An 11-year-old girl presents to the pediatrician with her mother, who is concerned about her sexual development. She mentions that she herself experienced the onset of menses at the age of 10.5 years, while her daughter has still not had a menstrual period. However, she is otherwise a healthy girl with no significant medical problems since birth. On physical examination, her vital signs are stable. Evaluation of breast and pubic hair are Tanner stage 2. The pediatrician reassures the mother that her daughter's sexual development is within the normal range for girls and there is nothing to worry about at present. Which is a sign of Tanner stage 2?
Q52
A 14-year-old girl is brought to the physician for evaluation of her short stature. She was born at term, and her birth length was normal. She has not yet attained menarche. Her mother is 162 cm (5 ft 4 in) tall and her father is 177 cm (5 ft 10 in) tall. She is at the 3rd percentile for height and 40th percentile for weight. Vital signs are within normal limits. Breast and pubic hair development are Tanner stage 2. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in diagnosis?
Q53
A 6-year-old boy is brought to the physician by his mother for coughing, nasal congestion, and intermittent wheezing for the past 2 months. The child has a history of eczema. Since birth, he has had three upper respiratory tract infections that resolved without treatment, and one episode of acute otitis media treated with antibiotics. His family moved into affordable housing 3 months ago. His temperature is 37.2°C (98.9°F), pulse is 120/min, respirations are 28/min, and blood pressure is 90/60 mmHg. There are scattered wheezes on pulmonary examination. Which of the following is the most appropriate next step in management?
Q54
A 5-year-old girl is brought to the emergency department because of abdominal pain, vomiting, and diarrhea for 6 days. Her mother says that over the last 24 hours she has developed a rash and has been urinating less frequently than usual. One month ago, she had a 3-day episode of high fever and sore throat that subsided without medical treatment. She appears weak. Her temperature is 37.7°C (99.8°F), pulse is 120/min, respirations are 28/min, and blood pressure is 114/72 mm Hg. Examination shows petechiae on the trunk and jaundice of the skin. The abdomen is diffusely tender with no peritoneal signs. Neurological examination shows no abnormalities. Laboratory studies show:
Hemoglobin 8 g/dL
Mean corpuscular volume 85 μm3
Leukocyte count 16,200/mm3
Platelet count 38,000/mm3
Serum
Blood urea nitrogen 43 mg/dL
Creatinine 2.9 mg/dL
pH 7.0
Urine dipstick is positive for blood and protein. A blood smear shows schistocytes and normochromic, normocytic cells. In addition to supportive treatment, which of the following is the most appropriate next step in management of this patient?
Q55
An 11-year-old boy with a history of attention deficit disorder presents to a general medicine clinic with leg pain. He is accompanied by his mother. He reports dull, throbbing, diffuse pain in his bilateral lower extremities. He reports that the pain feels deep in his muscles. He has awakened several times at night with the pain, and his symptoms tend to be better during the daylight hours. He denies fatigue, fever, or pain in his joints. On physical examination, his vital signs are stable, and he is afebrile. Physical examination reveals full range of motion in the hip and knee joints without pain. He has no joint effusions, erythema, or warmth. What is the next best step in management?
Q56
A 15-year-old boy is brought to the emergency department one hour after sustaining an injury during football practice. He collided head-on into another player while wearing a mouthguard and helmet. Immediately after the collision he was confused but able to use appropriate words. He opened his eyes spontaneously and followed commands. There was no loss of consciousness. He also had a headache with dizziness and nausea. He is no longer confused upon arrival. He feels well. Vital signs are within normal limits. He is fully alert and oriented. His speech is organized and he is able to perform tasks demonstrating full attention, memory, and balance. Neurological examination shows no abnormalities. There is mild tenderness to palpation over the crown of his head but no signs of skin break or fracture. Which of the following is the most appropriate next step?
