Mesenchymal hamartoma or embryonal sarcoma of the liver in childhood: a difficult diagnosis before complete surgical excision.

BACKGROUND: Clinical experience shows that the primary diagnosis of mesenchymal hamartoma (MHL) and embryonal sarcoma of the liver (ESL) recurrently is mistaken, leading to inadequate managements. We evaluated the accuracy of the primary diagnosis of those liver tumors, compared with the final histological diagnosis. METHODS: Records of 25 children (0-16 years, treated 01/1989-01/2013) with final diagnosis of MHL or ESL were analyzed. RESULTS: Final diagnosis was MHL in 18/25 children (10 solid-cystic, 2 cystic, 6 solid) and ESL in 7/25 (4 solid-cystic, 1 cystic, 2 solid). Only 3/7 ESL patients and 15/18 MHL patients fell into the "typical" age group. In 13/25 children primary diagnosis was based on imaging only. Overall, primary diagnosis was concordant with the final diagnosis in 17/25 patients. Of 99/25 biopsied cases, 4/9 biopsy results exposed the wrong final diagnosis; of cystic-solid masses 4/14 were mistaken, of cystic masses 1/3, of solid masses 3/8. CONCLUSION: Preoperative diagnosis of MHL and ESL is challenging because of atypical clinical presentation, misleading "typical" radiological findings, and difficult interpretation of biopsies. If feasible, complete surgical resection of, in particular, solid-cystic liver masses in the pediatric age group must be aimed for, to get a definitive, final diagnosis, followed by an adequate treatment strategy.