A laborer's younger child is brought to the OPD with a swollen belly and dull face. He has been fed rice water (rice milk) in his diet mostly. On investigations, the child is found to have low serum protein and low albumin. What is the probable diagnosis?
Q2
A 12-year-old boy presents with symptoms of headaches, visual disturbances, and growth retardation. An MRI scan is performed, and the image provided shows a cystic mass with both solid and calcified components in the suprasellar region, extending into the third ventricle. Based on the clinical presentation and MRI findings, what is the most likely diagnosis?
Q3
A baby was playing unattended and suddenly developed respiratory distress. Based on the X-ray provided, where is the foreign object most likely located?
Q4
A 10-year-old male presents with generalized edema. His cholesterol level is $238 \mathrm{mg} / \mathrm{dl}$, urine protein is $3+$, and stool microscopy shows fat in the stool. What is the most likely diagnosis?
Q5
In a child with a height-for-age Z-score of less than -2 standard deviations (SD), what is the most likely cause?
Q6
A child presents with rachitic changes in the limbs that are not responding to Vitamin D supplementation. Investigations reveal the following results:
- Calcium: $9.5 \mathrm{mg} / \mathrm{dl}$
- Phosphorus: $1.6 \mathrm{mg} / \mathrm{dl}$
- Alkaline phosphatase (ALP): 814 IU
- Serum PTH: $24.2 \mathrm{pg} / \mathrm{ml}$
- Serum electrolytes, creatinine, and blood gases: Normal.
What is the most likely diagnosis?
Q7
An anganwadi teacher measures the weight and height of a 4-year-old child and finds that the child's height-for-age is below the normal percentile. What does this finding indicate?
Q8
A 16-month-old child weighing 8 kg is assessed using a growth chart. The child's weight falls between the median (standard) and minus 2 standard deviations ( -2 SD ). What should be the next step in the management of this child?
Q9
A 4-month-old African-American infant is brought to the pediatrician for a well-baby check up. He was born at term through a normal vaginal delivery and has been well since. His 4-year old brother has sickle-cell disease. He is exclusively breastfed and receives vitamin D supplements. His immunizations are up-to-date. He appears healthy. His length is at the 70th percentile and weight is at the 75th percentile. Cardiopulmonary examination is normal. His mother has heard reports of sudden infant death syndrome (SIDS) being common in his age group and would like to hear more information about it. Which of the following is the most important recommendation to prevent this condition?
Q10
A 6-year-old boy is brought to the emergency department with a mild fever for the past week. He has also had generalized weakness and fatigue for the past month. He has been complaining of diffuse pain in his legs and arms. He has a history of Down syndrome with surgical repair of a congenital atrial septal defect as an infant. His temperature is 38.0° C (100.4° F), pulse is 85/min, respirations are 16/min, and blood pressure is 90/60 mm Hg. He has enlarged cervical lymph nodes bilaterally that are nontender to palpation. He is uncooperative for the rest of the examination. Laboratory studies show:
Hemoglobin 10.2 g/dL
Hematocrit 30.0%
Leukocyte count 50,000/mm3
Platelet count 20,000/mm3
Serum
Sodium 136 mEq/L
Potassium 4.7 mEq/L
Chloride 102 mEq/L
Bicarbonate 25 mEq/L
Urea nitrogen 18 mg/dL
Creatinine 1.1 mg/dL
Total bilirubin 0.9 mg/dL
AST 30 U/L
ALT 46 U/L
Which of the following is most likely to confirm the diagnosis?
Growth/Development US Medical PG Practice Questions and MCQs
Question 1: A laborer's younger child is brought to the OPD with a swollen belly and dull face. He has been fed rice water (rice milk) in his diet mostly. On investigations, the child is found to have low serum protein and low albumin. What is the probable diagnosis?
A. Kwashiorkor (Correct Answer)
B. Kawasaki disease
C. Marasmus
D. Indian childhood cirrhosis
E. Nephrotic syndrome
Explanation: ***Kwashiorkor***
- The symptoms of a **swollen belly** (due to **edema** from low albumin), **dull face**, and a diet primarily of **rice water** (low in protein) are classic signs of Kwashiorkor.
- Kwashiorkor is a form of severe protein-energy malnutrition characterized by **protein deficiency** that is greater than the calorie deficit, leading to **hypoalbuminemia** and fluid retention.
