Clinical Significance of Renal Tissue in Neonatal Sacrococcygeal Teratoma: A Case Report With Review of Literature

: Congenital sacrococcygeal teratomas (SCTs) are rare tumors with highly variable prognosis, influenced by associated abnormalities and marked histological heterogeneity. SCTs may exhibit somatic renal differentiation, encompassing a wide spectrum of cytological and architectural features, for which accepted diagnostic criteria are lacking. This renders the distinction between immature nephrogenic tissue and true nephroblastoma particularly challenging. We report an illustrative neonatal case of SCT containing a minor nephroblastomatous component and conducted a systematic review to evaluate management and outcomes in newborns (≤28 days old) with renal tissue identified within SCTs. A comprehensive search of PubMed, Scopus, and Web of Science yielded 532 records, of which 16 studies met inclusion criteria. Including the present case, 19 newborns were analyzed. Renal tissue was described as immature or ectopic nephrogenic tissue in 15 cases (79%) and as overtly malignant, consistent with Wilms tumor, in 4 cases (21%). All patients underwent surgical resection, while chemotherapy (n = 5; 26.3%) and radiotherapy (n = 2; 10.5%) were less frequently administered. Median follow-up was 29.5 months (range: 4-154), with no cancer-related mortality. In the absence of standardized diagnostic criteria, renal differentiation within SCTs represents a diagnostic and therapeutic dilemma, supporting a cautious, multidisciplinary management approach.