Repro USMLE step 1 9-1 (2)

Question 1

This infant has microcephaly, hearing loss, hepatosplenomegaly, and a petechial rash. Furthermore, the mother discloses that she had fever, sore throat, and fatigue early in her pregnancy. In this setting, the most likely diagnosis is?

Answer 1

a congenital cytomegalovirus (CMV) infection. Pregnant women can become infected with CMV through sexual contact or organ transplantation. Pregnant women with CMV infection are typically free of symptoms but may have a mononucleosis-like illness, as described by this infant’s mother. Fetuses exposed to CMV during the first trimester may experience intrauterine growth retardation in addition to central nervous system damage with hearing and sight impairments. Intellectual disability can occur along with microcephaly. A classic feature of CMV is periventricular calcifications, which may be observed on a head CT scan.

Question 2

CMV is part of a group of microbes that cause ToRCHeS infections, alongside Toxoplasma gondii, Rubella, Cytomegalovirus, HIV, Herpes simplex virus-2, and Syphilis. Most ToRCHeS infections are transmitted from?

Answer 2

mother to fetus transplacentally; however, transmission during delivery (particularly with herpes simplex virus-2) is also possible in some cases. Any ToRCHeS infection can result in hepatosplenomegaly, jaundice, thrombocytopenia (petechial skin rash), and growth retardation.

Question 3

Congenitally acquired rubella is associated with cataracts, hearing loss, and congenital heart disease.
Congenitally acquired herpes simplex virus is associated with neonatal meningoencephalitis and vesicular, herpetic lesions.
Congenitally acquired HIV presents as?

Answer 3

recurrent infections and chronic diarrhea in neonates.

Congenitally acquired syphilis often results in stillbirth and hydrops fetalis. If the infant survives, he or she will have notched teeth, a saddle nose, saber shins, and sensorineural deafness.

Question 4

Congenital CMV infection manifests in neonates as?

Answer 4

hearing loss, seizures, petechial rash, microcephaly, and evidence of periventricular calcifications on CT of the head. Maternal manifestation may include a mononucleosis-like illness during pregnancy.

Question 5

This child is brought to the pediatrics clinic, and a medical student is performing a well-child examination. The medical student’s initial observations are provided, and the question asks for another developmental milestone associated with those observations.

Developmental milestones can be used by pediatricians to determine an infant’s or child’s motor, social, and verbal/cognitive age. Infants or children who are not meeting milestones may need assessment for potential developmental delay.

The first milestone mentioned is stranger anxiety, observed when the medical student walks in the room and the infant begins to cry and hide behind his mother. Stranger anxiety typically begins around 6 months of age. Furthermore, the infant is seen passing toys from hand to hand and sitting alone without his mother’s help, both milestones that are also present in infants around 6 months of age. Given these findings, we can be confident that this infant is about 6 months old. The answer choice that most accurately aligns with this infant’s development is?

Answer 5

rolling over. Another milestone seen in 6-month-old infants is the loss of the palmar primitive reflex.

Taking a first step typically occurs in infants between 10 and 12 months of age. Responding to his (or her) own name typically occurs in an infant at around 9 months of age. Loss of the Babinski sign typically occurs in infants around 12 months of age. Saying “ma-ma” and “da-da” with meaning typically occurs in infants around 10 months of age.

Question 6

Developmental milestones are useful for determining an infant’s or child’s motor, social, and verbal/cognitive progress. At 6 months of age, children typically display ?

Answer 6

stranger anxiety, loss of the palmar primitive reflex, the ability to roll and sit on their own, and the ability to pass toys from hand to hand.

Question 7

This patient presents with irregular menstrual cycles, hirsutism, and possible diabetes. She is most likely suffering from polycystic ovarian syndrome (PCOS), one of the most common endocrinopathies in women. In addition to hirsutism, PCOS is associated with infertility (secondary to oligo-ovulation), insulin resistance, hyperandrogenism, and obesity.
Symptoms of PCOS often develop after menarche and seem to be caused by intraovarian androgen excess, which causes anovulation and the formation of multiple ovarian cysts. These cysts stimulate excessive growth of follicles and hinder the maturation of a dominant follicle.

Multiple therapies are often required. Of note, oral contraceptive pills (OCPs) are the first-line treatment for PCOS. If treatment with OCPs yields unacceptable cosmetic results after six months, an antiandrogen, such as?

Answer 7

spironolactone, is added to treat hirsutism.

Spironolactone acts by blocking androgen receptors and inhibiting androgen biosynthesis; it is also a diuretic. Additional drugs for PCOS include gonadotropin analogs and clomiphene.