- The **dietary history** of rice water (carbohydrate-rich but protein-poor) is the key distinguishing feature.
*Kawasaki disease*
- This is an **acute vasculitis** primarily affecting young children, presenting with fever, rash, conjunctivitis, mouth changes, and lymphadenopathy.
- It does not involve a swollen belly or dull face as primary symptoms, nor is it linked to dietary protein deficiency.
*Marasmus*
- Marasmus is a form of severe malnutrition characterized by an **overall deficiency of calories** and nutrients, resulting in severe **wasting** of muscle and fat.
- While it involves low weight and energy deficit, the prominent **edema** (swollen belly) seen in this case points away from marasmus.
*Indian childhood cirrhosis*
- This is a rare, **fatal liver disease** in young children, often characterized by jaundice, hepatosplenomegaly, and liver failure.
- It is not primarily caused by protein deficiency and its symptoms are distinct from the presentation described.
*Nephrotic syndrome*
- While nephrotic syndrome also presents with **hypoalbuminemia and edema**, it would show **proteinuria** (>3.5 g/day), hyperlipidemia, and lipiduria on urinalysis.
- The **dietary history** and absence of urinary findings distinguish kwashiorkor from nephrotic syndrome.
Question 2: A 12-year-old boy presents with symptoms of headaches, visual disturbances, and growth retardation. An MRI scan is performed, and the image provided shows a cystic mass with both solid and calcified components in the suprasellar region, extending into the third ventricle. Based on the clinical presentation and MRI findings, what is the most likely diagnosis?
A. Craniopharyngioma (Correct Answer)
B. Germinoma
C. Meningioma
D. Pituitary adenoma
E. Optic glioma
Explanation: ***Craniopharyngioma***
- This tumor is classically described as having **cystic** and **solid components** with **calcification**, which is evident in the provided MRI image. Its location in the **suprasellar region** and extension into the **third ventricle** are also typical.
- The clinical presentation of **headaches**, **visual disturbances** (due to compression of the optic chiasm), and **growth retardation** (due to hypothalamic-pituitary axis dysfunction) in a 12-year-old boy is highly suggestive of a craniopharyngioma, which commonly affects children and young adults.
*Germinoma*
- While germinomas can occur in the suprasellar region and cause similar endocrine and visual symptoms, they typically appear as **solid, homogeneously enhancing masses** on MRI and are less commonly cystic and calcified.
- They are more common in adolescence and are highly sensitive to radiation therapy, but their imaging characteristics differ from the described lesion.
*Meningioma*
- Meningiomas typically arise from the **arachnoid mater** and are usually **solid, extra-axial masses** that often have a **dural tail sign** on MRI.
- They are less common in children, and while they can calcify, their characteristic imaging features (extra-axial, dural attachment) are not consistent with the described suprasellar, intra-axial cystic mass.
*Pituitary adenoma*
- Pituitary adenomas originate from the **pituitary gland** and are usually located within the sella turcica, extending superiorly. While they can be cystic, **calcification is rare**, and they are more commonly solid and homogeneously enhancing.
- Although they can cause visual disturbances and hormonal imbalances, the prominent cystic-solid appearance with calcification and clear suprasellar origin extending into the third ventricle makes craniopharyngioma a more likely diagnosis in this age group and imaging.
*Optic glioma*
- Optic gliomas (pilocytic astrocytomas) are common **suprasellar tumors in children**, especially those with neurofibromatosis type 1, and can cause visual disturbances and endocrine dysfunction.
- However, they typically appear as **solid, fusiform masses** involving the optic nerve or chiasm with **homogeneous enhancement** and rarely show the characteristic cystic-solid architecture with prominent calcification seen in craniopharyngiomas.
Question 3: A baby was playing unattended and suddenly developed respiratory distress. Based on the X-ray provided, where is the foreign object most likely located?
A. Trachea
B. Gastrointestinal tract
C. Esophagus (Correct Answer)
D. Below diaphragm
E. Right main bronchus
Explanation: ***Esophagus***
- The frontal X-ray shows a **coin-shaped foreign body** that is oriented in the **coronal plane** (flat face visible), which is characteristic of an object lodged in the esophagus.
- The foreign body is located in the **upper mediastinum**, directly in the known anatomical path of the esophagus, causing respiratory distress due to **extrinsic compression** of the trachea or aspiration.
