Approach To Abdominal Mass

Question 1

What age group is most commonly affected by cystic mesoblastic nephroma?

Answer 1

• <6 months

Question 2

What age group is most commonly affected by hepatoblastoma?

Answer 2

6-18 months

Question 3

What age group is most commonly affected by neuroblastoma?

Answer 3

1-2 years

Question 4

What age group is most commonly affected by nephroblastoma?

Answer 4

2-3 years (rare <6 months or >8 years)

Question 5

What age group is most commonly affected by rhabdomyosarcoma?

Answer 5

3-5 years

Question 6

What age group is most commonly affected by fibrolamellar hepatocellular carcinoma?

Answer 6

Teenagers

Question 7

What antenatal condition requires follow-up postnatal ultrasound?

Answer 7

Hydronephrosis

Question 8

When should postnatal ultrasound be performed for hydronephrosis?

Answer 8

About 2 weeks postnatally

Question 9

Why should ultrasound be deferred if there is physiological oliguria in the first 72 hours after birth?

Answer 9

• It might cause a false negative follow-up renal ultrasound

Question 10

What condition should be considered with oligohydramnios?

Answer 10

Possible renal pathology

Question 11

What condition should be considered with polyhydramnios?

Answer 11

Possible bowel obstruction

Question 12

What are the features of sepsis to look for in a general examination of a child with an abdominal mass?

Answer 12

Signs of infection: fever, tachycardia, hypotension

Question 13

What are the signs of bowel obstruction in a child with an abdominal mass?

Answer 13

• Visible stomach bubble/bowel loops
• Generalized abdominal distension
• Cramp-like, coming-and-going pain

Question 14

What signs suggest urinary tract obstruction in a child with an abdominal mass?

Answer 14

Palpable bladder

Question 15

What constitutional non-specific symptoms of malignancy should be looked for?

Answer 15

• Weight loss
• Lymphadenopathy
• Pallor
• Lethargy

Question 16

What skin signs might suggest neuroblastoma metastases?

Answer 16

• “Blueberry muffin” spots
• “Panda bear eyes”

Question 17

What skin signs might suggest Peutz-Jegher’s syndrome?

Answer 17

Mucosal pigmentation (peri-oral & axillary freckling)

Question 18

What condition may be suggested by Peutz-Jegher’s syndrome skin signs?

Answer 18

Intestinal hamartomatous polyps, potentially leading to intussusception

Question 19

What should be considered with pyrexia in a child with an abdominal mass?

Answer 19

• Infection (if high-grade)
• Hematological malignancy (if low-grade)

Question 20

How common is hypertension in children with nephroblastoma and neuroblastoma?

Answer 20

Hypertension may occur in up to 80% of children with nephroblastoma
• More common with neuroblastoma, and can cause a hypertensive crisis

Question 21

What are the important characteristics to describe a mass in children?

Answer 21

• Size
• Shape and contour (smooth, round, septated, irregular edges, or nodular surface)
• Consistency (cystic, solid, pulsatile, conformable, or succussion splash suggesting gastric outlet obstruction)
• Mobility (tethered to organ/retroperitoneum, or free-floating like an auto-amputated ovarian cyst or small bowel duplication cyst)
• Anatomical relations (e.g., fixed central solid mass suggests neuroblastoma, lateral mass suggests nephroblastoma)

Question 22

How can the presence of a nasogastric tube or urinary catheter help assess a mass?

Answer 22

They may relieve distension or make the mass easier to palpate

Question 23

When should a digital rectal exam be considered?

Answer 23

• If there is a pelvic mass or symptoms of constipation/bowel obstruction
• To exclude presacral masses (e.g., teratoma, myelomeningocele, dermoid cyst)

Question 24

What should be checked during a perineal exam?

Answer 24

• Normal anal position
• Bulging imperforate hymen
• Presacral mass

Question 25

What should be checked on a urine dipstick for abdominal/flank and pelvic masses?

Answer 25

• Hematuria (suggestive of nephroblastoma) • Urinary tract infection (UTI) screening • Proteinuria (suggestive of renal disease)

Question 26

What laboratory tests should be performed for a child with an abdominal mass?

Answer 26

• Full blood count (look for anemia, low platelets, high white blood cell count, or high platelet count) • Baseline serum urea, creatinine, & electrolytes (especially if vomiting or signs of bowel obstruction) • Liver function tests (if jaundice or pancreatic pathology suspected)

Question 27

When are tumor markers useful in children with abdominal masses?

Answer 27

After imaging, certain tumor markers can help establish the diagnosis and track treatment response

Question 28

What are non-specific markers of increased cell turnover that suggest malignancy?

Answer 28

• Ferritin • Uric acid • LDH

Question 29

What tumor markers are useful for liver tumors and teratomas?

Answer 29

• Alpha-fetoprotein (AFP) • Beta-HCG

Question 30

What markers are useful for adrenal neuroblastoma or pheochromocytoma?

Answer 30

Urinary catecholamines (homovanillic acid, vanillylmandelic acid)

Question 31

What tumor marker is useful for ovarian tumors?

Answer 31

Beta-HCG

Question 32

What tumor markers are useful for testicular tumors?

Answer 32

• AFP • LDH

Question 33

What is the gold standard for the initial investigation of a mass in children?

Answer 33

Ultrasound

Question 34

What is the significance of the “tram-track” appearance in ultrasound?

Answer 34

Pathognomonic for a duplication cyst (hyperechoic mucosa outlining both sides of the muscularis wall)

Question 35

How can Doppler imaging be useful in ultrasound for abdominal masses?

Answer 35

Helps assess the degree of vascular invasion (e.g., inferior vena cava patency in nephroblastoma)

Question 36

When is abdominal x-ray useful in children with abdominal masses?

Answer 36

• If there is clinical suspicion of bowel obstruction (e.g., worm bolus obstruction, level of bowel obstruction) • To look for free air indicating the need for urgent surgical exploration

Question 37

What conditions can be identified on abdominal x-ray?

Answer 37

• Calcification in teratoma or neuroblastoma • Meconium pseudocyst • Renal or biliary stones secondary to urinary tract or biliary tree obstruction

Question 38

When is MRI used for abdominal masses in children

Answer 38

For further anatomical definition of a mass, especially to plan surgical resectability

Question 39

Why is abdominal CT scan largely avoided in children?

Answer 39

Due to the risks of ionizing radiation

Question 40

When is CT scan used in the assessment of abdominal masses?

Answer 40

To assess for pulmonary metastatic disease

Question 41

When is a biopsy performed in children with abdominal masses?

Answer 41

• After radiological definition of the mass • Biopsy may be image-guided (e.g., ultrasound) • Fine-needle aspiration, trucut/core-needle biopsy, or open/laparoscopic-assisted surgical biopsy may be required

Question 42

When is a bone marrow biopsy performed in children with abdominal masses?

Answer 42

To stage the tumor

Question 43

When should a referral be made for a possible malignancy?

Answer 43

• Urgently, to a tertiary center for further special investigation without delay • Always discuss with the referral center