Rav Usmle Consult

Front 1

Fractional excretion of sodium is a very useful diagnostic in distinguishing prerenal ARF from intrinsic renal ARF.

Back 1

Fractional excretion of sodium is a very useful diagnostic in distinguishing prerenal ARF from intrinsic renal ARF. FENa+ is <1% in prerenal conditions, whereas it is
>1% in intrinsic renal conditions. Typically, acute tubular necrosis (ATN) from most conditions is associated with FENa+ of >1%, but there are a few exceptions.
Acute tubular necrosis (ATN) from radiocontrast is associated with a FENa+ of <1%.

Option C (Hepatorenal syndrome) is incorrect. Hepatorenal syndrome is a functional renal failure from severe hepatic disease that mimics prerenal states like hypovolemia. So the FENa+ is <1%.

Option D (Hypovolemia) is incorrect. Volume depletion results in avid renal reabsorption of salt resulting in a FENa+ of <1%.

Front 2

The most important manifestation of aminoglycoside (e.g., tobramycin, gentamicin, amikacin)

Back 2

The most important manifestation of aminoglycoside (e.g., tobramycin, gentamicin, amikacin) nephrotoxicity is ARF, which occurs in about 10% of patients receiving these drugs. Maintaining blood levels in the therapeutic range reduces but does not eliminate the risk of nephrotoxicity. ARF is usually mild and nonoliguric and is manifested by a rise in the serum creatinine level after about a week of therapy with one of the aminoglycosides. The prognosis for recovery of renal function after several days is excellent, although some patients may need dialysis support before recovery.

Front 3

acute allergic interstitial nephritis,

Back 3

Fever, rash, and peripheral eosinophilia in a patient with renal failure are highly suggestive of an acute allergic interstitial nephritis, particularly in this patient who has been taking intravenous nafcillin. The penicillins and sulfa-based antibiotics are common causes of this condition. The presence of urinary WBCs and WBC casts also supports this diagnosis.

Postinfectious glomerulonephritis could develop as long as 3 weeks after a group A streptococcal infection. A patient would present with new-onset hematuria, edema, and hypertension. There should be hematuria with red blood cell casts and proteinuria, but this is not seen in this case.

Acute tubular necrosis is basically acute renal failure secondary to toxic (myoglobin, in this case) or ischemic processes that damage tubular cells. WBC casts would be expected as well, but eosinophilia suggests an allergic interstitial nephritis.
Urosepsis) is incorrect. Urine WBCs would be present. WBC casts would be highly unlikely and are more suggestive of interstitial nephritis. Eosinophilia supports an allergic cause.

Front 4

Urethritis is

Back 4

Urethritis is defined as a mucopurulent discharge, greater than 5 white blood cells (WBCs) per high-power field (hpf), positive leukocyte esterase on first void-urine or more than 10 WBCs per hpf in first-void urine. The most appropriate first step when gonococci are not identified is to institute appropriate antibacterial therapy. This is either with doxycycline or azithromycin. Because Gram stains are not 100% sensitive or specific, nucleic amplification for gonorrhea should be undertaken.

Front 5

gonorr

Back 5

Treatment, Prevention, and Control
Ceftriaxone can be administered in uncomplicated cases; fluoroquinolone can be used in susceptible population; penicillin should be avoided because resistance is common
Doxycycline or azithromycin should be added for infections complicated by Chlamydia
For neonates, prophylaxis with 1% silver nitrate; ophthalmia neonatorum is treated with ceftriaxone
Prevention consists of patient education, use of condoms or spermicides with nonoxynol-9 (only partially effective), and aggressive follow-up of sexual partners of infected patients
Effective vaccines are not available

Front 6

renal cell carcinoma

Back 6

Pulmonary nodules are usually multiple, spherical, and variably sized. The chest radiograph from this patient shows multiple “cannonball” secondary lesions of various sizes. These are typical of renal cell carcinoma. Twenty percent of patients with renal cell carcinoma present with lung metastases.

