What happened, in summary

A woman in her early 60s had noticed nodules in her left breast for about 5 years before one enlarged rapidly in early 2024. Imaging showed a suspicious 3.7 cm breast mass, and a biopsy confirmed breast cancer. The tumor was estrogen-receptor positive and HER2-negative.

Before chemotherapy, chest imaging also showed that she had situs inversus totalis, a rare congenital condition in which the internal organs are arranged as a mirror image of the usual anatomy. Because this changed the normal position of major veins, her team carefully planned the placement of the implanted venous port needed for treatment.

She then received chemotherapy before surgery. The breast mass remained stable rather than shrinking. She subsequently underwent a modified radical mastectomy of the left breast. Final pathology showed invasive micropapillary carcinoma, with cancer found in 15 of 32 removed lymph nodes. After treatment, the tumor remained estrogen-receptor positive and was HER2-negative.

Her treatment required extra planning because of the mirror-image position of her internal organs and major veins, but chemotherapy and surgery were completed as planned.