Saturday, March 13, 2021

Testicular Cancer Case File

Posted By: Medical Group - 3/13/2021 Post Author : Medical Group Post Date : Saturday, March 13, 2021 Post Time : 3/13/2021
Testicular Cancer Case File
Eugene C. Toy, MD, Lawrence M. Ross, MD, PhD, Han Zhang, MD, Cristo Papasakelariou, MD, FACOG

CASE 28
A 20-year-old male reports that he has had a nontender, heavy sensation in his scrotal area for 2 months. He jogs several miles every day but denies lifting heavy objects. He does not recall trauma to the area, has no urinary complaints, does not smoke, and otherwise appears healthy. His blood pressure is 110/70 mmHg, his heart rate is 80 beats/min, and he is afebrile. Heart and lungs examinations are normal. His back and abdomen are nontender, and no abdominal masses are detected. External genitalia examination reveals a 2-cm nontender mass in the right testicle that shows no light penetration with transillumination. The rectal examination is unremarkable.

⯈ What is the most likely diagnosis?


ANSWER TO CASE 28:

Testicular Cancer
Summary: A 20-year-old male is noted to have a nontender heavy sensation in the scrotal area of 2 months’ duration. He jogs several miles each day and denies lifting heavy objects, scrotal trauma, and urinary problems. A 2-cm, nontender, nontransilluminating mass is noted in the right testicle. The rectal examination is unremarkable.

• Most likely diagnosis: Testicular cancer


CLINICAL CORRELATION
Testicular carcinoma affects young men, usually between ages 15 and 40 years, and the presence of a painless scrotal mass is the most common presentation. A history of trivial scrotal trauma is not uncommon, which often brings the scrotal mass to the patient’s attention. Testicular carcinoma should be ruled out before other conditions are considered, such as varicocele, spermatocele, hydrocele, epididymitis, or testicular torsion. Regular scrotal examination is advocated but rarely performed, and personal embarrassment often delays medical consultation.


APPROACH TO:
Male Genitalia

OBJECTIVES
1. Be able to describe the anatomy of the external male genitalia
2. Be able to draw the blood supply and lymphatic drainage of the testicles

DEFINITIONS
TRANSILLUMINATION: Passage of light through a specific tissue during examination with the object between the light source and the examiner

CIRCUMCISION: Removal of all or part of the prepuce or foreskin

HYDROCELE: Collection of fluid in the tunica vaginalis of the testicle or along the spermatic cord


DISCUSSION
The male external genitalia consist of the penis and the scrotum, which contains the testes, the male gonad. All of these structures lie within the boundaries of the urogenital triangle of the perineum. The relations of the perineal fascia and spaces (pouches) of the male perineum are similar to those described for the female perineum (see Case 27). For example, the membranous layer of the superficial fascia
Ventral view of the penis

Figure 28-1. Ventral view of the penis. (Reproduced, with permission, from Lindner HH. Clinical Anatomy. East Norwalk, CT: Appleton & Lange, 1989:498.)

attaches to the posterior margin of the perineal membrane, the same three superficial perineal muscles are surrounded by the deep perineal fascia, and superficial and deep spaces are present. However, in the male perineum, the fatty layer of the superficial fascia is virtually absent on the penis and is replaced by smooth (dartos) muscles in the scrotum. The membranous layer of the superficial fascia is continuous in the penis and scrotum as the dartos fascia (Figures 28-1 and 28-2).

The penis is developmentally homologous to the clitoris in the female and has many anatomical similarities. However, the urethra traverses the corpus spongiosum.

Testicular Cancer anatomy

Figure 28-2. Transverse section of the penis. (Reproduced, with permission, from Lindner HH. Clinical Anatomy. East Norwalk, CT: Appleton & Lange, 1989:500.)

The penis consists of root, body, and glans, which are formed from three cylindrical bodies of erectile tissue, each surrounded by a thick fibrous capsule called the tunica albuginea. Paired corpora cavernosa attach to the posterior portion of the ischiopubic rami (the crura of the penis) and converge anteriorly at the pubic symphysis. The paired bodies fuse with each other and are flexed inferiorly. The single corpus spongiosum begins as an expanded region called the bulb of the penis, which is attached to the inferior surface of the perineal membrane, and into which the urethra passes. The crura and bulb form the root of the penis. The corpus spongiosum with the urethra within it courses anteriorly to meet and fuse with the paired corpora cavernosa and form the body of the penis. The distal portion of the corpus spongiosum is expanded as the glans, which caps the distal ends of the paired corpora cavernosa. The external urethral orifice is at the tip of the glans. The three fused erectile bodies are surrounded by a deep (Buck) fascia, thin loose connective tissue, and thin, somewhat pigmented skin. The glans is covered by a redundant fold of skin called the prepuce (foreskin) and is removed if a child is circumcised. The posterior crural portion of the corpora cavernosa are covered with ischiocavernosus muscles, and the corpus spongiosum is covered by the paired bulbospongiosus muscles. Superficial transverse perineal muscles are also present at the posterior margin of the perineal membrane and attach to the perineal body.

