Pelvis Board Review Cases

Case 1. Your patient is in the first stage of labor. You need to assess the degree of cervical dilation so you perform a rectal exam. How are you able to assess cervical dilation using this procedure? What other structures can be palpated during a rectal exam in a female? Your patient has requested a pudendal nerve block to reduce the pain of delivery. How would you administer a pudendal nerve block? What area would be anesthetized by this block? Labor has progressed into the second stage and the baby’s head has descending into the pelvic cavity (true pelvis). The head has already passed through the superior pelvic aperture (pelvic inlet); your job is to guide it through the inferior pelvic aperture (pelvic outlet). What are the boundaries of these two apertures? It looks like the baby’s head is quite large and might tear the vaginal opening. You decided to perform a mediolateral episiotomy. What is an episiotomy? Explain the difference between a mediolateral episiotomy and a median episiotomy. Name the structures that would be cut in each type.

Case 2. Your patient has a malignant tumor on his left testicle. The cancer spreads via the lymphatic system and begins to invade the patient’s lymph nodes. Which group of lymph nodes would the cancer invade first? Would your answer be the same if the cancer was in the scrotum?

Case 3. Your female patient has an infected vestibular gland. Is the infection located within the superficial or deep perineal space (pouch)? Name the other structures located in this space in the female. What structure separates the superficial perineal space from the deep perineal space? Your male patient has an infected bulbourethral gland. Is the infection located within the superficial or deep perineal space (pouch)? Name the other structures located in this space in the male. What structure separates the deep perineal space from the pelvic diaphragm?

Case 4. Upon performing a rectal exam, you discover that your patient has an enlarged prostate gland. How were you able to make this observation while performing a rectal exam? What other structures can be palpated during this type of exam in a male? Your patient complains that he is having problems urinating. Explain how prostatic hypertrophy could hinder the flow of urine. Name the three parts of the male urethra that urine must pass through to exit the body. Where is each of these parts located? If your patient’s enlarged prostate is due to prostatic cancer rather than benign hypertrophy, what group of nodes would the cancer spread to?

Case 5. After having her fourth child, a woman complains that she feels pressure in her pelvic region – similar to the pressure felt when “bearing down”. You perform a vaginal exam and discover that the cervix is protruding into the inferior portion of the vagina. What structures can normally be palpated in a vaginal exam? What has happened to your patient? What muscles and ligaments normally support the uterus?

Practice questions

1. Following prostate surgery, your male patient is able to obtain an erection but cannot ejaculate. The nerve fibers most likely damaged during surgery are the:

A. pelvic splanchnics
B. sympathetic fibers that synapsed in the inferior hypogastric plexus
C. sympathetic fibers that synapsed in the chain ganglia
D. somatic fibers in the sacral plexus

2. Following childbirth, a female patient has developed urinary incontinence. Her condition would improve by strengthening the:

A. levator ani muscle
B. piriformis muscle
C. deep transverse perineal muscle
D. obturator internus muscle

3. Which of the following statements concerning the anal canal is TRUE:

A. internal hemorrhoids are painful to remove
B. lymphatic drainage inferior to the pectinate line is via the superficial inguinal nodes
C. anal mucosa superior to the pectinate line is derived from ectoderm
D. veins draining inferior to the pectinate line are tributaries of the portal system

4. While performing a hysterectomy, you must ligate the uterine artery. Due to its close relationship to the uterine artery, which structure is most likely at risk of being inadvertently severed?

A. pudendal artery
B. ovarian artery
C. ureter
D. round ligament of the uterus

5. A baby boy is born with hypospadias. Which of the following structures failed to fuse during development:

A. anal folds
B. labioscrotal swellings
C. paramesonephric ducts
D. urethral folds

Pelvis Board Review Answers

Case 1. The cervix, as well as the posterior vaginal wall, ischial spines, sacrospinous ligaments, ischial tuberosities, sacrum, coccyx, and ischioanal fossae can be palpated during a rectal exam in a female. Of course the wall of the rectum itself can also be examined. Pudendal block: the ischial spine and sacrospinous ligament is palpated through the vagina. Anesthesia is injected in this region where the pudendal nerve passes around the ischial spine. The perineum would be anesthetized including the lower ¼ of the vagina. The anterior portion of the perineum that is innervated by the ilioinguinal nerve would be anesthetized if an ilioinguinal nerve block was performed. The boundaries of the superior pelvic aperture are: superior aspect of the pubic symphysis, pubic crest, pectineal line, arcuate line of ilium, anterior border of the sacrum including the promontory. The boundaries of the inferior pelvic aperture are: inferior aspect of the pubic symphysis, ischiopubic rami, ischial tuberosities, sacrotuberous ligaments, tip of the coccyx. An episiotomy is a surgical incision in the perineum, made to enlarge the vaginal opening during childbirth. A median episiotomy is cut in the median plane (anterior/posterior direction) while the mediolateral episiotomy starts at the midline and then turns laterally and posterior. Structures cut in a median incision: skin, vaginal wall (mucosa), perineal body and portions of muscles that attach to it such as bulbospongiosus and levator ani. Structures cut in a mediolateral incision: skin, vaginal wall and the bulbospongiosus muscle.

Case 2. The testes drain to the lumbar (lateral aortic) and preaortic nodes within the abdomen because their development began on the posterior abdominal wall. If the scrotum was diseased, the infection would first drain to the superficial inguinal nodes (the nodes that receive drainage from the perineum).

Case 3. The female patient’s infection is located within the superficial perineal space. Other structures in the superficial space are the bulb of the vestibule, the bulbospongiosus muscle, the ischiocavernosus muscle, the clitoris and its crura, and the terminal portions of the urethra and vagina. The perineal membrane (inferior fascia of UG diaphragm) separates the superficial perineal space from the deep perineal space. The male patient’s infection is located within the deep perineal space. Other structures located in the deep space are the perineal vessels and nerves, the dorsal vessels and nerves of the penis, the sphincter urethrae muscle, the deep transverse perineal muscle and the membranous urethra. The deep perineal space is separated from the pelvic diaphragm by the superior fascia of the UG diaphragm.

Case 4. The prostate (lateral and posterior lobes) can be palpated on the anterior wall of the rectum (anterior and median lobes cannot be palpated). Other structures that can be palpated include the seminal vesicles, ampulla of the ductus deferens, bulb of the penis, ischial spines, sacrospinous ligaments, ischial tuberosities, sacrum, coccyx, ischioanal fossae, and the wall of the rectum. Since the prostatic urethra passes through the prostate gland, any enlargement of the gland could potentially compress the urethra. The three parts are: prostatic urethra located within the prostate gland, membranous urethra located within the UG diaphragm, and spongy urethra located with the corpus spongiosum of the penis. Prostatic cancer spreads to the internal iliac nodes.

Case 5. The structures that can be palpated in a vaginal exam include: vagina, cervix, ischial spines, ovarian cysts, bladder, urethra, perineal body, loops of intestine in the pouch of Douglas, ureters, UG diaphragm. Your patient’s problem is that the uterus has prolapsed into the vagina. Supports of the uterus include the pelvic diaphragm, the transverse cervical (cardinal) ligaments, the uterosacral ligaments, and the pubocervical ligaments. Although not part of the case, recall that the other two common relaxations are cystoceles (herniation of the bladder through the anterior vaginal wall) and rectoceles (herniation of the rectum into the posterior vaginal wall).

Practice questions:

1. B
2. A
3. B
4. C
5. D

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