Front 7

bilateral hydronephrosis due to ureteral compression;

Back 7

bilateral hydronephrosis due to ureteral compression; note how the ureters are tapered and characteristically drawn medially by the fibrotic process. This characteristic medial deviation of the ureter at the L4–L5 vertebral level is a classic radiographic picture of retroperitoneal fibrosis. Given a likely drug associated with this condition, ergotamine for the treatment of migraine this diagnosis is the most likely of the available answer choices.

Front 8

undescended testes

Back 8

The risk of malignancy remains between 10 to 40 times higher for undescended testes regardless of surgical descent. By performing orchiopexy, self-examination and surveillance for cancer is improved, but the risk itself is not altered.

Front 9

chancroid,/granuloma inguinale,

Back 9

chancroid, a condition of painful genital ulceration combined with very tender regional lymphadenopathy. Chancroid is caused by H. ducreyi and is uncommon in the United States. However, it is quite common in Africa and Southeast Asia. The inguinal lymph nodes can become liquified and form buboes.


Calymmatobacterium granulomatis) is incorrect. This is the cause of granuloma inguinale, which presents as a painless nodule that evolves to become a beefy-red, raised, granulomatous ulcer.

Front 10

There are a wide variety of types of renal disease in patients with SLE.

Back 10

There are a wide variety of types of renal disease in patients with SLE. Because the different types have different treatments, it is important to perform a renal biopsy to determine the exact form of renal disease and to determine tubulointerstitial and vascular disease. Once the pathologic determination has been made, therapy can be started.

Front 11

Arsenic trioxide:

Back 11

Arsenic trioxide: Cytopenia, nausea, vomiting, diarrhea, hepatotoxicity, prolongation of the QT interval, cardiac arrhythmias including torsades de pointes and complete heart block, acute promyelocytic leukemia differentiation syndrome and sudden death

Front 12

Bleomycin:

Back 12

Bleomycin: Pulmonary fibrosis ("bleomycin lung")

Front 13

Busulfan:

Back 13

Busulfan: Pulmonary fibrosis ("busulfan lung")

Front 14

Doxorubicin:

Back 14

Doxorubicin: Cardiotoxicity

Front 15

Edatrexate

Back 15

Edatrexate: Stomatitis, nausea, vomiting, diarrhea, hepatotoxicity, pulmonary toxicity and rash

Front 16

Cisplatin:

Back 16

Cisplatin: Nephrotoxicity and peripheral neuropathy

Front 17

Oxaliplatin:

Back 17

Oxaliplatin: Peripheral neuropathy, hypersensitivity, pulmonary fibrosis (rare) and abdominal pain

Front 18

Cyclophosphamide:

Back 18

Hemorrhagic cystitis

Front 19

Vincristine:

Back 19

Vincristine: Neurotoxicity

Front 20

Interferon α:
Interleukin 2

Back 20

Interferon α: Flu-like symptoms; cytopenias; anorexia and weight loss; fatigue; depression; and intensification or induction of autoimmune and inflammatory disorders
Interleukin 2: Flu-like symptoms; cytopenias; hypotension; capillary leak syndrome; acute kidney failure; adult respiratory distress syndrome; intensification or induction of autoimmune and inflammatory disorders

Front 21

Irinotecan:

Back 21

Irinotecan: Diarrhea (early and late), nausea and vomiting, cholinergic syndrome, myelosuppression

Front 22

Cytarabine:

Back 22

Cytarabine: Cerebral damage

Front 23

All-trans-retinoic acid (ATRA)syndrome

Back 23

All-trans-retinoic acid (ATRA) syndrome is a life-threatening complication of ATRA chemotherapy. It is characterized by respiratory distress (89%), fever (81%), pulmonary infiltrates (81%), weight gain (50%), pleural effusion (47%), renal failure (39%), pericardial effusion (19%), cardiac failure (17%), and hypotension (12%). Virtually all patients have at least three of these conditions. Most patients recover completely with high-dose dexamethasone treatment and discontinuation of ATRA therapy.