Q57
A 3-year-old boy is brought to your pediatrics office by his parents for a well-child checkup. The parents are Amish and this is the first time their child has seen a doctor. His medical history is unknown, and he was born at 39 weeks gestation. His temperature is 98.3°F (36.8°C), blood pressure is 97/58 mmHg, pulse is 90/min, respirations are 23/min, and oxygen saturation is 99% on room air. The child is in the corner stacking blocks. He does not look the physician in the eye nor answer your questions. He continually tries to return to the blocks and becomes very upset when you move the blocks back to their storage space. The parents state that the child has not begun to speak and often exhibits similar behaviors with toy blocks he has at home. On occasion, they have observed him biting his elbows. Which of the following is the best next step in management?
Q58
A 6-year-old boy is brought to the physician because of right hip pain that started that afternoon. His mother reports that he has also been limping since the pain developed. He says that the pain worsens when he moves or walks. He participated in a dance recital yesterday, but his mother believes that he was not injured at the time. He was born at term and has been healthy except for an episode of nasal congestion and mild cough 10 days ago. His mother has rheumatoid arthritis and his grandmother has osteoporosis. He is at the 50th percentile for height and 50th percentile for weight. His temperature is 37.5°C (99.6°F), pulse is 105/min, respirations are 16/min, and blood pressure is 90/78 mm Hg. His right hip is slightly abducted and externally rotated. Examination shows no tenderness, warmth, or erythema. He is able to bear weight. The remainder of the examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 12.3 g/dL, a leukocyte count of 8,500/mm3, and an erythrocyte sedimentation rate of 12 mm/h. Ultrasound of the right hip shows increased fluid within the joint. X-ray of the hips shows no abnormalities. Which of the following is the most likely diagnosis?
Q59
A 5-week-old male infant is brought to the physician by his mother because of a 4-day history of recurrent nonbilious vomiting after feeding. He was born at 36 weeks' gestation via spontaneous vaginal delivery. Vital signs are within normal limits. Physical examination shows a 2-cm epigastric mass. Further diagnostic evaluation of this patient is most likely to show which of the following?
Q60
An otherwise healthy 10-day-old boy is brought to the physician by his parents because of progressively enlarging breasts bilaterally for the last 4 days. The parents report that they have sometimes noticed a discharge of small quantities of a white liquid from the left breast since yesterday. During pregnancy, the mother was diagnosed with hypothyroidism and was treated with L-thyroxine. The patient's maternal grandmother died of breast cancer. The patient currently weighs 3100-g (6.8-lb) and is 51 cm (20 in) in length. Vital signs are within normal limits. Examination shows symmetrically enlarged, nontender breasts, with bilaterally inverted nipples. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?
Growth/Development US Medical PG Practice Questions and MCQs
Question 51: An 11-year-old girl presents to the pediatrician with her mother, who is concerned about her sexual development. She mentions that she herself experienced the onset of menses at the age of 10.5 years, while her daughter has still not had a menstrual period. However, she is otherwise a healthy girl with no significant medical problems since birth. On physical examination, her vital signs are stable. Evaluation of breast and pubic hair are Tanner stage 2. The pediatrician reassures the mother that her daughter's sexual development is within the normal range for girls and there is nothing to worry about at present. Which is a sign of Tanner stage 2?
A. Pubarche
B. Adrenarche
C. Menarche
D. Thelarche (Correct Answer)
E. Coarse pubic hair
Explanation: ***Thelarche***
- **Thelarche** refers to the initial development of breast buds, which is the defining characteristic of **Tanner stage 2** breast development.
- This stage indicates the beginning of puberty, marked by a slight elevation of the breast and papilla, forming a small mound.
*Pubarche*
- **Pubarche** refers to the appearance of **pubic hair**, which is typically seen in **Tanner stage 2** for pubic hair development, but not breast development.
- While girls often experience pubarche around the same time as thelarche, the term specifically describes pubic hair growth, not breast development.
*Adrenarche*
- **Adrenarche** is the maturation of the adrenal cortex, leading to increased production of adrenal androgens and typically precedes the physical changes of puberty.
- It refers to the biochemical process of adrenal androgen secretion, not a specific physical sign of **Tanner stage 2** development.