*Trachea*
- Foreign bodies in the trachea, especially flat objects like coins, typically orient themselves in the **sagittal plane** (on edge) due to the C-shaped cartilaginous rings.
- While tracheal foreign bodies can cause respiratory distress, the orientation on the image is inconsistent with a tracheal location.
*Right main bronchus*
- The **right main bronchus** is the most common site for aspirated foreign bodies in children due to its wider diameter and more vertical orientation.
- However, foreign bodies in the bronchus would typically show air trapping or atelectasis on chest X-ray, and the location and orientation of this object in the upper mediastinum are not consistent with bronchial placement.
*Gastrointestinal tract*
- The foreign body is located in the **chest cavity**, well above the stomach and intestines.
- If a foreign body reaches the gastrointestinal tract, it would typically be beyond the esophagus and would not usually cause acute respiratory distress.
*Below diaphragm*
- The diaphragm separates the chest cavity from the abdominal cavity. The foreign body is clearly visible within the **chest cavity**, high up in the mediastinum.
- A foreign body below the diaphragm in the gastrointestinal tract would not result in the appearance or the acute respiratory distress described without other symptoms.
Question 4: A 10-year-old male presents with generalized edema. His cholesterol level is $238 \mathrm{mg} / \mathrm{dl}$, urine protein is $3+$, and stool microscopy shows fat in the stool. What is the most likely diagnosis?
A. Nephritic syndrome
B. Goodpasture syndrome
C. Nephrotic syndrome (Correct Answer)
D. Urine infection
E. Minimal change disease
Explanation: ***Nephrotic syndrome***
- **Nephrotic syndrome** is characterized by **generalized edema**, **massive proteinuria** (3+ in urine protein), and **hyperlipidemia** (elevated cholesterol).
- **Fat in the stool** (steatorrhea) can be an associated finding due to malabsorption or metabolic derangements, though not a primary diagnostic criterion for nephrotic syndrome.
- This is the **syndrome** that encompasses the entire clinical presentation.
*Minimal change disease*
- **Minimal change disease** is the **most common etiology** of nephrotic syndrome in children (accounting for ~80% of cases in this age group).
- While this child likely has minimal change disease as the underlying cause, the question asks for the **syndrome/diagnosis** based on the clinical presentation, which is **nephrotic syndrome**.
- Minimal change disease is the pathologic diagnosis that would be confirmed on **renal biopsy**.
*Nephritic syndrome*
- **Nephritic syndrome** typically presents with **hematuria**, **hypertension**, **azotemia**, and mild to moderate proteinuria, rather than massive proteinuria and generalized edema.
- It is characterized by inflammation of the glomeruli, often leading to a decrease in **glomerular filtration rate (GFR)**.
*Goodpasture syndrome*
- **Goodpasture syndrome** is an autoimmune disease characterized by **rapidly progressive glomerulonephritis** and **pulmonary hemorrhage**.
- While it causes renal involvement, its distinct feature is the presence of **anti-glomerular basement membrane (GBM) antibodies**, and the clinical picture does not align with the given symptoms.
*Urine infection*
- A **urine infection** (urinary tract infection) typically presents with dysuria, frequency, urgency, and sometimes fever, with positive urine cultures and pyuria.
- It does not explain the presence of **generalized edema**, **hyperlipidemia**, or **massive proteinuria**.
Question 5: In a child with a height-for-age Z-score of less than -2 standard deviations (SD), what is the most likely cause?
A. Chronic malnutrition (Correct Answer)
B. No malnutrition
C. Acute malnutrition
D. Recent infection
E. Genetic short stature
Explanation: ***Chronic malnutrition***
- A **height-for-age Z-score of less than -2 SD** is a key indicator for **stunting**, which is primarily caused by prolonged periods of **inadequate nutrition** and/or recurrent infections.
- This reflects **long-term nutritional deprivation** impacting linear growth, rather than recent or acute issues.
*No malnutrition*
- A Z-score below -2 SD for height-for-age is a critical threshold indicating **significant growth faltering**, making the absence of malnutrition highly unlikely.
- This measurement directly reflects that the child's height is significantly below the expected range for their age, signifying a nutritional problem.
*Acute malnutrition*
- **Acute malnutrition** is typically assessed by **weight-for-height Z-score** (wasting) or Mid-Upper Arm Circumference (MUAC).
