Focal nodular hyperplasiaBy mahyarHistory: An asymptomatic 22 Y/F , with incidental well-demarcated liver lesion in abdominal US Findings:
:: CT 1 ::CECT
:: MRI 1 ::MRI
:: MRI 2 ::MRI +Gd
:: X-Ray 1 ::Angiography
:: X-Ray 2 ::Angiography Discussion: Focal nodular hyperplasia (FNH) Benign tumor of liver caused by hyperplastic response to a localized vascular abnormality Best diagnostic clue: Brightly and homogeneously enhancing mass in arterial phase CT or MR with delayed enhancement of central scar Location: More common in right lobe, Right lobe to left lobe: 2:1 Usually subcapsular & rarely pedunculated Size: o Majority are smaller than 5 cm (85%), Mean diameter at time of diagnosis is 3 cm Key concepts: 2nd most common benign tumor of liver Benign congenital hamartomatous malformation Accounts for 8% of primary hepatic tumors in autopsy series Usually a solitary lesion (80%); multiple in 20% o Multiple FNHs associated with multiorgan vascular malformations and with certain brain neoplasms CT Findings: NECT: Isodense or hypodense to normal liver CECT: Hepatic arterial phase (HAP) scan Transient intense hyperdensity, o Portal venous phase (PVP) scan, Hypodense or isodense to normal liver Delayed scans: Mass: Isodense to liver Central scar: Hyperdense, Scar visible in 2/3rd of large, 1/3rd of small FNH MR Findings TlWI: Mass: Isointense to slightly hypointense Central scar: Hypointense T2WI: Mass: Slightly hyperintense to isointense Central scar: Hyperintense T1 C+: Arterial Phase: Hyperintense (homogeneous) Portal Venous: Isointense Delayed phase: Mass: Isointense Scar: Hyperintense Specific hepatobiliary MR contrast agents , T2WI with superparamagnetic iron oxide (SPIO) FNH shows decreased signal due to uptake of iron oxide particles by Kupffer cells within lesion Degree of signal loss in FNH is greater than other focal liver lesions (metastases, adenoma & HCC) Gadobenate dimeglumine (Gd-BOPTA) Bright homogeneous enhancement of FNH Prolonged enhancement of FNH on delayed scan (due to malformed bile ductules) Delayed scan: Significant enhancement of scar Differential diagnosis: Hepatic adenoma Cavernous hemangioma Fibrolamellar carcinoma Hepatocellular carcinoma Hypervascular metastasis Diagnosis confirmation: Surgery / Histo Category: Gastrointestinal Region / Organ: Abdomen-Liver Etiology: congenital References: Get more for Focal nodular hyperplasia Peer-reviewed resources Literature  More publications about Focal nodular hyperplasia Challenge yourself with the case quiz! |