[Mullerian "inclusions" within an intramammary lymph node]

Area of Science:

• Pathology
• Radiology
• Gynecologic Oncology

Background:

• Mullerian inclusions are typically found in lymph nodes below the diaphragm.
• Intra-mammary lymph nodes are rarely affected by Mullerian inclusions.

Observation:

• A 63-year-old asymptomatic patient presented with microcalcifications in the right breast on mammography.
• These microcalcifications were associated with benign-appearing epithelial formations within an intra-mammary lymph node.
• Immunohistochemistry revealed estrogen receptor positivity and negativity for thyroglobulin, calretinin, and smooth muscle actin.

Findings:

• The study identified Mullerian inclusions within an intra-mammary lymph node, a supra-diaphragmatic location.
• The epithelial formations within the inclusions expressed estrogen receptors, suggesting a Mullerian origin.

Implications:

• This case highlights the possibility of Mullerian inclusions occurring in unusual locations like intra-mammary lymph nodes.
• The presence of Mullerian inclusions in the breast, though rare, may be associated with an increased risk of pelvic serous carcinoma.
• This finding underscores the importance of considering Mullerian pathology in supra-diaphragmatic lymph nodes, even in asymptomatic patients.