- While acute malnutrition impairs growth, a low height-for-age Z-score specifically points to a problem of **longer duration (chronic)** rather than immediate weight loss.
*Recent infection*
- While **recent infections** can lead to temporary weight loss and affect appetite, they typically do not cause a **pronounced and sustained reduction in height-for-age** (stunting) unless they are recurrent or chronic, contributing to overall chronic malnutrition.
- A single, recent infection is more likely to impact **weight-for-height** acutely.
*Genetic short stature*
- While **genetic factors** can influence height, a height-for-age Z-score of less than -2 SD in the context of population-based assessment typically indicates **pathological growth failure** due to chronic malnutrition.
- Genetic short stature typically maintains **proportional growth** with consistent growth velocity, whereas stunting shows **growth faltering** over time.
Question 6: A child presents with rachitic changes in the limbs that are not responding to Vitamin D supplementation. Investigations reveal the following results:
- Calcium: $9.5 \mathrm{mg} / \mathrm{dl}$
- Phosphorus: $1.6 \mathrm{mg} / \mathrm{dl}$
- Alkaline phosphatase (ALP): 814 IU
- Serum PTH: $24.2 \mathrm{pg} / \mathrm{ml}$
- Serum electrolytes, creatinine, and blood gases: Normal.
What is the most likely diagnosis?
A. Hypophosphatemic rickets (Correct Answer)
B. Vitamin D-dependent rickets type 2
C. Vitamin D-dependent rickets type 1
D. Chronic renal failure
E. Vitamin D deficiency rickets
Explanation: ***Hypophosphatemic rickets***
- The combination of **rachitic changes** not responding to Vitamin D, **low serum phosphorus (1.6 mg/dl)**, and **normal calcium and PTH levels** strongly points to hypophosphatemic rickets, a condition characterized by impaired renal phosphate reabsorption.
- The **elevated alkaline phosphatase** indicates increased bone turnover as the body tries to mineralize bone despite phosphate deficiency.
*Vitamin D-dependent rickets type 2*
- This condition involves resistance to **1,25-dihydroxyvitamin D**, leading to **hypocalcemia** and elevated PTH, none of which are present here.
- It would also typically show an inadequate response to Vitamin D, but the primary biochemical derangement is different.
*Vitamin D-dependent rickets type 1*
- This type is caused by a defect in **1-alpha-hydroxylase**, leading to an inability to convert 25-hydroxyvitamin D to its active form, resulting in **hypocalcemia** and elevated PTH, which are not observed.
- It would also show a poor response to standard Vitamin D supplementation.
*Vitamin D deficiency rickets*
- This is the most common form of rickets caused by inadequate Vitamin D intake or synthesis, presenting with **hypocalcemia**, **elevated PTH**, and **low phosphorus**.
- However, it typically responds well to Vitamin D supplementation, unlike the presentation here, and would show elevated PTH levels.
*Chronic renal failure*
- Chronic renal failure would present with **elevated creatinine**, and typically leads to **secondary hyperparathyroidism** (elevated PTH), **hyperphosphatemia**, and metabolic acidosis, none of which are suggested by the provided lab results.
- The serum electrolytes, creatinine, and blood gases are explicitly stated as normal.
Question 7: An anganwadi teacher measures the weight and height of a 4-year-old child and finds that the child's height-for-age is below the normal percentile. What does this finding indicate?
A. No malnutrition
B. Acute malnutrition
C. Chronic malnutrition (Correct Answer)
D. Recent malnutrition
E. Acute and chronic malnutrition
Explanation: ***Chronic malnutrition***
- **Height-for-age** is an indicator used to assess **long-term nutritional status**, meaning a deficit suggests chronic nutritional problems.
- A child with low height-for-age is considered **stunted**, which is a hallmark of chronic malnutrition resulting from prolonged inadequate nutrient intake.
- Since the question only mentions **height-for-age being low** without mentioning weight-for-height, this indicates **chronic malnutrition alone** (stunting).
*No malnutrition*
- A finding of **height below the normal percentile** is a direct indicator of poor growth, which contradicts the concept of no malnutrition.
- This measurement tool is specifically designed to identify nutritional deficiencies.
*Acute malnutrition*
- **Acute malnutrition** is typically assessed using **weight-for-height** or **mid-upper arm circumference (MUAC)**, indicating recent and rapid weight loss.
