Laparoscopic fenestration of a neonatally detected hepatic mesenchymal hamartoma.

We report a case of hepatic mesenchymal hamartoma that was detected neonatally and successfully treated by laparoscopic fenestration. A baby girl was referred to our hospital 9 days after birth with a cystic lesion in her liver. Screening abdominal ultrasonography revealed a sonolucent lesion measuring 65 x 43 x 40 mm in the right lobe of the liver with a small solid area. Magnetic resonance imaging depicted the lesion as hyperintense on both T1- and T2-weighted images with no enhancement. A laparoscopic biopsy and fenestration of the lesion was performed. Histologic examination of the cyst wall led to a diagnosis of hepatic mesenchymal hamartoma. The postoperative course was uneventful and the patient is doing well at 4 years' follow-up, with no recurrence.