Front 24

Adverse effects of cyclophosphamide and ifosfamide

Back 24

Adverse effects of cyclophosphamide and ifosfamide include alopecia, nausea, vomiting, myelosuppression, and hemorrhagic cystitis. Nausea and vomiting are usually mild when cyclophosphamide is given orally, but they can be severe when given intravenously. The dose-limiting toxicity of cyclophosphamide is myelosuppression, whereas that of ifosfamide is usually hemorrhagic cystitis. This type of cystitis is characterized by symptoms of urinary frequency and irritation and by blood loss from the bladder. Ingestion of large amounts of fluid and the administration of mesna, a sulfhydryl reagent, can significantly reduce the incidence of cystitis. Mesna binds to acrolein, the toxic metabolite that causes cystitis, and converts it to an inactive substance.

Front 25

Acute pancreatitis is a common complication of

Back 25

Acute pancreatitis is a common complication of L-asparaginase chemotherapy. Interestingly, most patients do not present with elevated amylase levels.

Front 26

Tamoxifen therapy has a threefold increased relative risk for

Back 26

Tamoxifen therapy has a threefold increased relative risk for pulmonary embolism. The incidence of endometrial cancer is also increased.

Front 27

Cerebellar toxicity is a unique chemotherapy

Back 27

Cerebellar toxicity is a unique chemotherapy complication associated with high-dose cytarabine therapy caused by the accumulation of the toxic metabolite ara-uridine. High-dose cytosine arabinoside (HDARAC) neurotoxicity is dose-related and occurs in 60% of treated patients. The incidence of cerebellar toxicity approaches 30%, with irreversible ataxia reported in up to 16.7%.

Front 28

Neurotoxicity constitutes the common dose limiting toxicity with

Back 28

Neurotoxicity constitutes the common dose limiting toxicity with vincristine. Symptoms include peripheral paresthesia, jaw pain, seizures, constipation, and bladder dysfunction. Inadvertent intrathecal injection of vincristine is uniformly fatal.

Front 29

. The 36-year-old woman with hypertension is being treated with an ACE inhibitor, a beta blocker, and aldosterone receptor blocker.

Back 29

. The 36-year-old woman with hypertension is being treated with an ACE inhibitor, a beta blocker, and aldosterone receptor blocker. All the three medications are very well known to cause hyperkalemia. Therefore, a patient receiving all three drugs is at a high risk of developing hyperkalemia.

Front 30

Aspirin overdose

Back 30

Aspirin overdose is suggested by the history and would result in primary metabolic acidosis with respiratory alkalosis.

Front 31

five basic pathophysiologic mechanisms that can cause hypoxemia.

Back 31

List and explain the five basic pathophysiologic mechanisms that can cause hypoxemia.

Decreased inspired oxygen (PiO2): high altitude, nonpressurized airplane cabin.
Hypoventilation: decreased minute ventilation resulting in increased arterial carbon dioxide (CO2) that leads to hypoxemia. (CNS impairment, respiratory muscle fatigue, or neuromuscular disease).
Diffusion abnormality: diffuse interstitial pulmonary fibrosis.
Ventilation-perfusion (V/Q) abnormalities: mismatching of ventilation and perfusion.
Shunt: perfusion of nonventilated lung (pneumonia, pulmonary edema). Hypoxemia secondary to shunting is refractory to oxygen therapy.

Front 32

pH 7.43; PaO2 50; PaCO2 40)

Back 32

pH 7.43; PaO2 50; PaCO2 40) is correct. The clinical picture is consistent with aspiration pneumonia. A common finding in aspiration pneumonia is marked hypoxemia.

Front 33

pH 7.40; PaO2 80; PaCO2 50)

Back 33

pH 7.40; PaO2 80; PaCO2 50) is correct. The clinical picture is consistent with chronic bronchitis. Such a patient would retain CO2 at baseline as evidenced by the increased PaCO2, but normalized pH.

Front 34

When looking at blood gas results, remember these three handy tips:

Back 34

The partial pressures of oxygen and carbon dioxide in the blood are dependent on the following factors:

Neuromuscular control of ventilation.
Patent airways for ventilation.
Diffusion across the alveolar-capillary membrane.
Pulmonary capillary blood flow matching the areas of ventilation.

