Repro USMLE step 1 9-3 (6) Flashcards
This infant presents with a scrotal mass that is painless on palpation Illumination of the scrotum when a light is shined at its base is a positive transillumination test. This suggests that the patient has a cystic mass; a testicular hydrocele is one of the most common causes of painless scrotal enlargement in newborns. It is composed of a collection of serous fluid between the parietal and visceral layers of ?
the tunica vaginalis. Most cases are idiopathic. Testicular hydrocele in infants usually resolves on its own.
A defect in the pampiniform plexus would be described as having a “bag of worms” texture and would be characteristic of a varicocele. Problems with the inguinal lymphatics would usually result in?
elephantiasis and causes severe swelling. Direct problems with the body of the testis or epididymis that causes fluid accumulation would generally produce pain, and would be due to inflammation.
Testicular hydrocele is a fluid collection in the space between the parietal and visceral layers of the tunica vaginalis. A diagnosis can be made with?
a transillumination test. If the scrotum “lights up” when a light is shined at its base, the test is positive.
This patient presents with classic symptoms of benign prostatic hyperplasia (BPH), which include difficulty starting and maintaining a urine stream, feeling as though the bladder is never emptied, having the urge to urinate again soon after voiding, and pain on urination (dysuria). Finasteride can be used to treat this condition. Finasteride acts by inhibiting the conversion of testosterone (a steroid molecule) to dihydrotestosterone (DHT) by?
inhibiting the enzyme 5α-reductase. Normally DHT binds to the nuclear androgen receptors and stimulates mitogenic growth factors that cause stromal and epithelial hyperplasia along and promote development of secondary sexual characteristics (in men and women). DHT, not testosterone, is the culprit behind prostatic hyperplasia because of its slow dissociation from the prostatic nuclear androgen receptor. Inhibiting 5α-reductase, and thus DHT formation, leads to a reduction in the size of the prostate, providing relief of symptoms.
Muscarinic antagonists, such as oxybutynin are used to treat overflow incontinence. Flutamide, which acts by inhibiting the negative feedback of testosterone on gonadotropin secretion, is used primarily in conjunction with?
a gonadotropin-releasing hormone analog, such as leuprolide, in the treatment of metastatic prostate cancer. Ketoconazole is an antifungal agent that inhibits cytochrome P-450 enzymes and can be used to treat polycystic ovary syndrome.
First-line treatment of benign prostatic hyperplasia (BPH) is with α1-antagonists, which cause smooth muscle relaxation and offer symptomatic relief. Finasteride is another common treatment for?
BPH that inhibits 5α-reductase to decrease the synthesis of dihydrotestosterone (DHT). DHT is the stimulus for the prostate stromal hyperplasia seen in BPH.
The patient has a history of rheumatoid arthritis, and her use of NSAIDs has caused gastric ulcers. The medication prescribed for her gastric ulcers is most likely the cause of her symptoms, since her symptoms occurred after she started taking it. The findings of firmness and tenderness in her lower abdomen, vaginal bleeding, and amenorrhea suggest that the patient is pregnant. Misoprostol is?
a prostaglandin E1 analog prescribed to treat NSAID-induced gastric ulcers. In the gastrointestinal tract, misoprostol increases the secretion of mucus to protect the mucosal lining. Misoprostol is also used as an abortifacient because it induces uterine contractions and cervical ripening in pregnant women. Just remember, you don’t want to “Mis that the Ms. is pregnant!”
All patients with NSAID-induced ulcers should receive 8 weeks of proton-pump inhibitor (PPI) therapy. Older PPIs, such as omeprazole, are pregnancy class C (risk cannot be ruled out) and are often used to treat NSAID-induced ulcers in pregnant women. For this patient, the physician wanted to avoid the interaction between phenytoin and PPIs. (PPIs are associated with ?
inhibition of cytochrome P and have been shown to decrease biological clearance of phenytoin). However, a pregnancy test in this patient would have been warranted before prescription of misoprostol. This would have informed further management of this patient’s medications.
Cimetidine can cause galactorrhea in women and gynecomastia in men. However, it is not an abortifacient. Mifepristone is an abortifacient, but it is not prescribed for?
NSAID-induced gastric ulcers. Although omeprazole can cause abdominal pain, it is not an abortifacient. Sucralfate can cause constipation, which may lead to abdominal pain and tenderness. However, it does not cause vaginal bleeding.