*Menarche*
- **Menarche** is the first menstrual period, which occurs much later in puberty, typically after a significant progression through **Tanner stages 2-4**.
- This event signifies reproductive maturity and is not present at the initial stage of breast budding.
*Coarse pubic hair*
- The presence of **coarse pubic hair** indicates a more advanced stage of pubic hair development, typically **Tanner stage 3 or 4**, as hair becomes darker and coarser.
- **Tanner stage 2** pubic hair is usually sparse, long, straight, and lightly pigmented.
Question 52: A 14-year-old girl is brought to the physician for evaluation of her short stature. She was born at term, and her birth length was normal. She has not yet attained menarche. Her mother is 162 cm (5 ft 4 in) tall and her father is 177 cm (5 ft 10 in) tall. She is at the 3rd percentile for height and 40th percentile for weight. Vital signs are within normal limits. Breast and pubic hair development are Tanner stage 2. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in diagnosis?
A. Measurement of serum thyroid-stimulating hormone concentration
B. Measurement of serum insulin-like growth factor concentration
C. Genetic karyotyping
D. X-ray of the hand and wrist (Correct Answer)
E. MRI of the brain
Explanation: ***X-ray of the hand and wrist***
- An **X-ray of the hand and wrist** is used to determine **bone age**, which is crucial for evaluating short stature by comparing skeletal maturity to chronological age.
- In a 14-year-old girl with short stature and delayed puberty (Tanner stage 2, no menarche), a **delayed bone age** would suggest a constitutional growth delay, which is a common cause of short stature.
*Measurement of serum thyroid-stimulating hormone concentration*
- While **hypothyroidism** can cause short stature and delayed puberty, there are no other clinical signs (e.g., fatigue, weight gain, cold intolerance) to strongly suggest this diagnosis in this patient.
- A TSH measurement would typically be considered after initial screening tests, or if other symptoms are present.
*Measurement of serum insulin-like growth factor concentration*
- **Insulin-like growth factor 1 (IGF-1)** is used to screen for **growth hormone deficiency**, but this is usually evaluated after bone age assessment.
- Growth hormone deficiency is less likely without other symptoms or a clear growth curve deceleration.
*Genetic karyotyping*
- **Genetic karyotyping** is indicated if **Turner syndrome** (XO karyotype) is suspected, which could cause short stature and primary amenorrhea.
- However, the patient's normal birth length and lack of characteristic dysmorphic features make it a less immediate first step compared to bone age assessment.
*MRI of the brain*
- An **MRI of the brain** would be considered if there was suspicion of a **pituitary or hypothalamic tumor** causing growth hormone deficiency or delayed puberty.
- There are no specific neurological symptoms or signs of increased intracranial pressure to warrant a brain MRI as the initial diagnostic step in this case.
Question 53: A 6-year-old boy is brought to the physician by his mother for coughing, nasal congestion, and intermittent wheezing for the past 2 months. The child has a history of eczema. Since birth, he has had three upper respiratory tract infections that resolved without treatment, and one episode of acute otitis media treated with antibiotics. His family moved into affordable housing 3 months ago. His temperature is 37.2°C (98.9°F), pulse is 120/min, respirations are 28/min, and blood pressure is 90/60 mmHg. There are scattered wheezes on pulmonary examination. Which of the following is the most appropriate next step in management?
A. Throat culture
B. Skin prick testing
C. Flow cytometry for B cells
D. Dihydrorhodamine 123 test
E. Trial of bronchodilator (albuterol) (Correct Answer)
Explanation: ***Trial of bronchodilator (albuterol)***
- The patient's history of **eczema**, recurrent respiratory symptoms (coughing, nasal congestion, wheezing), and the finding of **scattered wheezes** on examination strongly suggest **asthma**. A trial of a **short-acting bronchodilator** like albuterol is the most appropriate initial step to confirm the diagnosis and provide symptomatic relief.
- If the wheezing and other respiratory symptoms improve significantly with albuterol, it further supports a diagnosis of **asthma**, which is a common condition in children with a history of atopy.
