Liver Mesenchymal Hamartoma

**Semantic type:** Neoplastic Process

**Definition:** A multicystic mesenchymal tumor that arises from the liver during fetal development. It is the third most common pediatric liver tumor following hepatoblastoma and infantile hemangioma. Cytogenetic and molecular studies have revealed the presence of chromosomal rearrangements involving chromosome 19q13.4 or androgenetic-biparental mosaicism. These findings support the evidence that it is a neoplastic process and not only a developmental process. Clinically, it usually presents as an abdominal mass associated with abdominal distention. Morphologically, it consists of hypocellular fibromyxoid stroma and bland spindle cell proliferation. It generally has a benign clinical course. Following resection, the prognosis is good.

**Synonyms:** - HMH - Hepatic Mesenchymal Hamartoma - Liver MH - Mesenchymal Hamartoma of Liver - Mesenchymal Hamartoma of the Liver