Lobular carcinoma in ectopic axillary breast tissue

Area of Science:

• Embryology and Human Anatomy
• Oncology
• Pathology

Background:

• Accessory mammary tissue, or supernumerary breasts, arise from the embryonic milk line (axilla to groin).
• It occurs in 2-6% of women and requires inclusion in the differential diagnosis for masses along the milk line.
• Accessory breast tissue undergoes similar physiological and pathological changes as normal breast tissue.

Observation:

• Numerous benign and malignant masses have been reported in accessory mammary tissue.
• Common pathologies include fibroadenomas, phyllodes tumors, and invasive mucinous adenocarcinoma.
• Invasive ductal carcinoma is the predominant malignancy, mirroring pectoral breast tissue.

Findings:

• This report details a rare case of lobular carcinoma originating in axillary ectopic breast tissue.
• While previously documented, lobular carcinoma in this location remains an uncommon finding.
• The case underscores the potential for diverse pathologies within accessory mammary glands.

Implications:

• Accurate diagnosis of masses in the axilla and along the milk line is crucial.
• Awareness of rare pathologies like lobular carcinoma in ectopic breast tissue is important for clinicians.
• Further research may elucidate the specific risk factors and behaviors of malignancies in accessory mammary tissue.