*Throat culture*
- A throat culture is used to diagnose **bacterial pharyngitis** (e.g., Group A Streptococcus), which presents with throat pain, fever, and often lacks the prominent wheezing seen in this patient.
- The patient's primary symptoms, especially the intermittent wheezing, are not typical for a bacterial throat infection.
*Skin prick testing*
- **Skin prick testing** is used to identify specific **allergens** that might trigger asthmatic symptoms. While allergies are often associated with asthma, this test is usually performed *after* a diagnosis of asthma has been established and initial management strategies have been implemented.
- It is not the most appropriate *initial* step to address acute or subacute respiratory symptoms with wheezing.
*Flow cytometry for B cells*
- **Flow cytometry for B cells** is typically used to investigate conditions like **immunodeficiencies** or **lymphoproliferative disorders**.
- Although the patient has a history of recurrent infections, his infections have been relatively mild (URI, one AOM) and resolved, making a severe B cell deficiency less likely to be the primary cause of his current wheezing.
*Dihydrorhodamine 123 test*
- The **dihydrorhodamine (DHR) 123 test** is used to diagnose **chronic granulomatous disease (CGD)**, a rare **primary immunodeficiency** characterized by recurrent, severe bacterial and fungal infections.
- The patient's history of infections is not severe or unusual enough to warrant immediate testing for CGD, and his predominant symptom of wheezing is not a primary manifestation of CGD.
Question 54: A 5-year-old girl is brought to the emergency department because of abdominal pain, vomiting, and diarrhea for 6 days. Her mother says that over the last 24 hours she has developed a rash and has been urinating less frequently than usual. One month ago, she had a 3-day episode of high fever and sore throat that subsided without medical treatment. She appears weak. Her temperature is 37.7°C (99.8°F), pulse is 120/min, respirations are 28/min, and blood pressure is 114/72 mm Hg. Examination shows petechiae on the trunk and jaundice of the skin. The abdomen is diffusely tender with no peritoneal signs. Neurological examination shows no abnormalities. Laboratory studies show:
Hemoglobin 8 g/dL
Mean corpuscular volume 85 μm3
Leukocyte count 16,200/mm3
Platelet count 38,000/mm3
Serum
Blood urea nitrogen 43 mg/dL
Creatinine 2.9 mg/dL
pH 7.0
Urine dipstick is positive for blood and protein. A blood smear shows schistocytes and normochromic, normocytic cells. In addition to supportive treatment, which of the following is the most appropriate next step in management of this patient?
A. Hemodialysis (Correct Answer)
B. Levofloxacin therapy
C. Platelet transfusion
D. Red blood cell transfusions
E. Plasmapheresis
Explanation: **Hemodialysis**
* This patient's presentation is consistent with **Hemolytic Uremic Syndrome (HUS)**, characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury.
* The presence of severe **acute kidney injury (BUN 43 mg/dL, Creatinine 2.9 mg/dL)** and **metabolic acidosis (pH 7.0)** indicates a need for urgent renal replacement therapy, making hemodialysis the most appropriate next step to manage these life-threatening complications.
*Levofloxacin therapy*
* Antibiotic therapy with **fluoroquinolones** is generally not recommended in typical HUS (often associated with Shiga toxin-producing E. coli) as it can potentially worsen the disease by increasing toxin release.
* There is no indication of an active bacterial infection requiring levofloxacin, and empirical antibiotic use without culture results is not appropriate for HUS management.
*Platelet transfusion*
* Platelet transfusions are typically **contraindicated** in HUS if the platelet count is above 10,000-20,000/mm³ or if there is no active severe bleeding, as they can exacerbate microvascular thrombosis.
* The patient's platelet count is 38,000/mm³, and while low, there's no mention of active severe bleeding, making routine platelet transfusion potentially harmful.
*Red blood cell transfusions*
* While the patient has severe anemia (Hb 8 g/dL), red blood cell transfusions are a **supportive measure** to manage anemia and are often required in HUS.
