Abdominal Calcifications

Michael Nasser, MD

DIFFERENTIAL DIAGNOSIS

Common

Nephrolithiasis
Cholelithiasis
Hepatic and Splenic Granulomas
Neuroblastoma
Hepatoblastoma
Teratoma (Ovarian)
Appendicolith

Less Common

Remote Adrenal Hemorrhage
Meconium Peritonitis

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Age of patient
Location of calcification
Morphology of calcifications: Coarse, punctate, or curvilinear

Helpful Clues for Common Diagnoses

Nephrolithiasis
- Conventional radiographs show punctate or coarse calcification that projects over
  - Renal shadow
  - Course of ureters
  - Expected location of bladder
- Renal calculi are echogenic with posterior shadowing on ultrasound
  - Color Doppler may be used to look for “twinkling” artifact or “comet tail” artifact posterior to small renal stones
Cholelithiasis
- ˜ 30% of gallstones are detectable by plain film
- Look for calcification projecting over medial aspect of hepatic silhouette on conventional radiographs
- US is preferred modality for evaluation
  - Gallstones are echogenic with posterior shadowing
Hepatic and Splenic Granulomas
- Multiple, punctate, round, or ovoid-shaped calcifications projecting over spleen &/or liver on plain film
- Appear as multiple, punctate, echogenic foci on ultrasound that may or may not have posterior shadowing
Neuroblastoma
- Can arise anywhere along sympathetic chain from skull base to pelvis
- Median age at diagnosis is 2 years old
- Involvement of adrenal glands and extraadrenal retroperitoneum make up more than 60% of cases
- Conventional radiographic findings
  - Paraspinal soft tissue mass
  - 30% will have associated calcifications
  - May have lytic, sclerotic, or mixed metastatic bone lesions
- CT findings
  - Soft tissue mass with heterogeneous attenuation (necrosis &/or hemorrhage)
  - Associated calcifications in up to 85% of cases
  - Engulfs adjacent vascular structures, such as celiac and superior mesenteric artery
  - Metastasis most common to liver & bone
  - Bone metastasis may be lytic, sclerotic, or mixed pattern
  - Look for involvement of neuroforamina
- MR findings: Best for detecting intraspinal extension of tumor
Hepatoblastoma
- Majority occur in children < 3 years old
- Painless abdominal mass
- Elevated α-fetoprotein levels
- Conventional radiographic findings
  - Large, soft tissue mass in right upper quadrant of abdomen
  - May displace bowel
  - Roughly 1/2 will have visible calcifications, usually coarse
- CT findings
  - Usually large at presentation
  - Well-defined lesion
  - > 60% located in right lobe of liver
  - Heterogeneous in attenuation due to necrosis and hemorrhage
  - Heterogeneous enhancement
  - Roughly 50% have coarse calcifications
  - CT of chest is performed for metastatic workup
Teratoma (Ovarian)
- Conventional radiographic findings
  - Punctate or coarse calcifications projecting over pelvis
  - May see associated “teeth” within pelvis
  - Mass effect upon adjacent structures
- Ultrasound findings
  - Heterogeneous echogenicity
  - Solid and cystic components
  - Fat and hair are echogenic
  - Calcifications are echogenic with posterior shadowing
  - May contain fat-fluid levels
  - Ovarian torsion may be a complication
- CT findings
  - Solid and cystic components
  - May have fluid levels
  - May contain fat
  - May contain coarse calcifications
  - May be bilateral in up to 15% of cases
Appendicolith
- 10-15% of acute appendicitis associated with appendicolith
  - Appendicolith may be round or oval-shaped
- Usually in right lower abdomen/pelvis
- May be in right upper abdomen in retrocecal appendix
- Conventional radiographic findings
  - Appendicolith (10-15%)
  - Air-fluid levels localized to right lower abdomen
  - Splinting (levocurvature of lower spine)
- CT findings
  - Appendicolith
  - Appendiceal diameter > 6 mm
  - Fluid-filled appendix with enhancement of appendiceal wall
  - Periappendiceal soft tissue infiltration
  - Look for abscess and extraluminal appendicolith with perforation

Helpful Clues for Less Common Diagnoses

Remote Adrenal Hemorrhage
- Resolving adrenal hemorrhage may calcify
- Secondary to any stress in perinatal period
- Bilateral in 10% of cases
- Punctate calcification may be seen on conventional radiographs projecting over suprarenal region
- Noncontrast abdominal CT to confirm intra-adrenal location
- Ultrasound with Doppler helpful to show lack of flow vs. flow in neuroblastoma
Meconium Peritonitis
- Sterile chemical reaction resulting from bowel perforation in utero
- 1 in 35,000 live births
- Conventional radiographic findings
  - Diffuse calcification
  - Sometimes pseudocyst formation (peripheral calcifications)
  - May displace bowel
- Ultrasound findings
  - May be diagnosed in utero during 2nd or 3rd trimester
  - Diffuse hyperechoic punctate echoes with or without acoustic shadowing
  - Especially along hepatic surface & in scrotum
  - May have ascites, polyhydramnios &/or bowel distention
  - If pseudocyst formation: Cystic heterogeneous mass with an irregular, calcified wall