Congenital neoplasms in cattle: A literature review and multi-institutional case series.

Congenital neoplasms are rare and sporadic in cattle and can cause losses due to abortions and perinatal or neonatal deaths. The etiopathogenesis of congenital tumors in bovine fetuses and neonates is largely unknown, and their diagnosis is often challenging. Here we review the literature on congenital tumors in cattle and report 11 additional cases diagnosed at veterinary diagnostic laboratories in Argentina, Uruguay, the United States, and the United Kingdom, namely 4 congenital lymphomas, 3 mesotheliomas, 2 adenomatoid tumors, 1 lymphangioma, and 1 ovarian sex cord-stromal tumor in bovine fetuses and/or neonatal calves. Lymphomas, mesotheliomas, melanomas, and mast cell tumors were reported most commonly in the literature.