* However, managing the life-threatening renal failure and acidosis through hemodialysis takes precedence over immediate red blood cell transfusion as the most appropriate *next step* in overall management.
*Plasmapheresis*
* Plasmapheresis is primarily used in **atypical HUS (aHUS)** and thrombotic thrombocytopenic purpura (TTP), which are distinct from typical HUS caused by Shiga toxin-producing E. coli.
* For typical HUS, which is likely given the antecedent gastrointestinal illness and the age of the patient, plasmapheresis has **not been shown to be universally beneficial** and is generally not the first-line treatment.
Question 55: An 11-year-old boy with a history of attention deficit disorder presents to a general medicine clinic with leg pain. He is accompanied by his mother. He reports dull, throbbing, diffuse pain in his bilateral lower extremities. He reports that the pain feels deep in his muscles. He has awakened several times at night with the pain, and his symptoms tend to be better during the daylight hours. He denies fatigue, fever, or pain in his joints. On physical examination, his vital signs are stable, and he is afebrile. Physical examination reveals full range of motion in the hip and knee joints without pain. He has no joint effusions, erythema, or warmth. What is the next best step in management?
A. X-ray of the knees
B. Send ESR and CRP
C. Reassurance (Correct Answer)
D. MRI of the knees
E. Lower extremity venous ultrasound
Explanation: ***Reassurance***
- The patient's presentation is classic for **growing pains**, characterized by bilateral, diffuse, deep leg pain, often worse at night and improving with activity or during the day.
- The absence of fever, joint swelling, erythema, tenderness, or gait abnormalities, along with normal physical examination findings, supports this benign diagnosis.
*X-ray of the knees*
- This symptom complex is a **diagnosis of exclusion**; imaging studies like X-rays are typically normal and not indicated unless there are focal pain, limping, or other concerning signs.
- An X-ray would not show any abnormalities related to growing pains and would expose the child to unnecessary radiation.
*Send ESR and CRP*
- **Inflammatory markers** (ESR, CRP) are used to detect conditions like arthritis, osteomyelitis, or malignancy, which would cause systemic symptoms (e.g., fever, fatigue) or localized inflammatory signs.
- In growing pains, these markers are typically normal, and ordering them without other clinical indications is unnecessary.
*MRI of the knees*
- An MRI is highly sensitive for detecting bone and soft tissue pathologies but is generally not indicated for the typical presentation of growing pains.
- It would be considered if there were signs of **osteomyelitis**, **tumors**, or specific internal derangement of the joint, none of which are present here.
*Lower extremity venous ultrasound*
- This test is used to evaluate for **deep vein thrombosis (DVT)**, which typically presents with unilateral leg swelling, warmth, and tenderness.
- The patient's symptoms are bilateral, diffuse, and lack any signs of vascular compromise, making a venous ultrasound inappropriate.
Question 56: A 15-year-old boy is brought to the emergency department one hour after sustaining an injury during football practice. He collided head-on into another player while wearing a mouthguard and helmet. Immediately after the collision he was confused but able to use appropriate words. He opened his eyes spontaneously and followed commands. There was no loss of consciousness. He also had a headache with dizziness and nausea. He is no longer confused upon arrival. He feels well. Vital signs are within normal limits. He is fully alert and oriented. His speech is organized and he is able to perform tasks demonstrating full attention, memory, and balance. Neurological examination shows no abnormalities. There is mild tenderness to palpation over the crown of his head but no signs of skin break or fracture. Which of the following is the most appropriate next step?
A. Discharge without activity restrictions
B. Discharge and refrain from all physical activity for one week
C. Observe for 6 hours in the ED and refrain from contact sports for one week (Correct Answer)
D. Administer prophylactic levetiracetam and observe for 24 hours
E. Administer prophylactic phenytoin and observe for 24 hours
Explanation: ***Observe for 6 hours in the ED and refrain from contact sports for one week***
- This patient experienced a brief period of **confusion, headache, dizziness**, and **nausea** immediately after a head injury, which are symptoms consistent with a **mild traumatic brain injury (mTBI)** or **concussion**.