If the pCO2 is high the problem is poor ventilation.
If the pCO2 is high, look at the HCO3-. If there is chronic carbon dioxide retention, it will be high due to renal compensation. Giving oxygen to these patients can be disastrous as they rely on hypoxic drive to maintain respiration.
Administration of oxygen to hypoxic patients will improve or correct the pO2 in all cases except right-to-left shunt.

Oxygen is carried in the blood in an easily reversible combination with hemoglobin. Carotid and aortic body chemoreceptors detect low partial pressures of oxygen pO2.

Front 35

pCO2 will be high if
The pO2 will be low if
pCO2 will be low

Back 35

Arterial blood is sampled from a peripheral artery (usually the radial artery).
The pO2, pCO2, pH, bicarbonate (HCO3-), and oxygen saturations can be measured.

The pO2 will be low if atmospheric oxygen is low (e.g. at high altitude), if ventilation is poor (see below), if diffusion is reduced (interstitial lung disease), if there is a V/Q mismatch (pulmonary embolus [PE]), or if there is a right-to-left shunt (ventricular septal defect with Eisenmenger's phenomenon).
The pCO2 will be high if ventilation is inadequate. This may be due to reduced central drive (sedative drugs, cerebral trauma), neuromuscular disease (Guillain-Barré syndrome, myasthenia gravis), thoracic wall abnormalities (kyphoscoliosis, ankylosing spondylitis) or airways obstruction (chronic bronchitis).
The pCO2 will be low in hyperventilation due to anxiety or panic.

Front 36

Rhabdomyolysis

Back 36

Rhabdomyolysis is a result of damage to striated muscle, leading to an elevation of creatine kinase and myoglobin in the serum. This can lead to acute renal failure. Treatment is hydration and alkalization of the urine with IV bicarbonate. The serum potassium level occasionally can rise to dangerous levels. This condition responds poorly to glucose and insulin. Hemodialysis may be necessary in the presence of hyperkalemia.

Front 37

REATMENT OF RHABDOMYOLYSIS

Back 37

REATMENT OF RHABDOMYOLYSIS
Fluid replacement-be aggressive but aware of renal function
Urine alkalinization-controversial. Benefit: Increased solubility of uric acid, myoglobulin. Harmful: HCO3 could promote calcium deposition
Correct hyperkalemia
Management of hypocalcemia-avoid intravenous calcium unless tetany is present
Management of hypercalcemia-prevention is key. Intravenous fluid, furosemide
Correction of hypoalbuminemia-usually not necessary
Disseminated intravascular coagulation-usually resolves spontaneously
Dialysis-if necessary
Hyperphosphatemia-oral binders, dialysis
Fasciotomy-relief of compartment syndromes

Front 38

. Detrusor instability

Back 38

. Detrusor instability is also known as urge incontinence. It is important to know both terms for this condition as they are often used interchangeably on the examination. Urge incontinence is characterized by a sudden urge to urinate followed by release of a large volume of urine that completely empties the bladder. Nocturia is frequently associated with this condition.

Front 39

Stress

Back 39

Stress
Leakage associated with increased intra-abdominal pressure (coughing, sneezing)
Hypermobility of the bladder base frequently caused by lax perineal muscles

tx Pelvic muscle exercise; timed voiding; α-adrenergic drugs; estrogens; surgery

Front 40

Urge

Back 40

Urge Leakage associated with a precipitous urge to void Detrusor hyperactivity (outflow obstruction, bladder tumor, detrusor instability); idiopathic (poor bladder); compliance (radiation cystitis); hypersensitive bladder Bladder training; pelvic muscle exercise; bladder-relaxant drugs (anticholinergics, oxybutynin, tolterodine, imipramine)

Front 41

overflow

Back 41

overflow

Leakage from a mechanically distended bladder Outflow obstruction; enlarged prostate; stricture; prolapsed cystocele; acontractile bladder (idiopathic, neurologic [spinal cord injury, stroke, diabetes]) Surgical correction of obstruction; intermittent catheter drainage

Front 42

Functional

Back 42

Functional

Inability or unwillingness to void Cognitive impairment; physical impairment; environmental barriers (physical restraints, inaccessible toilets); psychological problems (depression, anger, hostility) Prompted voiding; garment and padding; external collection devices

Front 43

There are four main types of urinary incontinence according to mechanism

Back 43

. The most common type of incontinence in the elderly is urge incontinence, which is caused by detrusor overactivity and results in symptoms of an uncontrollable urge to micturate, frequency, and nocturia.

