Immunohistochemical localization of nanog and Oct4 in stem cell compartments of human sacrococcygeal teratomas

Aims: To study the range of differentiation and presence of cells positive for stem cell markers in 20 sacrococcygeal teratomas (SCTs) which were consecutively operated on between 1990 and 2000 in the Department of Paediatric Surgery in Tubingen, Germany. Methods and results: Preserved paraffin-embedded material was re-evaluated. In addition to tissues of various organs, caudal organ structures not described before were identified, such as colon with pancreas originating from colonic crypts, Fallopian tube and vaginal epithelia. The derivation of the latter was confirmed by Mullerian duct specific CA125 and CA19-9 antibodies. The expression of stem cell markers was studied with antibodies against nanog, Oct4, SSEA-4, nestin and subtype M3 muscarinic receptors. Cells positive for these markers were encountered in immature end buds and capillary sprouts, and as single cells in neural tissue, gonadal structures, hairs and in the stem cell niches of differentiated epithelia. Conclusions: Our data indicate that SCTs of the newborn arise from remnants of the epiblast-like tail bud blastema and demonstrate that they contain cells positive for embryonic stem cell markers and may represent a novel source for human embryonic stem cells.