RESUMEN
BACKGROUND: Adenosarcomas are rare tumors usually derived from the endometrium. About 50 cases of adenosarcomas of the ovary have been reported. The relationship between adenosarcoma and CA125 has not been described. The authors present a case of adenosarcoma with elevated CA125 because of the unusual presentation of this pathology and also because elevation of the CA125 antigen has not been reported in the literature. CLINICAL CASE: A 42-year-old woman presented for consultation for incidental right ovarian tumor and CA125 of 1100 U/mL. Histology revealed a homologous Müllerian adenosarcoma of the right ovary with sarcomatous overgrowth. CA125 decreased to 16 U/mL after surgery. Sixteen months post-surgery, the patient is disease free and with normal CA125. DISCUSSION: Ovarian adenosarcomas are more aggressive than adenosarcomas of the uterus. Because of the embryological origin, ovarian adenosarcomas are able to produce CA125 antigen, especially in the presence of sarcomatous overgrowth. With these facts, CA125 antigen may be useful as a prognostic factor because it may represent an indirect marker of sarcomatous overgrowth. CONCLUSIONS: CA125 may be useful for follow-up of ovarian adenosarcomas. Elevated CA125 antigen in adenosarcomas of the ovary may be indicative of sarcomatous overgrowth and poor prognosis.