Current perspectives on diagnosis and management of primary and secondary breast endometriosis and potential risk of breast cancer

Table 1 Published, histopathologically confirmed cases of mammary endometriosis

Ref.	Age (years)	Location	Classification	Clinical presentation	Imaging findings	Histopathology/immunohistochemistry	Proposed pathogenesis	Outcome
Moloshok and Ivan'ko[15]	35	Subareolar breast parenchyma	Primary mammary endometriosis	Painful subareolar nodule, clinically interpreted as fibroadenoma	Not reported	Endometrial glands and stroma embedded in breast tissue with hemosiderin deposition	Lymphovascular dissemination	Complete remission after excision
McArthur et al[17]	35	Reconstructed breast (DIEP flap)	Iatrogenic mammary endometriosis	Painless breast lump 1-year post-reconstruction	Not specific	Endometrial-type glands and stroma within adipose tissue of transferred flap, focal hemorrhage	Iatrogenic transplantation from abdominal donor site	No recurrence after excision
Al-Wageeh et al[52]	16	Retroareolar breast parenchyma	Primary mammary endometriosis	Painful retroareolar swelling, initially suspected abscess	Poorly circumscribed cystic-solid lesion on ultrasound	Endometrial glands and stroma with hemosiderin-laden macrophages; stromal CD10(+), glandular ER/PR(+)	De novo mammary localization	No recurrence at 1-year follow-up
De la Riva-Morales et al[16]	49	Interface between DIEP flap and native breast	Iatrogenic mammary endometriosis	Firm breast nodule 1-year post-reconstruction	Mimicked fat necrosis	Well-formed endometrial glands and stroma with hemosiderin; PAX8(+), CD10(+), GATA3(-)	Iatrogenic implantation	Complete remission after excision
Reza et al[51]	24	1Skin between breasts (cutaneous)	Cutaneous endometriosis (non-mammary)	Painful swollen mass with periodical abscess discharge	Not specific fluid findings	Excision biopsy Endometrial glands and stroma with hemosiderin within skin	Lymphovascular dissemination	Excision

¹This case is included for anatomical comparison only and does not represent true mammary parenchymal involvement. Mammary cutaneous endometriosis represents a diagnostic challenge owing to its infrequent occurrence and its clinical presentation, which often resembles other breast disorders. Nonetheless, it is an established condition characterized by the presence of ectopic endometrial tissue within the skin of the breast, leading to cyclical symptomatology. DIEP: Deep inferior epigastric perforator; CD10: Cluster differentiation, antigen; PAX8: Pair boxed, antigen; GATA3: GATA binding protein 3, transcription factor; ER: Endoplasmatic reticulum; PR: Progesterone receptors.

Table 2 Immunohistochemical profile

Marker	Expected result	Diagnostic significance
CD10	Positive (stromal cells)	Sensitive marker of endometrial stroma. Useful when glands are scant
PAX8	Positive (glandular epithelium)	Confirms Mullerian epithelial origin
GATA3	Negative	Excludes breast epithelial origin
ER/PR	Often positive	Hormonal responsiveness, nonspecific within breast tissue

CD10: Cluster differentiation, antigen; PAX8: Pair boxed, antigen; GATA3: GATA binding protein 3, transcription factor; ER: Endoplasmatic reticulum; PR: Progesterone receptors.