heterotopic breast epithelial inclusion of the heart

Although the heterotopic breast tissue on the skin along the milk line is well recognized, it has also been described to involve internal organs including the heart.

Synopsis

 heterotopic breast epithelial inclusion of the heart
 focally microcystic ductal/tubular structures lined by a biphasic pattern of cuboidal to columnar apical epithelial cells with an outer layer of flattened basal cells.

• These glandular structures are arranged in vaguely lobular and focally infiltrative patterns in the epicardium and interstitium.
• No architectural or cytologic atypia or mitotic or apoptotic figures.
• The apical epithelial cells are immunoreactive for pankeratin, cytokeratin (CK) 7, estrogen receptor, progesterone receptor, gross cystic disease fluid protein-15, and negative for CK20, calretinin, Wilms’ tumor suppressor gene (WT1), CD31, suggestive of mammary epithelial differentiation.
• The basal cells are immunoreactive for pankeratin, CK7, CK5/6, D2-40, smooth-muscle actin and focally S100, suggestive of myoepithelial differentiation.

References

 Heterotopic Breast Epithelial Inclusion of the Heart: Report of a Case. Sasaki K, Parwani AV, Demetris AJ, Sasatomi E. Am J Surg Pathol. 2010 Aug 16. PMID: 20717001