AFP-Negative Hepatocellular Carcinoma

An US image of the liver shows a 2 cm solid nodule in a cirrhotic liver.

CT images of the liver in arterial and portovenous phases show arterial contrast enhancement with rapid washout of the nodule.

Facts: Serum AFP & Hepatocellular Carcinoma (HCC)

• First detection of AFP in serum of HCC patients in 1970s
• Currently, it is the only widely used serologic marker for diagnosing HCC. Additional useful markers in use are AFP-L3 and DCP
• Normal range 10-20 ng/mL
• AFP greater than 400 ng/mL generally considered a point of discriminating HCC from other chronic liver disease
• Problem: about 60% of patients with HCC have AFP below 200, up to 20% have normal AFP (AFP-negative HCC; AFP below 20)

Clinical Features of AFP-negative HCC

• Less likely to be hepatitis B positive
• Tend to have a lower level of ratio of serum glutamic oxaloacetic transaminase (AST)/pyruvic transaminase (ALT)

References:

1. Law WY. Hepatocellular Carcinoma, 2007.

2. Nomura F, Ohnishi K, Tanabe Y. Clinical features and prognosis of hepatocellular carcinoma with reference to serum alpha-fetoprotein levels. Analysis of 606 patients. Cancer 1989;64:1700-1707.

Infected Second Branchial Cleft Cyst

Axial CT image of the neck in a 2-year-old boy shows a cystic lesion in the right neck anterior to the sternocleidomastoid muscle, lateral to the carotid space. There is wall enhancement and nearby fascial thickening and subcutaneous fat stranding.

Facts: Branchial Cleft Cyst

• Type II = most common (92-99% of all branchial cleft cysts)
• Anywhere along anterior aspect of sternocleidomastoid muscle, lateral to carotid sheath to parapharyngeal space at the level of palatine tonsil
• CT: fluid density unless infected or hemorrhagic
• MRI: T1 hypointense, T2 hyperintense (unless infected or hemorrhagic)
• Can be associated with fistula or sinus tract

Other Things To Consider: Necrotic lymph node/metastasis, dermoid, abscess, laryngocele, ectopic thymic cyst

What Surgeons Want To Know

• Infection? May need surgery if at risk of septicemia or abscess
• Mass effects? Compression of esophagus, airways
• Neoplasm?
• Treatment of infected branchial cleft cyst is different from simple abscess. In the former, I&D alone is not adequate but the entire cyst and its tract must be removed to prevent recurrence. Therefore, it is important that accurate diagnosis is made preoperatively.

Our case: infected second branchial cleft cyst

Reference:

1. Bailey BJ, Calhoun KH. Atlas of Head & Neck Surgery-Otolaryngology, 2001.

2. Lin EC, Escott EJ, et al. Practical Differential Diagnosis for CT and MRI, 2008.

Intussusception Reduction

A "scout" radiograph before intussusception reduction procedure shows a soft tissue mass (arrows) in the right upper quadrant representing the intussusception. There is no free air.

Contrast enema for reduction shows the intussusception (arrows) in the right upper quadrant. It was successfully reduced.

Facts

• Image-guided liquid or air reduction of intussusception is the treatment of choice
• Contraindications for image-guided reduction = peritonitis, free intraperitoneal air due to perforation, in shock or sepsis
• Choice between air, liquid, contrast enema reduction of intussusception depends on radiologist experience and local preference/practice. Most radiologists prefer to use air and it is now generally accepted as the technique of choice
• Air pressure: between 80 and 120 mmHg
• Contrast: bag positioned approximately between 3 ft and 6 ft above the patient
• Reduction rate between 80% to 95%

Preparation for Reduction

• Notify the referring physician and surgeon
• Patient must be stable, well-hydrated and has no evidence of peritonitis
• IV line in place
• A large-bore needle at hand (if you use air reduction)

Complications

• Perforation rates with air enema less than 1%
• Recurrence 10% of cases

Reference:

1. Daldrup-Link HE, Gooding CA. Essentials of Pediatric Radiology: A Multimodality Approach, 2010.

2. Hodler J, Von Schulthess GK, Zollikofer CL. Diseases of the Abdomen and Pelvis 2010-2013: Diagnostic Imaging and Interventional Techniques, 2010.

Intussusception: Ultrasound

A longitudinal US image shows a "pseudokidney" sign of intussusception (arrows). Arrowheads point to enlarged mesenteric lymph nodes within the intussusceptum.

A transverse US image shows a "target" sign with a hypoechoic ring of the intussuscepiens surrouning the central echogenic area of intussusceptum. Arrowheads point to enlarged nodes.

Facts

• A segment of bowel (intussusceptum) prolapses into a more distal bowel segment (intussuscepiens)
• Most frequently seen in the first two years of life but can be seen up to 4 years. If older child has intussusception, looks for a lead point such as polyp, Meckel diverticulum, lymphoma, duplication cyst.
• Classic triad: colicky pain, vomiting and bloody (red currant jelly) stools (seen in less than 25% of cases)
• X-ray is positive in only 50% of cases, and is not reliable in diagnosing this condition

Ultrasound Findings

• Modality of choice to diagnose intussusception
• "Target" sign = hypoechoic ring with an echogenic center on transverse US image
• "Pseudokidney" sign = hypoechoic bowell wall extending along a hyperechoic mucosa
• Helpful in searching for a lead point. US can provide a specific diagnosis in one-third of these cases.

Reference:

1. Daldrup-Link HE, Gooding CA. Essentials of Pediatric Radiology: A Multimodality Approach, 2010.

2. Hodler J, Von Schulthess GK, Zollikofer CL. Diseases of the Abdomen and Pelvis 2010-2013: Diagnostic Imaging and Interventional Techniques, 2010.

Tension Pneumothorax

Chest radiograph shows a very large left pneumothorax (stars) causing mass effect to the mediastinum (shifting, arrows), deep costophrenic sulcus and collapsed left lung.

Facts

• One-way valve effect causing continuous air collection within pleural space resulting in collapse of the lung on the affected side and compression of opposite lung
• Poor lung compliance and increased airway pressure leads to ineffective gas exchange
• Mass effect on mediastinal structures cause decreased venous return and decreased cardiac output
• Symptoms and signs: chest pain, dyspnea, respiratory distress, tachypnea, dyspnea, cyanosis, elevated jugular venous pressure, absent breath sounds, tracheal deviation and hemodynamic compromise
• This is a clinical diagnosis and confirmation with radiography is not recommended. Needle decompression should be immediately performed

Imaging

• Again, this is a clinical diagnosis. Yet imaging may be performed and shows large pneumothorax, mediastinal shifting, flat hemidiaphragm

Reference:

Greenberg MI. Greenberg's Text-atlas of Emergency Medicine, 2005.