Stress incontinence is also common and is most often caused by pelvic muscle laxity with hypermobility of the bladder neck or surgical changes that result in an inability of the urethral sphincter to overcome bladder pressure (e.g., prostatectomy). Actions that produce transient increases in intra-abdominal pressure, such as coughing, sneezing, or straining, often precipitate urine leakage in stress incontinence.

Overflow incontinence is caused by urinary retention, which may result from medications, neurologic deficits such as autonomic dysfunction in diabetes, or mechanical obstruction as in benign prostatic hypertrophy (BPH). Patients complain of leakage of frequent small amounts of urine as bladder volume increases beyond a critical level to create sufficient pressure for urine loss.

Functional incontinence is an inability to make it to the bathroom in time. It is caused by physical functional disability, cognitive impairment, depression, physical restraints, and the like.
It is also important to recognize that frequently more than one mechanistic form of incontinence may be present in the same patient ("mixed incontinence"). Mixed incontinence, like so much of geriatrics, requires a multifaceted treatment approach, often involving balancing multiple competing treatment considerations.

Front 44

Overflow incontinenc

Back 44

Overflow incontinence is to the result of detrusor hypotonia or areflexia, which, in this patient, is a result of recent epidural anaesthesia. This is confirmed with an elevated postvoid residual volume (any value greater than 200 mL suggests overflow incontinence).

Front 45

What laboratory tests are helpful in evaluating incontinence?

Back 45

What laboratory tests are helpful in evaluating incontinence?
Postvoid residual is an easy initial test to obtain. After the patient voids, in general, there should be less than 50 mL of urine in the bladder. Postvoid residual is measured by ultrasound or catheterizing the patient in the office. A patient with an elevated postvoid residual (repeat measurements greater than 100-200 mL) may have an underlying neurologic disorder. The presence of an elevated postvoid residual is a relative contraindication to surgical treatment of GSI and to anticholinergic medications for DI. Catheterization also provides a good opportunity to obtain urine for analysis and culture.
Urinalysis and urine culture help to diagnose urinary tract infection. Blood work is required only if compromised renal function, diabetes, syphilis, or other systemic diseases are suspected.

Front 46

urogenital fistula, also called “bypass incontinence.”

Back 46

urogenital fistula, also called “bypass incontinence.” In the United States, these occur most commonly after pelvic surgery or irradiation, but the leading cause worldwide is childbirth. The diagnosis should be suspected when there is constant urinary drainage following difficult labor in a patient with poor medical care.

Front 47

Differential diagnosis of postoperative fever

Back 47

Differential diagnosis of postoperative fever
The differential diagnoses of the cause of fever are:

First 24 hours trauma response, pre-existing sepsis.
24-72 hours postoperatively-pulmonary atelectasis, pulmonary infection, infected intravenous site, trauma response (activation of the inflammatory response).
3-7 days postoperatively-chest infection, wound infection, urinary tract infection, anastomotic dehiscence, wound dehiscence.
7-10 days postoperatively-deep venous thrombosis, pulmonary embolus, pelvic abscess, subphrenic abscess.

Each system should be thoroughly examined, and temperature, pulse, blood pressure, and urine output should be noted.
Features of septicemia are shaking, chills, high temperature, tachycardia, hypotension, decreased urine output, and warm peripheries.

Front 48

The most common intraoperative complication of abdominal or vaginal hysterectomy is......

