Squamouscellcarcinomaanditsprecursorlesionsarethemostimportantpenilelesions.ManyareassociatedwithHPVinfection.
Squamouscellcarcinomaoccursontheglansorshaftofthepenisasanulceratedinfiltrativelesionthatmayspreadtoinguinalnodesandinfrequentlytodistantsites.Mostcasesoccurinuncircumcisedmales.
Otherimportantpeniledisordersincludecongenitalabnormalitiesinvolvingthepositionoftheurethra(epispadias,hypospadias)andinflammatorydisorders(balanitis,phimosis).
Fig. 18.2 Carcinomaofthepenis.Theglanspenisisdeformedbyanulcer-ated,infiltrativemass.
SCROTUM,TESTIS,ANDEPIDIDYMIS
Several inflammatory processes may affect the skin of the scrotum, including local fungal infections and systemic dermatoses, such as psoriasis (Chapter 24). Neoplasms of the scrotal sac are unusual. Squamous cell carcinoma, the most common of these, is of historical interest in that it represents the first human malignancy associated with environmental exposures, dating from Sir Percival Pott’s observation of a high incidence of the disease in chimney sweeps. The subsequent edict by the Chimney Sweeps Guild that its members must bathe daily remains one of the most successful public health measures for cancer prevention. Several disorders unrelated to the testes and epididymis may present as scrotal enlargement. Hydrocele, the most common cause of scrotal swelling, is caused by an accumulation of serous fluid within the tunica vaginalis. It may be idiopathic or arise in response to neighboring infections or tumors. The clear fluid of a hydrocele allows light to pass through (transluminescence), distinguishing it from collections of blood, pus, or lymph, all of which are cloudy or opaque. Accumulation of blood or lymphatic fluid within the tunica vaginalis, termed hematocele and chylocele, respectively, also may cause scrotal enlargement. In extreme cases of lymphatic obstruction, caused, for example, by filariasis, the scrotum and the lower extremities may enlarge to grotesque sizes—a condition termed elephantiasis.
Cryptorchidism is a failure of testicular descent into the scrotum. Normally, the testes descend from the abdominal cavity into the pelvis by the third month of gestation and then through the inguinal canals into the scrotum during the last 2 months of intrauterine life. The diagnosis of cryptorchidism is only established with certainty after 1 year of age, particularly in premature infants, because testicular descent into the scrotum is not always complete at birth. Cryptorchidism affects 1% of the male population. In the vast majority of cases, the cause is unknown. The condition is bilateral in approximately 10% of affected patients, a small percentage of whom have chromosomal aberrations and other developmental abnormalities. Because undescended testes become atrophic, bilateral cryptorchidism results in sterility. For unclear reasons, even unilateral cryptorchidism may be associated with atrophy of the contralateral descended gonad.
In addition to infertility, failure of testicular descent is associated with a 3to 5-fold increased risk for testicular cancer. Patients with unilateral cryptorchidism also are at increased risk for the development of cancer in the contralateral, normally descended testis, suggesting that some intrinsic abnormality, rather than simple failure of descent, underlies the increased cancer risk. Surgical placement of the undescended testis into the scrotum (orchiopexy) is recommended by 18 months of age to decrease the likelihood of testicular atrophy, infertility, and testicular cancer.