Ganirelix is a GnRH antagonist which would cause ovarian suppression. Furosemide is a diuretic drug that would have no efficacy against this patient’s hirsutism. Minoxidil would cause an increase in hair growth. Estrogen would not help this patient, whose estrogen levels are most likely already elevated due to her condition.

Question 8

Polycystic ovarian syndrome is characterized by elevated testosterone levels (resulting in hirsutism, anovulation), high levels of insulin, and high levels of luteinizing hormone. It may be treated with?

Answer 8

spironolactone, oral contraceptives, gonadotropin analogs, and clomiphene.

Question 9

This patient presents with burning on urination, malodorous green discharge, and erythematous vaginal mucosa. The presence of flagellated trophozoites on a wet mount of the discharge is observed confirming a diagnosis of trichomoniasis.

Trichomoniasis is a sexually transmitted infection (STI) characterized by vaginal itching, burning on urination, foul-smelling green discharge, and vaginal erythema. Vaginal pH may also be elevated (>4.5). It is caused by the protozoan parasite Trichomonas vaginalis.Treatment consists of a one-time dose of ?

Answer 9

metronidazole for the patient and her sexual partner. Partner treatment is necessary with this infection because in male patients this organism can cause asymptomatic urethritis.

Question 10

Ceftriaxone and azithromycin, for both the patient alone and with her partner, is the treatment regimen for chlamydia or gonorrhea. Chlamydia or gonorrhea infection usually presents with purulent vaginal discharge originating from an inflamed cervix. These infections may be, accompanied by cervical motion tenderness if they ascend into the upper genital tract, causing pelvic inflammatory disease. Fluconazole would be used to treat?

Answer 10

a yeast infection, such as candida. Candida vaginitis would present with a thick, cottage cheese-like, white discharge and KOH prep would reveal pseudohyphae instead of motile protozoa. Trichomonas is an STI, and although metronidazole is the correct treatment, it cannot be given to the patient alone. Both the patient and her partner need to be treated with metronidazole.

Question 11

This boy with an opening of the urethra on the dorsal aspect of the penis has simple epispadias (Think of dorsal/ventral with the penis being oriented superiorly against the lower abdomen–dorsal is the top of the penis, ventral is the bottom). This is a rare congenital defect caused by abnormal development of the genital tubercle. Depending on the level at which the paired primordia of the genital tubercle fuse, the defect may range from simple epispadias to bladder and bowel exstrophy. In female fetuses, the genital tubercle develops into?

Answer 11

the glans clitoris during gestation. Epispadias in a female can result in a bifid clitoris and a urethral cleft, leading to incontinence.

Question 12

Hypospadias is due to abnormal development of the urogenital folds which form the labia minora in females. The labia majora and the scrotum are derived from?

Answer 12

the labioscrotal swelling. The uterus is derived from the paramesonephric ducts. The inferior two-thirds of the vagina is derived from the vaginal plate of the urogenital sinus. The uterus, uterine tubes, cervix and superior third of the vagina is derived from the paramesonephric ducts. In males, this structure is lost.

Question 13

Epispadias results from a defect in the development of the genital tubercle, which is the embryologic precursor of ?

Answer 13

the glans penis and the glans clitoris

Question 14

This patient has a painful penile ulcer and inguinal lymphadenopathy with purulent discharge, a classic presentation of chancroid. Chancroid is a sexually transmitted disease caused by Haemophilus ducreyi, which is?

Answer 14

a gram-negative coccobacillus.

The genital lesions may begin as small papules that rapidly evolve into painful ulcers with erythematous bases that bleed easily with mechanical manipulation. Painful, swollen inguinal lymph nodes, often unilateral, develop in about 30% of infected persons. In 50% of these patients, the swollen lymph nodes will rupture and drain pus. An example of chancroid infection is displayed in the image below. Treatment options for chancroid include azithromycin, ceftriaxone, and ciprofloxacin.

Question 15

This child has been raised as a girl, although ambiguous genitalia were present at birth. Now that she is reaching puberty, her body is changing in ways that are inconsistent with that gender assignment. She is experiencing changes in her body mass and voice in addition to a lack of menstruation. These findings are most consistent with a diagnosis of?

Answer 15

5a-reductase deficiency. 5a-Reductase converts testosterone to dihydrotestosterone. Dihydrotestosterone is required for the development of the penis and scrotum during embryogenesis. An infant with 5a-reductase deficiency may be phenotypically female, with normal levels of testosterone, estrogen, and luteinizing hormone; however, an infant with this deficiency is genotypically male. The dramatic increase in testosterone levels during puberty causes the external genitalia to be masculinized and the development of male secondary sexual characteristics. Failure to menstruate is commonly reported by patients with 5a-reductase deficiency.