Back 48

The most common intraoperative complication of abdominal or vaginal hysterectomy is bleeding from the infundibulopelvic or utero-ovarian pedicle, the uterine vascular pedicle, or the vaginal cuff. When postoperative hemorrhage occurs, bleeding from the vaginal cuff can sometimes be identified and controlled vaginally. If bleeding is sufficient to cause hypotension, laparotomy may be required to tie off the bleeding vascular pedicle.
Infection is common to both procedures and is manifested by fever and lower abdominal pain. Examination often reveals tenderness and induration of the vaginal cuff, which indicative of pelvic cellulitis. This can usually be treated with antibiotic therapy. Administration of prophylactic cephalosporin perioperatively has proven beneficial in controlling infection in vaginal hysterectomies performed in premenopausal patients.
Injury to the ureter is the most serious complication of hysterectomy and usually occurs during the abdominal procedure, particularly during a difficult dissection for PID, endometriosis, or pelvic cancer. Ureteral injury can also occur during a vaginal hysterectomy. If not detected intraoperatively, fever and flank pain can develop postoperatively, and a ureterovaginal fistula or urinoma may become apparent 5 to 21 days after surgery. If noted intraoperatively, a ureteral injury can be repaired by implanting the proximal cut end of the ureter into the bladder or by anastomosing the proximal and distal ends of the transected ureter over a ureteric stent.
Intraoperative injury to the rectum or bladder, if recognized, should be repaired immediately. If a bladder repair is necessary, an indwelling catheter (suprapubic or transurethral) should be left on free drainage for 5 to 7 days. On rare occasions it may be necessary to back up an extensive rectal injury repair with a colostomy.

Front 49

Stevens-Johnson syndrome,

Back 49

Stevens-Johnson syndrome, or erythema multiforme major, is a collection of varied symptoms in response to a drug hypersensitivity. Sulfa drugs are a common culprit. Symptoms usually include dermatologic manifestations, most notably mucocutaneous blistering, and can be life threatening. Fever occurs in 85% of patients.

Front 50

most common causes of SJS in children.

Back 50

Drugs and Mycoplasma pneumoniae infections are the most common causes of SJS in children. Herpes simplex virus seems to have no role in the pathogenesis of SJS. Other precipitating factors are other viral infections, bacteria, syphilis, and deep fungal infections. The most common drugs implicated are nonsteroidal anti-inflammatory drugs (NSAIDs), followed by sulfonamides, anticonvulsants, penicillins, and tetracycline derivatives.

Front 51

This patient's low total serum calcium is low, because there is low albumin and signs of generalized protein loss along with proteinuria

Back 51

This patient's low total serum calcium is low, because there is low albumin and signs of generalized protein loss along with proteinuria. Approximately 40% of calcium is bound to albumin. However, the biologically active calcium is free, or ionized, calcium and it is this level that the body uses to monitor calcium homeostasis. A useful rule is that for every 1-g decrease in serum albumin below 4 g/dL, there is a 0.8 mg/dL decrease in total calcium. Therefore, to correct the calcium, we must add 1.6 mg/dL to get an overall corrected value of 9.2 mg/dL.

Front 52

2. How are serum calcium and serum albumin levels related?

Back 52

2. How are serum calcium and serum albumin levels related?
Approximately 50% of serum calcium is bound to albumin, other plasma proteins, and related anions, such as citrate, lactate, and sulfate. Of this, 40% is bound to protein, predominantly albumin, and 10-13% is attached to anions. The remaining 50% is unbound or ionized calcium. The total serum calcium level reflects both the bound and the unbound portions with a normal range of 2.1-2.5 mmol/L (8.5-10.5 mg/dL).
3. How is the total serum calcium corrected for a low serum albumin level?
Total serum calcium levels are corrected for hypoalbuminemia by adding 0.8 mg/dL to the serum calcium level for every 1.0 gm/dL that the albumin level is below 4.0 gm/dL. The adjusted level of total serum calcium correlates with the level of ionized calcium, which is the physiologically active form of serum calcium.

Front 53

Fever, rash, and peripheral eosinophilia in

Back 53

Fever, rash, and peripheral eosinophilia in a patient with renal failure are highly suggestive of an acute allergic interstitial nephritis, particularly in this patient who has been taking intravenous nafcillin. The penicillins and sulfa-based antibiotics are common causes of this condition. The presence of urinary WBCs and WBC casts also supports this diagnosis.

Front 54

Hypovolemia

Back 54

Hypovolemia) is correct. The elevated urine specific gravity, low urinary sodium, and BUN/creatinine ratio exceeding 20 is most consistent with prerenal or hypovolemic renal failure.

