Case Report: Invasive micropapillary ductal breast carcinoma [version 1; peer review: 1 approved with reservations]

Background: Invasive micropapillary carcinoma (IMPC) of the breast is a rare variant of invasive ductal breast carcinoma (IDC), with most cases characterized by lymph node metastasis and lymphatic vascular invasion. It is a ductal breast cancer subtype with a very high risk of recurrence and therefore requires special attention from breast cancer physicians and radiologists. Case: We present a case of an IMPC that has been followed up for two years since diagnosis and management. Based on clinical breast examination, ultrasound, and mammography, the initial diagnosis was a suspicious mass that required further investigation. Radiological and histological findings informed the diagnosis of a highly suspicious lesion, which turned out to be IMPC. The patient underwent surgery, left mastectomy with nodal dissection. During the 24-month follow-up, ultrasound and mammography revealed no evidence of local recurrence or involvement of the contralateral breast. Conclusions: This case reveals that invasive micropapillary carcinoma is a distinct but poorly recognized variant and subtype of invasive ductal carcinoma.