Prepubertal-type testicular teratoma with a neuroblastoma component in an infant: a case report

Prepubertal-type testicular teratomas generally show benign biological behavior and may contain mature or immature neural tissue. A peripheral neuroblastoma component, however, is exceptionally rare and can be difficult to distinguish from conventional immature neuroepithelium. We report a boy aged 4 months and 25 days with a right testicular teratoma treated by testis-sparing excision. Histopathologic examination identified minute, multifocal neuroblastoma components within a prepubertal-type testicular teratoma. The lesional cells showed diffuse strong nuclear expression of paired-like homeobox 2B (PHOX2B). Fluorescence in situ hybridization (FISH) showed no MYCN amplification, telomerase reverse transcriptase (TERT) rearrangement, 1p36 deletion, or 11q23 deletion. Imaging revealed no extratesticular primary tumor or metastatic disease, and no recurrence or metastasis was observed during approximately 14 months of follow-up. This case expands the clinicopathologic spectrum of prepubertal-type testicular teratoma and provides additional morphologic, immunophenotypic, and molecular characterization of this rare presentation in infancy.