Metastatic squamous cell carcinoma arising from mature teratoma of the ovary: Description of multi-modality treatment including incorporation of adjuvant immunotherapy and maintenance PARP inhibitor therapy

•Squamous cell carcinoma arising from mature teratoma of the ovary is a rare occurrence without clear agreement regarding optimal treatment.•Multimodality treatment should be considered, particularly for metastatic disease.•Maintenance therapy may be considered.