Mesenchymal hamartoma of liver: magnetic resonance imaging and histopathologic correlation

To describe the imaging features of hepatic mesenchymal hamartoma with emphasis on magnetic resonance imaging (MRI) compared to histopathologic results.

Spin-echo sequence(SE),fast spin-echo sequence(FSE) were performed in 12 children (7 males,5 females) with mesenchymal hamartoma of the liver (MHL), aged 1.2 months to 12 years;( mean age, 6.3 years) axial, saggital, coronary plain imaging with an Elscint 2.0T MR equipment. Their main symptoms were abdominal mass (5 cases), enlarged liver (8 cases), abdominal pain (1 case) and anemia (2 cases), and negative alphafetoprotein. Dynamic enhancement examination was added in 2 cases.

Six cases had single mass type of MHL, in which 3 cases had solid masses showing slight low-signal-intensity in T1WI, and irregular high-signal-intensity in T2WI, 1 case had a cystic-solid mixed mass showing several border-clear cysts in a solid mass, 2 cases had cystic masses with multi-septa. Five cases had diffuse and multifocal lesions type of MHL with its signal intensity being similar to that of the solid mass. One case had a combined diffuse and single cystic mass. In the early dynamic enhancement examination, the lesions were slightly circum-enhanced , and the center was enhanced in the later scan images. Inner hepatic vessels were compressed in 5 cases, vena cava and abdominal aortae were compressed in 3 cases. Pathological findings included fiber hyperplasia, hyaline degeneration, biliary duct hyperplasia, lobule-like array.

MR imaging is a better way to differentiate and diagnose MHL. MHL may be recognized by its characteristic occurrence in infancy and MR imaging features.