Malignant transformation of mesenchymal hamartoma of the liver: Case report and review of the literature

Here the first case in the literature of both mesenchymal hamartoma and mal ignant mesenchymoma occurring in a 6-year-old male child, at different time s and at different sites in the liver, and also the possible malignant tran sformation of a mesenchymal hamartoma is reported. The tumor developed from a lesion in the right robe that was overlooked initially during a left lat eral segmentectomy at 18 months of age for a mesenchymal hamartoma. Maligna nt mesenchymoma is a rare and aggressive tumor. The origin of this tumor is not well understood. There has been no direct support to the hypothesis th at malignant mesenchymoma may be the malignant counterpart of mesenchymal h amartoma. The authors provide clinical and histopathologic evidence in our case that suggests the possibility of malignant mesenchymoma arising from a mesenchymal hamartoma. This case emphasizes the need for complete removal of mesenchymal hamartoma and the need for long-term follow-up to detect mul tifocal lesion or malignant transformation. Copyright (C) 1999 by W.B. Saun ders Company.