Question 16

Placental aromatase deficiency can cause masculinization of female infants (ambiguous genitalia) as mentioned in this patient’s history. However, in infancy, serum levels of testosterone and androstenedione would be elevated.

Female pseudohermaphroditism and ovotesticular disorder of sex differentiation would present with either?

Answer 16

internal female genitalia or mixed internal genitalia.

Complete androgen insensitivity would cause high levels of testosterone.

Double Y syndrome would present with a male phenotype from birth.

Question 17

5α-Reductase deficiency leads to failure of development of normal male external genitalia, often resulting in a phenotypically female 46,XY infant. The increase in testosterone levels during puberty often results in ?

Answer 17

masculinization of the external genitalia. Additionally, the adolescent may present with a report of primary amenorrhea.

Question 18

This patient presents with fever; generalized lymphadenopathy; and an erythematous, maculopapular rash on her palms and soles, as seen in the images. She also has a history of unprotected sex with multiple partners and a painless genital lesion. Her symptoms and history are a classic presentation of secondary, or disseminated, syphilis.
Syphilis is a sexually transmitted disease caused by the spirochete Treponema pallidum. It is characterized by fever, sore throat, malaise, a generalized maculopapular rash involving the palms and soles, condylomata lata (wart-like papules on the genitals), and generalized nontender lymphadenopathy. A preceding primary stage is characterized by a painless, indurated ulcer or chancre at the site of inoculation.

If left untreated, syphilis can progress to a late stage that is characterized by?

Answer 18

end-organ damage to the central nervous system, aorta, or musculoskeletal system. Long-term Treponema infection can destroy the vasa vasorum of the ascending aorta, leading to destruction and dilation of the vessel. The distorted aorta consequently affects the patency of the aortic valve. Treatment with penicillin is essential.

Question 19

The patient presents with hypertension that started after week 25 of pregnancy. She did not have hypertension prior to the pregnancy, which suggests a diagnosis of gestational hypertension. However, the presence of proteinuria in addition to hypertension is consistent with ?

Answer 19

preeclampsia. Although the elevated serum glutamic oxaloacetic transaminase level in this case may suggest HELLP syndrome, transaminitis can also be seen in preeclampsia due to decreased hepatic blood flow secondary to hypertension. In addition, risk factors for preeclampsia include nulliparity, African American ethnicity, extremes of age (<20 or >35 years), multiple gestation, molar pregnancy, renal disease (due to SLE or type 1 diabetes mellitus), a family history of preeclampsia, and chronic hypertension.

Question 20

Preeclampsia usually occurs after 20 weeks of gestation and manifests with hypertension, edema, and proteinuria. Other signs and symptoms can include headache, blurred vision, abdominal pain, altered mentation, and hyperreflexia. Risk factors for preeclampsia and eclampsia include pre-existing hypertension, diabetes, chronic renal disease, and autoimmune disorders. Definitive treatment is delivery. A major complication of preeclampsia is disseminated intravascular coagulation (DIC), confirmed and monitored by?

Answer 20

fibrin split products (eg, D-dimers), prothrombin time, partial thromboplastin time, and platelet count. Other complications of preeclampsia/eclampsia are acute fatty liver, acute tubular necrosis, and HELLP (Hemolysis, Elevated Liver enzymes, Low Platelet count) syndrome.

Question 21

Decreased creatinine is not commonly associated with preeclampsia, however a protein to creatinine ratio of 3.0 or higher can be useful for diagnosis. Preeclampsia has an increased incidence in patients with pre-existing elevated glucose levels as seen in diabetes. Preeclampsia can eventually lead to HELLP (Hemolysis, Elevated Liver enzymes, Low Platelet count) syndrome. Hemolysis in HELLP syndrome would lead to?

Answer 21

decreased levels of haptoglobin rather than increased levels. This syndrome also results in thrombocytopenia rather than thrombocytosis.

Question 22

Preeclampsia is characterized by hypertension, proteinuria, and edema at or after 24 weeks’ gestation. Major complications include disseminated intravascular coagulation (DIC), HELLP syndrome, and acute tubular necrosis. DIC is confirmed and monitored by?

Answer 22

fibrin split products (eg, D-dimers), prothrombin time, partial thromboplastin time, and platelet count.

Question 23

This male patient is found to have a rudimentary uterus and a mass in the inguinal canal (most likely undescended testes) on ultrasound. Biopsy of the mass confirms the presence of testicular tissue. The cell indicated by the arrow is a Sertoli cell. The only two nonspermatogenic cells in the seminiferous tubules are Sertoli cells and Leydig cells. Of these two, only Sertoli cells are within the tubules; Leydig cells reside in the interstitial spaces between the tubules.
During embryonic development, Sertoli cells secrete?