- Although his symptoms have resolved at presentation, observation in the ED for a few hours is prudent to ensure no delayed onset of more severe symptoms, and he should **refrain from contact sports** for at least one week as part of concussion management.
*Discharge without activity restrictions*
- Discharging without activity restrictions is unsafe given the initial symptoms of **confusion** and the potential for delayed symptom presentation or complications from a concussion.
- Concussion management requires a period of **physical and cognitive rest** to allow the brain to heal and prevent **second impact syndrome**.
*Discharge and refrain from all physical activity for one week*
- While refraining from all physical activity for one week is part of concussion management, discharging immediately without any observation period after initial neurological symptoms could be risky.
- An observation period allows for monitoring of any **worsening neurological signs** or symptoms that might indicate a more serious injury.
*Administer prophylactic levetiracetam and observe for 24 hours*
- **Prophylactic anticonvulsants** like levetiracetam are typically not recommended for routine management of **mild traumatic brain injury** or concussion.
- Their use is generally reserved for patients with more severe injuries, evolving conditions, or those who have had **seizures post-trauma**.
*Administer prophylactic phenytoin and observe for 24 hours*
- Similar to levetiracetam, **phenytoin** is an anticonvulsant and its prophylactic use is not indicated for **mild head injuries** or concussions.
- Anticonvulsant prophylaxis is associated with potential side effects and is reserved for specific high-risk scenarios, such as **severe TBI** or **penetrating head trauma**.
Question 57: A 3-year-old boy is brought to your pediatrics office by his parents for a well-child checkup. The parents are Amish and this is the first time their child has seen a doctor. His medical history is unknown, and he was born at 39 weeks gestation. His temperature is 98.3°F (36.8°C), blood pressure is 97/58 mmHg, pulse is 90/min, respirations are 23/min, and oxygen saturation is 99% on room air. The child is in the corner stacking blocks. He does not look the physician in the eye nor answer your questions. He continually tries to return to the blocks and becomes very upset when you move the blocks back to their storage space. The parents state that the child has not begun to speak and often exhibits similar behaviors with toy blocks he has at home. On occasion, they have observed him biting his elbows. Which of the following is the best next step in management?
A. Risperidone
B. Restructuring of the home environment
C. Fluoxetine
D. Hearing exam
E. Educating the parents about autism spectrum disorder (Correct Answer)
Explanation: ***Educating the parents about autism spectrum disorder***
- The child exhibits several **red flags for autism spectrum disorder (ASD)**, including **lack of eye contact, delayed speech, repetitive behaviors** (stacking blocks, becoming upset when routine is disrupted), and **self-injurious behavior** (biting elbows).
- Since this is the child's **first medical visit**, the parents are unaware of these concerns. The physician's first step should be to **educate the parents** about ASD to initiate further evaluation and early intervention.
- While a **formal diagnosis** requires more extensive evaluation (including developmental screening tools like M-CHAT-R and comprehensive assessment), educating the parents is crucial for obtaining their consent and cooperation for subsequent steps, which would include referral to a developmental specialist and early intervention services.
*Risperidone*
- **Risperidone** is an atypical antipsychotic medication sometimes used to manage severe **irritability** or **aggressiveness** in children with ASD, but it is not a first-line treatment for initial diagnosis or typical symptoms.
- Administering medication without a formal diagnosis, comprehensive behavioral management plan, and parental understanding is premature and inappropriate.
*Restructuring of the home environment*
- While **environmental modifications** can be beneficial for children with ASD, suggesting this as the first step without a clear diagnosis or parental understanding of specific needs is insufficient.
- The priority is to establish a diagnosis through proper evaluation and then tailor interventions, which may include home modifications in conjunction with other therapies like applied behavior analysis (ABA).
*Fluoxetine*
- **Fluoxetine** is a selective serotonin reuptake inhibitor (SSRI) used for anxiety, depression, and obsessive-compulsive disorder. It may be used in ASD to address **comorbid anxiety** or **repetitive behaviors**, but it is not a primary diagnostic tool or initial treatment.
