Page 719 - Textbook of Pathology, 6th Edition

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The Male Reproductive System
Chapter 23
Chapter 23
and Prostate

TESTIS AND EPIDIDYMIS at other sites along its descent from intra-abdominal location
to the scrotal sac.
NORMAL STRUCTURE ETIOLOGY. The exact etiology is not known in majority of
cases. However, a few apparent causes associated with
Contents of the scrotal sac include the testicle and epididymis
along with lower end of the spermatic cord and the tunica cryptorchidism are as under:
vaginalis that forms the outer serous investing layer. The 1. Mechanical factors e.g. short spermatic cord, narrow
epididymis is attached to body of the testis posteriorly. Thus, inguinal canal, adhesions to the peritoneum.
the testicle and epididymis may be regarded as one organ. 2. Genetic factors e.g. trisomy 13, maldevelopment of the
Structurally, the main components of the testicle are the scrotum or cremaster muscles.
seminiferous tubules which when uncoiled are of 3. Hormonal factors e.g. deficient androgenic secretions.
considerable length.
Histologically, the seminiferous tubules are formed of a MORPHOLOGIC FEATURES. Cryptorchidism is unila-
lamellar connective tissue membrane and contain several teral in 80% cases and bilateral in the rest.
layers of cells (Fig. 23.1,A). In the adult, the cells lining the Grossly, the cryptorchid testis is small in size, firm and
seminiferous tubules are of 2 types: fibrotic. CHAPTER 23
1. Spermatogonia or germ cells which produce spermatocytes Histologically, contrary to previous beliefs, the changes
(primary and secondary), spermatids and mature of atrophy begin to appear by about 2 years of age. These
spermatozoa. changes are as under (Fig. 23.1,B):
2. Sertoli cells which are larger and act as supportive cells 1. Seminiferous tubules: There is progressive loss of germ
to germ cells, produce mainly androgen (testosterone) and cell elements so that the tubules may be lined by only
little oestrogen. spermatogonia and spermatids but foci of
The seminiferous tubules drain into collecting ducts spermatogenesis are discernible in 10% of cases. The
which form the rete testis from where the secretions pass tubular basement membrane is thickened. Advanced
into the vasa efferentia. Vasa efferentia opens at the upper cases show hyalinised tubules with a few Sertoli cells only,
end of the epididymis. The lower end of the epididymis is surrounded by prominent basement membrane.
prolonged into a thick muscular tube, the vas deferens, that 2. Interstitial stroma: There is usually increase in the
transports the secretions into the urethra. interstitial fibrovascular stroma and conspicuous presence
The fibrovascular stroma present between the of Leydig cells, seen singly or in small clusters.
seminiferous tubules contains varying number of interstitial
cells of Leydig. Leydig cells have abundant cytoplasm CLINICAL FEATURES. As such, cryptorchidism is comp- The Male Reproductive System and Prostate
containing lipid granules and elongated Reinke’s crystals. letely asymptomatic and is discovered only on physical
These cells are the main source of testosterone and other examination. However, if surgical correction by orchiopexy
androgenic hormones in males. Thus, Sertoli and Leydig cells is not undertaken by about 2 years of age, or certainly in the
are hormone-producing cells homologous to their ovarian prepubertal period, significant adverse clinical outcome may
counterparts (granulosa-theca cells) and are termed specialised result as under:
stromal cells of the gonads. 1. Sterility-infertility. Bilateral cryptorchidism is associa-
Thus, the main functions of the testis are to produce ted with sterility while unilateral disease may result in
sperms and testosterone. infertility.
2. Inguinal hernia. A concomitant inguinal hernia is
CONGENITAL ANOMALIES frequently present along with cryptorchidism.
3. Malignancy. Cryptorchid testis is at 30-50 times increa-
Cryptorchidism
sed risk of developing testicular malignancy, most commonly
Cryptorchidism or undescended testis is a condition in which seminoma and embryonal carcinoma, than a normally
the testicle is arrested at some point along its descent. Its descended testis. The risk of malignancy is greater in intra-
incidence is about 0.2% in adult male population. In 70% of abdominal testis than in testis in the inguinal canal for the
cases, the undescended testis lies in the inguinal ring, in 25% simple reason that the neoplastic process in the testis in
in the abdomen and, in the remaining 5%, it may be present scrotal location is detected early than intra-abdominal site.