Testicular conditions
Testicular microlithiasis and cryptorchidism have both been associated
with increased risk of testicular cancer, which is in line with the
highly suggestive evidence stemming from the present study. The majority
of preadolescent boys with testicular microlithiasis and cancer have
other predisposing conditions, such as cryptorchidism. Testicular
microlithiasis is a relatively uncommon condition characterized by the
presence of calcifications in the testicular parenchyma, possibly due to
dysgenesis of the testis with slough of degenerated cells inside an
obstructed seminiferous tubule. The mechanisms that may explain how
these calcifications may be involved in the pathogenesis of testicular
cancer remain unclear; in particular, it is far less known whether and
when a patient with microlithiasis would develop testicular cancer. It
is also possible that testicular microlithiasis may be associated with
rather than being a risk for future development of testicular tumor,
because the follow-up of patients with incidental microlithiasis have
shown a low risk of developing testicular cancer. Despite this debate,
our results are in line with previous studies supporting the general
recommendations of regular screening for testicular cancer in case of
testicular microlithiasis. Although the association between
cryptorchidism and testicular cancer has been well-studied, the
underlying mechanisms remain poorly understood. Cryptorchidism is one of
the strongest risk factors for infertility and testicular germ cell
tumors. Although corrective surgery largely reduces the risk of this
tumor, in some cases the affected testis becomes cancerous. This finding
is suggestive of permanent epigenetic changes as differences in promoter
methylations and corresponding gene expression of several genes have
been reported in testicular germ cell tumors. Gene expression in
cryptorchid testes and animal models has shown deregulation of growth
factors important for the balance of self-renewal and the proliferation
of germ cells . The open question is whether the risk of malignant
malformation is the result of a genetic predisposition or is due to the
maldescent testis, which is more prone to dysplasia and malformation. In
cases of isolated cryptorchidism, the 10% increased risk of developing
cancer in the contralateral normally descended testis has provided
indications that genetic factors may also play significant role by
inducing aberrant gonadocyte development in fetal life.