- A child with acute malnutrition is often referred to as **wasted**, which is different from being stunted.
*Recent malnutrition*
- While all malnutrition has a "recent" onset at some point, **height-for-age** reflects a cumulative effect over time, not just recent deprivation.
- For assessing recent nutritional issues, **weight-for-height** or **weight-for-age** would be more appropriate indicators.
*Acute and chronic malnutrition*
- This condition (also called **wasted and stunted**) occurs when a child has both **low weight-for-height** (acute/wasting) AND **low height-for-age** (chronic/stunting).
- The question states only that **height-for-age is below normal**, with no mention of weight-for-height status, so we cannot diagnose acute malnutrition component.
- This would require assessment of both anthropometric indicators.
Question 8: A 16-month-old child weighing 8 kg is assessed using a growth chart. The child's weight falls between the median (standard) and minus 2 standard deviations ( -2 SD ). What should be the next step in the management of this child?
A. Identify mild malnutrition and initiate homebased nutritional support.
B. Recognize moderate malnutrition and provide feeding education to the mother.
C. Reassure the mother that the child is within normal nutritional status. (Correct Answer)
D. Diagnose severe malnutrition and refer to a Nutritional Rehabilitation center
E. Initiate therapeutic feeding with ready-to-use therapeutic food (RUTF).
Explanation: ***Reassure the mother that the child is within normal nutritional status.***
- According to WHO growth standards, a child's weight between the **median and -2 SD** falls within the **normal range**.
- Weight-for-age between +2 SD and -2 SD is considered **normal nutritional status**.
- The appropriate management is to **reassure the parents**, provide anticipatory guidance on nutrition, and continue **routine growth monitoring**.
- No specific nutritional intervention is required unless there are other clinical concerns.
*Identify mild malnutrition and initiate home-based nutritional support.*
- **Mild malnutrition (underweight)** is defined as weight-for-age between **-2 SD and -3 SD**, not between median and -2 SD.
- This child's weight is **above -2 SD**, placing them in the normal range, so this intervention is not indicated.
*Recognize moderate malnutrition and provide feeding education to the mother.*
- **Moderate malnutrition** is indicated when a child's weight falls between **-2 SD and -3 SD**.
- This child's weight is **above -2 SD** and therefore does not meet criteria for moderate malnutrition.
*Diagnose severe malnutrition and refer to a Nutritional Rehabilitation center.*
- **Severe acute malnutrition (SAM)** is diagnosed when weight-for-height is **below -3 SD**, or when there is visible severe wasting or bilateral pitting edema.
- This child's weight is well above the threshold for severe malnutrition.
*Initiate therapeutic feeding with ready-to-use therapeutic food (RUTF).*
- **RUTF** is reserved for children with **severe acute malnutrition** requiring therapeutic nutritional rehabilitation.
- This child has normal nutritional status and does not require therapeutic feeding products.
Question 9: A 4-month-old African-American infant is brought to the pediatrician for a well-baby check up. He was born at term through a normal vaginal delivery and has been well since. His 4-year old brother has sickle-cell disease. He is exclusively breastfed and receives vitamin D supplements. His immunizations are up-to-date. He appears healthy. His length is at the 70th percentile and weight is at the 75th percentile. Cardiopulmonary examination is normal. His mother has heard reports of sudden infant death syndrome (SIDS) being common in his age group and would like to hear more information about it. Which of the following is the most important recommendation to prevent this condition?
A. Have the baby sleep in supine position (Correct Answer)
B. Use soft bedding and pillows for the baby
C. Make sure that no one smokes around the baby
D. Cardiorespiratory monitoring of the baby at home
E. Have the baby sleep with the parent
Explanation: ***Have the baby sleep in supine position***
- The "Back to Sleep" campaign significantly reduced **SIDS incidence** by advocating for placing infants on their backs for sleep.
- Sleeping in the **supine position** ensures an open airway and reduces the risk of suffocation or rebreathing exhaled air.
*Use soft bedding and pillows for the baby*
- **Soft bedding**, pillows, and bumpers increase the risk of suffocation and rebreathing exhaled air, which are risk factors for SIDS.
- The sleeping surface should be **firm and clear** of all soft objects for infant safety.
*Make sure that no one smokes around the baby*
- Exposure to **secondhand smoke** is a known risk factor for SIDS; however, it is not the most important immediate recommendation regarding sleep position.
