Sentinel Lymph Node Detection in Contralateral Axilla at Initial Presentation of a Breast Cancer Patient: Case Report

Area of Science:

• Oncology
• Surgical Pathology
• Medical Imaging

Background:

• The primary lymphatic drainage pathway for breast cancer is typically the ipsilateral axilla.
• Extra-axillary lymphatic drainage, such as to the internal mammary chain, can occur.
• Contralateral axillary drainage in untreated breast cancer patients is exceptionally rare.

Purpose of the Study:

• To describe a unique case of untreated breast cancer with contralateral axillary lymphatic drainage.
• To evaluate the utility of preoperative lymphoscintigraphy in identifying unusual lymphatic spread patterns.
• To assess the clinical significance of contralateral axillary metastasis in primary staging and patient management.

Main Methods:

• A case study of an untreated right breast retroareolar carcinoma.
• Preoperative lymphoscintigraphy was utilized to detect lymphatic drainage patterns.
• Sentinel lymph node (SLN) biopsy with frozen section examination and subsequent ipsilateral and contralateral axillary dissection were performed.

Main Results:

• Lymphoscintigraphy revealed contralateral axillary drainage.
• The SLN from the contralateral axilla showed micrometastasis, leading to contralateral axillary dissection.
• Postoperative pathology confirmed invasive ductal carcinoma metastasis in 17/22 ipsilateral axillary nodes, but only micrometastasis in the contralateral SLN, with other contralateral nodes being nonmetastatic.

Conclusions:

• Contralateral axillary drainage, though rare, can occur in untreated breast cancer.
• Preoperative lymphoscintigraphy is valuable for identifying atypical lymphatic spread.
• Detecting contralateral axillary metastasis during primary staging significantly impacts patient management strategies.