of carcinoma of the penis are human papillomavirus, phimosis, poor genital hygiene, not being circumcised, weakened immune system, smoking, and treatment for psoriasis. And it is caused by an infection with human papillomavirus. The most common symptoms of carcinoma of the penis include non-healing lesion, change in the colour of the penis, redness or irritation of the penis, lump or thickening of the skin on the penis, phimosis, foul-smelling discharge or bleeding from the penis or from underneath the foreskin, itching or burning under the foreskin, swelling of the penis, lump in the groin, and dysuria. Biopsy is helpful in the diagnosis of carcinoma of the penis. The predominant therapy for carcinoma of the penis is surgical resection. Adjunctive chemotherapy, radiation therapy, and biological therapy may be required. Prognosis is generally good, and the 5-year survival rate of patients with carcinoma of the penis is approximately 67%.

# Classification
Carcinoma of the penis may be classified according to cell types into several subtypes including, squamous cell carcinoma, adenocarcinoma, melanoma, basal cell carcinoma, lymphoma, sarcoma.

# Pathophysiology
Most types of penile cancer traditionally begin as small lesions, most commonly on the glans or prepuce.  About 95% of penile cancers develop from flat, scale-like cells called squamous cells. squamous cell carcinoma (SCC) can develop anywhere on the penis, but most develop on the foreskin (in uncircumcised men) or the glans. This type of cancer is typically slow growing. When found early, it is often curable.  On gross pathology, the glans and the foreskin are the most common locations to find scaly patches, nodules, palpable painless lump, erythematous, ulceration, concurrent phimosis may conceal the lesion, surface of the lesion may be exophytic, flat, or ulcerated, chronic penile rash or subtle burning sensation and swollen inguinal lymph nodes as characteristic findings of carcinoma of penis.  On microscopic histopathological analysis, keratinization and intercellular bridges are characteristic findings of carcinoma of the penis. Penile cancer arises from precursor lesions, which generally progress from low-grade to high-grade lesions.

# Epidemiology and Demographics
The incidence of carcinoma of the penis is approximately 1 per 100,000 males in the United States. The majority of cases are reported in less developed areas. The incidence of penile cancer increases with age; the diagnostic median age usually is 40 - 70 years, median age 58 years.  Penile cancer is rare if circumcision is done at birth, and is more common in cases of late circumcision (after age 10).  Carcinoma of the penis is more prevalent in populations with lower education and higher poverty.  More commonly seen in Hispanic and African American men; familial cases have occasionally been reported.

# Risk Factors
Common risk factors in the development of carcinoma of the penis include human papillomavirus,  phimosis, poor genital hygiene, uncircumcised males, weakened immune system, smoking, and psoralen ultraviolet A (PUVA) therapy treatment for psoriasis.

# Screening
According to the the U.S. Preventive Service Task Force (USPSTF), there is insufficient evidence to recommend routine screening for carcinoma of the penis.

# Causes
Carcinoma of the penis is caused by an infection with human papillomavirus.

# Differential Diagnosis
Carcinoma of the penis must be differentiated from condyloma acuminata, penile intraepithelial neoplasia (PeIN), balanitis xerotica obliterans, Buschke-Lowenstein tumour, Bowenoid papulosis, leukoplakia.

# Prognosis
Prognosis of carcinoma of the penis is generally good, and the 5-year survival rate is approximately 67%. The prognosis varies with the stage of tumor; stages 0II have the most favorable prognosis.

# Staging
Carcinoma of the penis may be classified into several subtypes based on TNM system and UICC staging system.

# History and Symptoms
The most common symptoms of carcinoma of the penis include any non-healing lesion, change in the colour of the penis, redness, irritation of the penis, lump, thickening of the skin on the penis, phimosis, foul-smelling discharge, bleeding from the penis or from underneath the foreskin.

# Physical Examination
Common physical examination findings of carcinoma of the penis include weight loss, pallor, inguinal lymphadenopathy, non-healing ulcer on the penis,  mass on the penis, phimosis, skin induration on the penis, change in the colour of the penis, erythema of the penis, foul-smelling discharge, bleeding from the penis or from underneath the foreskin, as well as swelling of the penis.

# Laboratory Tests
Some patients with carcinoma of the penis may have elevated concentration of serum calcium, which is usually suggestive of bone metastases.

# X Ray
There are no X-ray findings associated with carcinoma of the penis. X-ray may be performed to detect metastases of penile cancer to lungs and bones.

# CT
CT scan may be performed to detect metastases of carcinoma of the penis to surrounding lymph nodes, liver, lungs, and other organs.

# MRI
MRI may be performed to detect metastases of carcinoma of the penis to brain, spinal cord, and nearby organs and tissues.

# Ultrasound
Ultrasound may be helpful in the diagnosis of the extent of carcinoma of the penis.

# Other Imaging Findings
There are no other imaging findings associated with carcinoma of the penis.

# Other Diagnostic Studies
There are no other diagnostic study findings associated with carcinoma of the penis.

# Biopsy
Biopsy is helpful in the diagnosis of carcinoma of the penis.

# Medical Therapy
The predominant therapy for carcinoma of the penis is surgical resection. Adjunctive chemotherapy, radiation therapy, and biological therapy may be required.

# Surgery
Surgery is the mainstay of treatment for carcinoma of the penis.

# Primary Prevention
Effective measures for the primary prevention of carcinoma of the penis include circumcision, good personal hygiene, and safer sexual practices. Gardasil vaccine is recommended for men to prevent HPV infection.

# Secondary Prevention
There are no secondary preventive measures available for carcinoma of the penis.