- While crucial for overall infant health, addressing the **sleep environment** directly impacts airway safety.
*Cardiorespiratory monitoring of the baby at home*
- **Home cardiorespiratory monitoring** is generally reserved for infants at high risk for apnea or other specific medical conditions, not as a blanket recommendation for SIDS prevention in healthy infants.
- It is not a primary preventative measure for SIDS in the general population of healthy infants.
*Have the baby sleep with the parent*
- **Co-sleeping (bed-sharing)** with parents increases the risk of SIDS due to potential suffocation, entrapment, or overlaying by parents.
- The recommendation is for infants to **sleep in the same room** as the parents but in their own separate safe sleep space (crib or bassinet).
Question 10: A 6-year-old boy is brought to the emergency department with a mild fever for the past week. He has also had generalized weakness and fatigue for the past month. He has been complaining of diffuse pain in his legs and arms. He has a history of Down syndrome with surgical repair of a congenital atrial septal defect as an infant. His temperature is 38.0° C (100.4° F), pulse is 85/min, respirations are 16/min, and blood pressure is 90/60 mm Hg. He has enlarged cervical lymph nodes bilaterally that are nontender to palpation. He is uncooperative for the rest of the examination. Laboratory studies show:
Hemoglobin 10.2 g/dL
Hematocrit 30.0%
Leukocyte count 50,000/mm3
Platelet count 20,000/mm3
Serum
Sodium 136 mEq/L
Potassium 4.7 mEq/L
Chloride 102 mEq/L
Bicarbonate 25 mEq/L
Urea nitrogen 18 mg/dL
Creatinine 1.1 mg/dL
Total bilirubin 0.9 mg/dL
AST 30 U/L
ALT 46 U/L
Which of the following is most likely to confirm the diagnosis?
A. Bone marrow biopsy (Correct Answer)
B. Serum protein electrophoresis
C. Blood culture
D. Echocardiography
E. Monospot test
Explanation: ***Bone marrow biopsy***
- The patient's symptoms (fever, fatigue, diffuse bone pain, lymphadenopathy) combined with **marked leukocytosis (WBC 50,000/mm³), anemia, and severe thrombocytopenia** are highly suggestive of **acute leukemia**.
- Children with **Down syndrome have a 10-20 times increased risk** of developing acute leukemia, particularly acute lymphoblastic leukemia (ALL) and acute megakaryoblastic leukemia (AMKL).
- A **bone marrow biopsy** is the definitive diagnostic test for leukemia, as it allows for morphological, immunophenotypic, and cytogenetic analysis of bone marrow cells to confirm the diagnosis and classify the specific type of leukemia.
*Serum protein electrophoresis*
- This test is primarily used for diagnosing **plasma cell disorders** like multiple myeloma or monoclonal gammopathy, which are not suggested by the patient's presentation or laboratory findings.
- While leukemias can rarely present with abnormal protein production, it is not the initial or most appropriate diagnostic step for suspected leukemia.
*Blood culture*
- A blood culture is used to identify **bacterial or fungal infections** in the bloodstream. While the patient has a mild fever and could have an infection, the persistent symptoms (weeks to a month), generalized bone pain, and particularly the marked leukocytosis with severe thrombocytopenia and anemia are characteristic of hematologic malignancy rather than simple infection.
- Although ruling out infection may be important (especially in the context of potential neutropenia if blasts predominate), it would not confirm the underlying hematologic malignancy indicated by the lab results.
*Echocardiography*
- **Echocardiography** evaluates the structure and function of the heart. The patient has a history of repaired atrial septal defect, but there are no current cardiac symptoms or signs (e.g., murmurs, signs of heart failure) that necessitate an echocardiogram for the presenting complaints.
- This test would not help in diagnosing the suspected hematologic condition.
*Monospot test*
- The **Monospot test** is used to diagnose infectious mononucleosis, typically caused by the Epstein-Barr virus (EBV). While some symptoms (fever, fatigue, lymphadenopathy) can overlap, the marked leukocytosis (likely with circulating blasts), severe thrombocytopenia, and diffuse bone pain are not characteristic of mononucleosis.
- Infectious mononucleosis typically presents with **atypical lymphocytosis**, not the marked leukocytosis with severe thrombocytopenia seen in this case.
