Synchronous presentation of invasive ductal breast carcinoma metastasis and ovarian granulosa cell tumor with literature review

Synchronous tumors involving the ovary are rare, particularly the coexistence of an ovarian granulosa cell tumor (GCT) and a metastatic ductal breast carcinoma within the same adnexa. While GCTs represent only 1–2% of all ovarian neoplasms, ovarian metastases from breast cancer account for up to 40% of secondary ovarian tumors, with a known predilection for invasive lobular subtypes. The synchronous occurrence of metastatic ductal carcinoma and a primary GCT remains exceptionally uncommon. We report the case of a 45-year-old woman referred because of with a Luminal B invasive ductal carcinoma of the breast, initially staged T3N1M0. She underwent neoadjuvant chemotherapy, radical mastectomy with axillary lymph node dissection, and adjuvant radiotherapy. A laparoscopic bilateral salpingo-oophorectomy was subsequently performed for hormonal suppression. Histopathological analysis revealed the unexpected coexistence of two distinct tumors within the same adnexal specimen: (1) an ovarian and tubal metastasis from the previously diagnosed breast ductal carcinoma, and (2) an adult-type granulosa cell tumor of the ovary. Immunohistochemistry confirmed the dual origin of the lesions. The postoperative course was uneventful, and systemic imaging showed no other metastatic sites. A multidisciplinary team recommended close surveillance. This case highlights the rare synchronous presentation of two histologically distinct neoplasms metastatic ductal breast carcinoma and a primary granulosa cell tumor within the same anatomical site. It underscores the importance of thorough histological evaluation in patients with a history of breast cancer undergoing therapeutic oophorectomy, even when ovaries appear macroscopically normal. We report an exceptionally rare case of synchronous ovarian involvement by metastatic ductal breast carcinoma and adult-type granulosa cell tumor within the same adnexa. Ovarian metastasis from ductal breast carcinoma coexisting with a granulosa cell tumor is exceedingly uncommon and poorly documented in the literature. Immunohistochemical analysis was essential to distinguish the dual tumor origin and establish the correct diagnosis. This case emphasizes the need for meticulous histopathological evaluation of adnexal specimens in breast cancer patients undergoing prophylactic oophorectomy. Awareness of such rare synchronous presentations is crucial to avoid diagnostic pitfalls and to guide appropriate multidisciplinary management.