Breast metastasis from endometrial clear cell carcinoma: A case report and review of the literature

Abstract

Metastasis to the breast from extra-mammary malignancies are rare, accounting for less than 1% of all breast cancers. Endometrial cancer, a common gynecological malignancy, often spreads to the pelvis, abdominal lymph nodes, peritoneum or the lungs. Endometrial metastasis to the breast is extremely rare, and while there have been isolated case reports of endometrial serous carcinoma with breast metastasis, it has not been reported in the case of clear cell carcinoma. We present a rare case of a 70 year old Chinese lady who had a metastatic endometrial clear cell carcinoma with metastasis to the breast, mimicking an inflammatory breast cancer clinically. We reviewed the current literature and describe the challenges in differentiating primary from metastatic breast lesions, as well as clinical, radiological and histopathological features that may help to differentiate the two. Tumour metastasis to the breast via lymphatic or hematogenous route can affect their radiological features: the former mimicking inflammatory breast cancer and the latter with features similar to benign breast lesions. Regardless, histological features with immunohistochemical staining is still the gold standard in diagnosing metastatic breast lesions and determining their tissue of origin. Breast metastases from extra-mammary malignancies are uncommon and it is even rarer for endometrial clear cell carcinoma to spread to the breast. Nonetheless, this case highlights the importance of keeping an open mind and engaging a multidisciplinary team for the care of complex patients.

Breast metastases from extra-mammary cancers: A report of 3 challenging cases and literature review

“…Breast metastases originating from extra-mammary tumors represent a rare occurrence that demands a multidisciplinary approach. Imaging assumes a pivotal role in both the detection and occasionally challenging characterization of these lesions [21] .…”

Dedifferentiated endometrial carcinoma metastasis to axillary lymph node: a case report

“…LN mets do occur with endometrial carcinoma. Metastatic tumor cells are usually carried to the LNs from the primary site via lymphatic trunks [ 13 ]. The pathway from a primary uterine carcinoma to anatomically appropriate LNs in the pelvis and related locoregional intraabdominal and inguinal LNs is initiated through invasion of peri- or intra-tumoral lymphatic capillaries and flow via lymphatic trunks, from where they enter the sentinel LN subcapsular sinus via afferent lymphatics penetrating the capsule of the LN.…”

“…Even more rare is the recently recognized dedifferentiated endometrial carcinoma, which tends to be more aggressive, diagnosed at a later stage, and noted to be resistant to conventional chemotherapies [ 12 ]. Several studies have reported deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H) in 46–73% of dedifferentiated endometrial carcinomas [ 13 ]. Of note, these dMMR carcinomas have been shown to express programmed cell death protein 1 (PD 1)/programmed cell death ligand 1 (PD-L1) at high rates [ 14 ].…”

“…To the best of our knowledge, there exists only eight cases reported in literature of endometrial carcinoma distant metastasis to the breast, which were of clear cell and serous cell histology and not dedifferentiated [ 13 ]. This case report presents a unique presentation of a rare subtype of endometrial carcinoma metastasizing to the axillary lymph node with a remarkable response to immunotherapy.…”