- Like risperidone, prescribing medication without a proper diagnosis and understanding of the child's specific psychiatric needs is not the appropriate first step.
*Hearing exam*
- Although **hearing impairment** can cause **delayed speech** and affect social interaction, the child's other symptoms, such as **lack of eye contact, repetitive behaviors, and self-injurious actions**, are not typical of isolated hearing loss.
- While a hearing exam might be part of a comprehensive developmental workup later (as hearing and vision screening are standard in evaluating developmental delays), addressing the more pervasive signs suggestive of ASD takes precedence in the initial discussion with parents.
Question 58: A 6-year-old boy is brought to the physician because of right hip pain that started that afternoon. His mother reports that he has also been limping since the pain developed. He says that the pain worsens when he moves or walks. He participated in a dance recital yesterday, but his mother believes that he was not injured at the time. He was born at term and has been healthy except for an episode of nasal congestion and mild cough 10 days ago. His mother has rheumatoid arthritis and his grandmother has osteoporosis. He is at the 50th percentile for height and 50th percentile for weight. His temperature is 37.5°C (99.6°F), pulse is 105/min, respirations are 16/min, and blood pressure is 90/78 mm Hg. His right hip is slightly abducted and externally rotated. Examination shows no tenderness, warmth, or erythema. He is able to bear weight. The remainder of the examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 12.3 g/dL, a leukocyte count of 8,500/mm3, and an erythrocyte sedimentation rate of 12 mm/h. Ultrasound of the right hip shows increased fluid within the joint. X-ray of the hips shows no abnormalities. Which of the following is the most likely diagnosis?
A. Transient synovitis (Correct Answer)
B. Osteomyelitis
C. Slipped capital femoral epiphysis
D. Developmental dysplasia of the hip
E. Legg-Calve-Perthes disease
Explanation: ***Transient synovitis***
- This is the most likely diagnosis given the **recent viral illness**, acute onset of hip pain and limp, and **normal inflammatory markers** (WBC, ESR). Ultrasound showing **increased joint fluid** further supports this benign, self-limiting condition.
- The hip being held in **abduction and external rotation** is a common compensatory posture to maximize joint space and minimize pain in transient synovitis.
*Osteomyelitis*
- This would typically present with **fever**, significant systemic symptoms, and **elevated inflammatory markers** (ESR, CRP), which are absent here.
- Imaging might show bone changes, and the child would likely be **unable to bear weight** due to severe pain.
*Slipped capital femoral epiphysis*
- SCFE typically affects **adolescents** (obese males) and presents with chronic, progressive pain.
- X-rays would show a **displacement of the femoral head** from the femoral neck, which is not noted in this case.
*Developmental dysplasia of the hip*
- This is a condition usually diagnosed in **infancy or early childhood** through screening and clinical examination (e.g., Ortolani and Barlow maneuvers), often requiring early intervention.
- It would not typically present acutely in a 6-year-old with a recent viral prodrome and normal X-rays.
*Legg-Calve-Perthes disease*
- This condition involves **avascular necrosis of the femoral head** and typically presents in children between **4 and 8 years old** with a **chronic limp** and hip pain, often worsening over weeks to months.
- X-rays would show characteristic changes in the femoral head (e.g., fragmentation, flattening), which are absent in this case.
Question 59: A 5-week-old male infant is brought to the physician by his mother because of a 4-day history of recurrent nonbilious vomiting after feeding. He was born at 36 weeks' gestation via spontaneous vaginal delivery. Vital signs are within normal limits. Physical examination shows a 2-cm epigastric mass. Further diagnostic evaluation of this patient is most likely to show which of the following?
A. Dilated colon segment on abdominal x-ray
B. Elongated and thickened pylorus on abdominal ultrasound (Correct Answer)
C. Double bubble sign on abdominal x-ray
D. High serum 17-hydroxyprogesterone concentration
E. Corkscrew sign on upper gastrointestinal contrast series
Explanation: ***Elongated and thickened pylorus on abdominal ultrasound***
- The classic presentation of **hypertrophic pyloric stenosis** includes **nonbilious projectile vomiting** in an infant, often with an **epigastric olive-shaped mass**.