The scrotum is a sac of pigmented skin and the dartos fascial layer, which contains smooth muscle fibers that produce the characteristic wrinkling of the skin. The scrotum is posteroinferior to the penis and is divided into two compartments by an internal septum. Each compartment contains a testis, epididymis, and the spermatic cord. Each testis is ovoid with a thick fibrous capsule, the tunica albuginea, from which incomplete connective tissue septa divide the interior into lobules. The lobules contain testosterone-producing interstitial cells (of Leydig) and coiled seminiferous tubules where spermatozoa (sperm) are produced. The seminiferous tubules converge toward the posteriorly located mediastinum to form tubules (straight tubules, rete testes, and efferent tubules), which convey sperm to the epididymis. The epididymis is the comma-shaped structure attached to the posterior surface of the testis and is composed of the highly convoluted ductus epididymis. The testis and epididymis are surrounded by a closed, double-layered peritoneal sac embryologically derived from the process vaginalis. The inner portion or the visceral layer of the tunica vaginalis is applied to the surface of the testis and epididymis and is continuous posteriorly with an outer, parietal layer of the tunica vaginalis. A small cavity with lubricating fluid separates the two layers (Figure 28-3).

The epididymis is continuous inferiorly with the ductus (vas) deferens, which courses superiorly to enter the superficial inguinal ring. The ductus deferens along with the testicular, deferential, and cremasteric arteries, pampiniform plexus of veins, genital branch of the genitofemoral nerve, autonomic nerve fibers, and lymphatic vessels are components of the spermatic cord. The testis, epididymis, and spermatic cord are encased in three fascial layers derived from layers of the anterior abdominal wall (Table 28-1).

scrotum anatomy

Figure 28-3. Layers of the scrotum. (Reproduced, with permission, from Lindner HH. Clinical Anatomy. East Norwalk, CT: Appleton & Lange, 1989:501.)

The testes are supplied by the testicular arteries that arise from the abdominal aorta, just inferior to the renal arteries. They course retroperitoneally to reach the deep inguinal ring, crossing anteriorly to the ureters and external iliac vessels. They traverse the inguinal canal to enter the scrotum through the superficial inguinal ring. Venous drainage of the testes is by the pampiniform plexus of veins, which follow a reverse course through the inguinal rings and canal, to become paired testicular veins near their entrance into the abdomen. Eventually, a single testicular vein is formed that drains into the IVC on the right side but enters the left renal vein on the left side. Lymphatic vessels ascend along the paths of the testicular vessels to drain lymph into lumbar and preaortic lymph nodes at the level of origin of the arteries. This high abdominal position of arterial origin and lymphatic drainage
reflects the embryological site where the testes were formed.

Table 28-1 • ORIGINS OF SPERMATIC CORD COVERINGS

Fascia

Abdominal Layer of Origin

Internal spermatic fascia

Transversalis fascia

Cremasteric fascia and muscle

Internal abdominal oblique muscle

External spermatic fascia

External abdominal oblique muscle



COMPREHENSION QUESTIONS

28.1 Which of the following is the male homologue of the female clitoris?
A. Epididymis
B. Vas deferens
C. Penis
D. Scrotum

28.2 The scrotum appears to have a slightly pigmented and wrinkled appearance. What is the explanation for this appearance?
A. Hyperkeratinized squamous epithelium
B. The tunica albuginea
C. The dartos fascia
D. The pampiniform plexus

28.3 An 18-year-old man is noted to have probable testicular cancer. He undergoes surgery. After incising the scrotum, the surgeon contemplates the approach to the parenchyma of the testes. Through which layer must the surgeon incise to reach the testicular parenchyma?
A. Buck fascia
B. Tunica albuginea
C. Dartos fascia
D. Scarpa fascia

28.4 A 7-year-old male comes in for a routine physical examination. The pediatrician notices that the right testis is enlarged and without tenderness. Transillumination reveals clear fluid which is present around the right testis. This fluid most likely occupies which space?
A. Tunica albuginea
B. External spermatic fascia
C. Tunica vaginalis
D. Cremasteric layer


ANSWERS
28.1 C. The penis in the male is the homologue to the clitoris in the female.
28.2 C. The dartos fascia, which consists of smooth muscle, gives the scrotum its characteristic slightly pigmented and wrinkled appearance.
28.3 B. Each testis is surrounded by a thick capsule, the tunica albuginea.
28.4 C. This patient most likely has a hydrocele, which is a fluid collection in the tunica vaginalis. This is a congenital condition formed when the testis descends through the inguinal canal together with some peritoneum. Peritoneal fluid sometimes accumulates in this space.


ANATOMY PEARL
 The root of the penis is defined as the crura and the bulb.
 The cremasteric muscle, which causes elevation of the testes in the cremasteric reflex, is innervated by the genital branch of the genitofemoral nerve.
 The testicular artery arises from the aorta just inferior to the renal arteries.
 The right testicular vein drains into the IVC, whereas the left one drains into the left renal vein.

References

Gilroy AM, MacPherson BR, Ross LM. Atlas of Anatomy, 2nd ed. New York: Thieme Medical Publishers; 2012:251, 257, 259−260. 

Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy, 7th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2014:206−210, 215. 

Netter FH. Atlas of Human Anatomy, 6th ed. Philadelphia, PA: Saunders; 2014: plates 358−360, 365.

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