Two types of small cell carcinoma of the ovary: Two typical case reports

•This report shows very rare cases of small cell carcinoma of the ovary, hypercalcemic type and pulmonary type.•Their chemo sensitivity is quite different. These two cases followed opposite clinical courses.•The first case (SCOHT) progressed rapidly, and showed resistance to chemotherapy and radiotherapy.•The second case (SCOPT) showed sensitivity to chemotherapy and radiotherapy although recurrence was repeated.