Misoprostol is?
a prostaglandin E1 analog that increases secretion of mucus and decreases acid production in the gastrointestinal tract. It also induces uterine contractions and cervical ripening in pregnant women.
This patient presents with endometrial cancer that is staged and treated with total abdominal hysterectomy. While the cancer seems localized to the myometrium, the surgical team sends the tumor specimen as well as tissue inferior to the broad ligament for pathologic study. The histology described in the connective tissue is transitional epithelium, which is found in the urinary tract and ureters.
In women, the ureter courses just inferior to the uterine arteries at about 2 cm above the ischial spine. This puts the ureter at high risk for inadvertent injury when the uterine arteries are ligated during surgery, potentially leading to acute postoperative renal failure. The cardinal ligament is located inferior to the broad ligament and contains the blood vessels. Blind dissection of the inferior aspect of the cardinal ligament, which contains the uterine arteries, can result in damage to?
the ureter. This can be remembered with the mnemonic “water under the bridge” (water is the ureter, which runs under the uterine vessels, or the bridge). In this case, the inferior portion of the ureter was excised with the connective tissue, which explains the histopathologic findings, since the ureter and bladder are lined with transitional epithelium.
Concomitant adenocarcinoma of the sigmoid colon would appear as glandular structures, simple and tubular in appearance and lined with columnar epithelium. Metastatic endometrial carcinoma would have penetrated the myometrium and spread to the surrounding adventitia. Ovarian teratomas contain mature, normal tissue originating from?
all three types of embryonic tissue (ectoderm, endoderm, and mesoderm). Ureteral transitional cells arise only from mesoderm. Transitional cell carcinoma of the urethra is unlikely because the urethra is not near the broad ligament.
The ureter in women is at risk of?
accidental injury during hysterectomy or Caesarean section, potentially leading to acute postoperative renal failure.
This patient’s clinical presentation of a purulent vaginal discharge, fever, diffuse severe abdominal tenderness and extreme discomfort on bimanual examination of the cervix (cervical motion tenderness) and right adnexa is most consistent with a diagnosis of pelvic inflammatory disease (PID). PID is caused most commonly by Chlamydia trachomatis and/or Neisseria gonorrhoeae. PID, defined as a polymicrobial infection of the female reproductive organs, is a serious condition meriting prompt treatment. If left untreated, it can result in a number of chronic complications, such as chronic pelvic pain and infertility. PID may include salpingitis, endometritis, hydrosalpinx, and tubo-ovarian abscess formation. Classic physical exam findings are cervical motion tenderness (ie, the “chandelier sign” which is an informal term describing the raising of the arms towards the ceiling in response to intense pain) and purulent cervical discharge.
Acceptable first-line antibiotic regimens for the treatment of uncomplicated PID include:? .
ceftriaxone plus doxycycline; cefoxitin plus probenecid and doxycycline; or cefotaxime plus doxycycline.
These regimens are designed to provide coverage for a wide variety of pathogens, including C. trachomatis and N. gonorrhoeae. The combination of ceftriaxone plus doxycycline, for example, is often effective in treating PID because ceftriaxone, a third-generation cephalosporin, has good N. gonorrhoeae coverage, while doxycycline, a tetracycline antibiotic, has good C. trachomatis coverage. Note that it is particularly important for any PID antibiotic regimen to have both C. trachomatis and N. gonorrhoeae coverage since both organisms are often implicated in the pathogenesis of PID.
The combination of ceftriaxone and doxycycline alone would thus be an acceptable answer if this patient’s PID were uncomplicated. However, the right adnexal tenderness found on physical examination is strongly suggestive of a tubo-ovarian abscess, in which case the addition of either metronidazole or clindamycin is indicated. Either of these agents is indicated because anaerobic bacteria are often found in bacterial abscesses, and both agents have good anaerobe coverage.
The correct answer is therefore?
ceftriaxone, doxycycline, and metronidazole. Antimicrobial regimens consisting of either ciprofloxacin alone, clarithromycin alone, vancomycin and metronidazole, piperacillin and tazobactam, or trimethoprim and sulfamethoxazole provide inadequate coverage of C. trachomatis, N. gonorrhoeae and anaerobes, and so are not adequate treatment of complicated PID.