- **Abdominal ultrasound** is the diagnostic study of choice for pyloric stenosis and will reveal a **thickened and elongated pylorus**.
*Dilated colon segment on abdominal x-ray*
- This finding is more consistent with **Hirschsprung disease**, which typically presents with **constipation**, **abdominal distention**, and **failure to pass meconium**, not recurrent nonbilious vomiting.
- The clinical picture provided points away from a distal bowel obstruction.
*Double bubble sign on abdominal x-ray*
- The **double bubble sign** on an abdominal x-ray is characteristic of a **duodenal obstruction**, such as **duodenal atresia** or **annular pancreas**, and usually presents with **bilious vomiting** shortly after birth.
- The described vomiting is nonbilious, making this less likely.
*High serum 17-hydroxyprogesterone concentration*
- A high serum **17-hydroxyprogesterone** concentration is indicative of **congenital adrenal hyperplasia (CAH)**, which can present with **salt-wasting crises** and **vomiting** but typically involves **electrolyte abnormalities** and hormonal symptoms, not an epigastric mass.
- The nonbilious vomiting and palpable mass are not typical for CAH.
*Corkscrew sign on upper gastrointestinal contrast series*
- The **corkscrew sign** on an upper GI series is pathognomonic for **midgut volvulus**, which presents with **bilious vomiting**, **abdominal pain**, and signs of **peritonitis** or **sepsis**.
- The vomiting in this case is explicitly stated as nonbilious, ruling out malrotation with volvulus.
Question 60: An otherwise healthy 10-day-old boy is brought to the physician by his parents because of progressively enlarging breasts bilaterally for the last 4 days. The parents report that they have sometimes noticed a discharge of small quantities of a white liquid from the left breast since yesterday. During pregnancy, the mother was diagnosed with hypothyroidism and was treated with L-thyroxine. The patient's maternal grandmother died of breast cancer. The patient currently weighs 3100-g (6.8-lb) and is 51 cm (20 in) in length. Vital signs are within normal limits. Examination shows symmetrically enlarged, nontender breasts, with bilaterally inverted nipples. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?
A. Breast biopsy
B. Reassurance (Correct Answer)
C. Mammography
D. Chromosomal analysis
E. Serum gonadotropin measurement
Explanation: ***Reassurance***
- Neonatal breast enlargement and galactorrhea (**"witch's milk"**) are common, benign findings caused by **maternal hormones** (estrogen and prolactin) transferred across the placenta during pregnancy.
- This condition is typically self-limiting and resolves spontaneously within a few weeks as maternal hormones clear from the infant's system, requiring no intervention.
*Breast biopsy*
- A breast biopsy is an **invasive procedure** that is not indicated for a benign, self-limiting condition like neonatal gynecomastia and galactorrhea.
- This procedure carries risks of **infection, scarring**, and potential emotional distress for parents, and should be reserved for suspicious lesions in older children or adults.
*Mammography*
- Mammography involves **radiation exposure** and is not an appropriate diagnostic tool for a newborn with physiological breast enlargement.
- Its utility is primarily in evaluating breast tissue in **adults** for potential malignancy or other structural abnormalities.
*Chromosomal analysis*
- Chromosomal analysis is used to diagnose **genetic conditions** (e.g., Klinefelter syndrome) and is not indicated for isolated, transient breast enlargement and galactorrhea in an otherwise healthy neonate.
- This investigation would be considered if there were **other dysmorphic features**, developmental delays, or persistent endocrine abnormalities.
*Serum gonadotropin measurement*
- Measuring serum gonadotropin levels (LH, FSH) is generally used to evaluate **precocious puberty** or **hypogonadism** in older children or adolescents.
- In a newborn with physiological breast enlargement due to maternal hormones, these levels would likely be within a normal range for age or transiently elevated without indicating underlying pathology.