Answer 23

Müllerian-inhibiting factor (MIF), which causes the Müllerian ducts to regress, preventing the development of the female reproductive organs. Inadequate embryonal MIF activity can lead to persistent Müllerian duct syndrome (PMDS), in which a rudimentary uterus is present and testes are usually undescended, as seen in this patient.

Question 24

The other substances listed are not produced by the Sertoli cells of the testes. Testosterone and androstenedione are produced by ?

Answer 24

the Leydig cells of the testes. The SRY gene on the Y chromosome produces testis-determining factor. Dihydrotestosterone is a product of testosterone conversion, which occurs in the adrenal glands, not the testes.

Question 25

Sertoli cells secrete ?

Answer 25

Müllerian-inhibiting factor, which prevents the development of the female reproductive organs.

Question 26

NSAID use, as seen in this patient, can cause gastric ulcers through inhibition of prostaglandin production in the gastrointestinal (GI) tract, where prostaglandins help promote bicarbonate secretion and production and secretion of the mucous barrier, while reducing acid secretion. Misoprostol is a prostaglandin E1 analog that restores the action of prostaglandins in the GI tract, resulting in reduced secretion of gastric acid and increased production and secretion of the gastric mucous barrier. This characteristic makes the drug useful in decreasing the incidence of NSAID-induced peptic ulcers in patients with concomitant long-term use of NSAIDs. As a prostaglandin, misoprostol causes?

Answer 26

uterine cramps and is contraindicated in women of childbearing potential because of its abortifacient properties. In fact, misoprostol is frequently used for medical termination of pregnancy (in conjunction with mifepristone). Misoprostol has also been used off-label to induce cervical effacement (ripening) and labor. Other common adverse effects of misoprostol are diarrhea, nausea, and vomiti

Question 27

Misoprostol is a prostaglandin used to prevent gastric ulcers, but it is contraindicated in pregnancy because?

Answer 27

it can induce labor.

There is no current evidence that prostaglandins, such as misoprostol, can cause intrauterine growth restriction, neural tube defects, polyhydramnios, or closure of the of ductus arteriosus (In fact, prostaglandins are used to keep the ductus arteriosus patent in many patients with cardiovascular anomalies.) Although misoprostol can cause diarrhea after prolonged use, this is not a reason that it would be contraindicated for a pregnant woman.

Question 28

The 52-year-old nulliparous white patient presents with a red scaly patch on her right nipple with serosanguinous discharge, palpable axillary nodes, and a firm mass in her right breast. This points to a diagnosis of Paget disease of the breast. Paget disease of the breast consists of an eczematous patch on the nipple or areola, often with underlying ductal carcinoma (ipsilateral ductal carcinoma in situ or invasive ductal carcinoma) that is palpable on breast examination.

Histologic examination of the patch reveals?

Answer 28

large cells with prominent nucleoli and pale to clear ?halos? of cytoplasm in the epidermis, as shown in the image. Risk factors for breast cancer include nulliparity, early menarche, late menopause, obesity, high-fat diet, and a positive family history.

Question 29

Mucinous carcinomas are a rare form of invasive ductal carcinoma, which originate in the milk duct and have a gelatinous consistency due to extracellular mucus surrounding the tumor cells, unlike the firm mass seen in this patient

Infiltrating lobular carcinomas have cells presenting in a linear pattern within breast stroma but are often bilateral with multiple lesions in the same location, unlike the single mass seen in this patient.

Medullary carcinomas are often soft and fleshy, not firm like the mass seen in this patient, and they present with?

Answer 29

lymphocytic infiltration on histologic examination.

Epithelial hyperplasia, the proliferation of normal epithelial cells, is a type of fibrocystic change that often occurs in women older than 30 years; it is benign and not associated with Paget disease.

Question 30

Intraductal papillomas are characterized histopathologically by the presence of fibrovascular structures lined by ductal epithelium. Intraductal papillomas may be felt as small lumps behind or next to the nipple, but they are not associated with a scaly patch on the nipple.

Comedocarcinoma is a tumor with a ?cheesy? consistency and has a solid pattern with?

Answer 30

central necrosis; the duct will feel cord-like, and squeezing it will yield cheese-like material. It is not associated with Paget disease.

Paget disease of the breast presents with a unilateral eczematous patch on the nipple and serosanguinous nipple discharge. Patients should undergo excisional biopsy to check for ipsilateral ductal carcinoma in situ or invasive ductal carcinoma, which often occur with Paget disease of the breast. Histology shows large cells with prominent nucleoli and pale to clear ″halos″ of cytoplasm in the epidermis.