Front 55

cure in patients with clinically localized prostate cancer.

Back 55

External beam radiation can result in complete cure in patients with clinically localized prostate cancer.

Front 56

reasonable treatment option in patients with localized early prostate cancer.

Back 56

. Brachytherapy, implantation of radioactive bead in the prostate, is a reasonable treatment option in patients with localized early prostate cancer.

Surgery is recommended in patients under 65 years old. Patients with locally advanced disease, seminal vesicle involvement, or bone metastases are given hormonal treatment instead of surgery.

Front 57

stress dose steroids

Back 57

Methylprednisolone sodium succinate) is correct. The patient needs stress dose steroids. She is on prednisone, resulting in osteopenia, and now has had a significant stressor. Her adrenal function is suppressed by the exogenous steroids. Intravenous methylprednisolone sodium succinate (Solu-Medrol) is necessary in this situation.

Front 58

Pure seminoma)

Back 58

Pure seminoma) is correct. This is a proliferation of germ cells derived from spermatids or their precursors. This forms the basis of classification of testicular germ cell tumors i.e. seminomatous vs. non-seminomatous. This has important ramifications because treatment is markedly different between the two categories. All testicular cancers are definitively diagnosed by pathology, but can be inferred with reasonable accuracy by their tumor marker profile. Pure seminomas never produce AFP, and only rarely low levels of bHCG. LDH is a non-specific marker, but is correlated with tumor burden.

O

Front 59

Choriocarcinoma)

Back 59

Choriocarcinoma This is a non-seminomatous germ cell tumor characterized by the proliferation of syncytiotrophoblastic cells, similar to those of the placenta. As such, bHCG is markedly elevated in almost all cases.

Front 60

Embryonal cell tumor

Back 60

This is a non-seminomatous germ cell tumor characterized by the proliferation of anaplastic, embryonal-like cells. Levels of tumor markers can be variable, but at least one of bHCG or AFP should be elevated.

Front 61

Teratoma)

Back 61

This is a non-seminomatous germ cell tumor characterized by the proliferation of elements from all three germ layers – ectoderm, mesoderm, and endoderm. Unlike their female counterpart, testicular teratomas have an increased risk of malignancy. Tumor markers are usually elevated but non-specific. A negative bHCG and AFP is more suggestive of a seminoma.

Front 62

Yolk sac tumor) i

Back 62

Option E (Yolk sac tumor) is incorrect. This is a non-seminomatous germ cell tumor characterized by the proliferation of malignant endodermal cells, and is also known as an endodermal sinus tumor. This is distinguished from other germ cell tumors by a high AFP level.

Front 63

Testicular Cancer

Back 63

Testicular Cancer
Most commonly found in men between ages 15 to 40 years
The primary risk factor is cryptorchidism
Symptoms and Signs

Most commonly presents with painless swelling of the testicle
Hormone-secreting tumors can produce gynecomastia
Metastases to lung can produce respiratory distress

Evaluation

CT scans for staging
Serum hCG and AFP can help classify the tumor. Both markers may be present in nonseminomatous germ cell tumors and will be absent in seminomas

Treatment

Tumors restricted to the testicle can be treated with radical orchiectomy
Seminomas can be cured with radiation therapy
Nonseminomatous germ cell tumors or metastatic tumors can be treated with chemotherapy using cisplatin, etoposide, and bleomycin

Prognosis: Depends on the type of tumor, but patients with stage I tumors have a survival rate greater than 95% and patients with stage III tumors have a 70% cure rat

Front 64

urinary tract infection (UTI) caused by Proteus mirabilis, a motile organism that commonly causes UTIs

Back 64

This girl has a urinary tract infection (UTI) caused by Proteus mirabilis, a motile organism that commonly causes UTIs and renal stones and is unique among urinary tract pathogens in its splitting of urea to form NH4 and CO2. This raises the pH of the urine, making it a more hospitable environment for pathogens. Sometimes, infection with Proteus causes hyperammonemia and central nervous system manifestations. Assessing this patient’s serum ammonia levels would alert the physician to possible impending complications.