ANOMALIES OF THE SPERMATIC CORD
Tumors of the paratesticular tissues and spermatic cord are rare and can occur in all age groups. More often, paratesticular tissues are involved by extension from primary germ cell testis tumors. Benign tumors are observed in two of three cases and are usually mesodermal in origin and include adenomatoid tumors, lipomas, fibromas, occasionally myomas from the cremasteric muscle, hemangiomas, neurofibromas, and lymphangiomas. Adenomatoid tumors are the most common benign tumors, accounting for 30% of all paratesticular tumors. They present as solid, asymptomatic masses found on routine examination and are located in the epididymis, testis tunic, or, rarely, the spermatic cord. On sectioning, they appear uniformly white, yellow, or tan and exhibit a fibrous consistency. Histologically, epithelial cells with vacuoles and uniformly sized, round nuclei are observed. Occasionally, adenomatoid tumors are misclassified as mesotheliomas. Dermoid cysts, the term given to cysts lined by squamous epithelium, are also rare causes of scrotal masses. Mesotheliomas of the testis adnexa usually present as firm, painless scrotal masses in association with an enlarging hydrocele (see Plate 3-9) in older individuals. Grossly, they are poorly demarcated lesions with firm, shaggy, and friable areas throughout. Microscopic examination reveals complex papillary structures and dense fibroconnective tissue containing scattered calcifications.
Malignant paratesticular tumors are also rare and include, in decreasing frequency, rhabdomyosarcoma (40%), leiomyosarcoma,
fibrosarcoma, liposarcoma, and undifferentiated tumors. Patients generally
present with a growing scrotal mass that is solid and non-transilluminating on
palpation. These tumors must be differentiated from spermatic cord cysts,
hydroceles, spermatoceles, varicoceles (see Plate 3-10), and hernias. Most
malignant tumors occur at the distal end of the cord near the scrotum, whereas
benign tumors are more often encountered proximally toward the inguinal canal.
Primary malignant tumors of the epididymis are exceedingly rare and mandate an
evaluation for meta-static adenocarcinoma. The treatment of benign lesions is
simple excision, whereas high inguinal orchiectomy, followed by radiotherapy
and chemotherapy, is standard treatment for malignant lesions.
Cystic fibrosis (CF) is the most common autosomal recessive disease in
Caucasians, with an incidence of 1:2500 births and a carrier frequency of 1:20.
The CF gene, called cystic fibrosis transmembrane regulator gene (CFTR; 7q31.2),
was cloned in 1989 and encodes the cyclic adenosine monophosphate–regulated
chloride channel found in many secretory epithelia. More than 1500 mutations
have been identified in the CFTR gene to date. Clinical features of CF include
chronic pulmonary obstruction and infection, exocrine pancreatic insufficiency,
neonatal meconium ileus, and male infertility. Indeed, more than 95% of affected
men have abnormalities in wolffian duct–derived structures manifesting most
commonly as congenital bilateral absence of the vas deferens (CBAVD).
Anatomically, the body and tail of the epididymis, vas deferens, seminal
vesicles, and ejaculatory ducts may be absent or atretic, but the testis
efferent ducts and caput epididymis (see Plate 3-3) are always present.
Interestingly, 1% to 2% of otherwise healthy, infertile men also have
CBAVD, which is considered a genital form of CF. These patients exhibit the
same spectrum of wolffian duct defects as those with CF but lack the severe
systemic problems. Spermatogenesis is normal in 90% of
men with CBAVD. It is thought that CBAVD is based on similar allelic patterns
as that observed in typical CF but it involves less-severe mutations. Isolated
CBAVD is considered an “atypical” form of CF and may be associated with subtle
lung disease, including chronic cough, sinusitis, and nasal polyps.
In addition to CFTR gene mutations, another genetic abnormality in CBAVD
patients is variation in the polythymidine tract of the splicing region of
intron 8 (IVS8), a noncoding DNA sequence within the CFTR gene. Three alleles
have been detected in this region: 5T, 7T, and 9T, and the efficiency of the
splice acceptor site function is greatest with the 9T allele. A reduction to 5T
decreases the efficiency of splicing, leading to a 10% to 50% reduction in CFTR
mRNA and a decrease in mature, functional CFTR
protein. It also appears that a coexisting 5T variant can turn an otherwise
phenotypically mild CFTR mutation into a severe one.
To complicate matters further, patients with congenital unilateral
absence of the vas deferens (CUAVD) are another male infertility phenotype that
is associated with CFTR mutations. Clinically similar to CBAVD patients,
affected men have a palpable vas deferens on one side. Despite this, many CUAVD
patients have azoospermia, suggesting the presence of additional, occult
wolffian duct abnormalities contralaterally. Wolffian duct anomalies that are
unrelated to CF gene mutations can also result in CBAVD. These patients have
associated ipsilateral renal hypoplasia or agenesis and generally do not
demonstrate CFTR mutations.
