¹Department of Pathology, Apollo Cancer Centre, Chennai, India, Presently in Delhi, Working at Max Super Specialty Hospital
²Department of Anesthesiology, All India Institute of Medical Sciences, NewDelhi, India

*Corresponding author:Babita Sodhi, Department of Pathology, Apollo Cancer Centre, Chennai, India, Presently in Delhi, Working at Max Super Specialty Hospital, India, E-mail Id: babitasodhi196@gmail.com

Article Information:Submission: 04/09/2024; Accepted: 27/09/2024; Published: 30/09/2024

Copyright: © 2024Sodhi B, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Ectopic Breast tissue (EBT) is a rare entity. It occurs due to the incomplete regression of the milk line which extends from axilla to groin and occurs commonest in axilla and rarest in vulva.EBT has the potential to turn malignant, thus the condition needs to be followed up including cytology if required. However, rarity of the condition frequently delays the diagnosis which can lead to morbidity and mortality in a patient. There is urgency of formulation of guidelines for management of such patients which should be addressed.
We report the youngest patient of healthy EBT from the Indian subcontinent in a 25-year-old woman and discuss review of literature.

Keywords:Ectopic Breast Tissue; Vulva; Estrogen Receptor; Progesterone Receptor; Immuno histochemistry

Ectopic breast tissue (EBT) is a rare entity with an incidence of 2-6% in women &1-3% in men, with women to men ratio of 2:1 [1]. It is a developmental anomaly due to incomplete regression of milk line and presents as residual breast tissue with or without nipple areolar complex in milk ridge line in addition to normal pectoral tissue. It can be solitary or multiple [2,3]. EBT in vulva, including benign and malignant pathology, are reported in literature in 129 patients in age group of 18-89 years [4], of which20 patients with healthy breast tissue in EBT is reported from 29-69 years. From the Indian subcontinent only 4 such patients are reported in women from 28-60 years. [5-8]. We report the youngest female patient of 25 years old of healthy breast tissue (HBT) in EBT from the Indian subcontinent and discuss review of literature, management dilemmas and urgency to formulate guidelines in such patients.

A 25-year-old pregnant lady reported with non-painful swelling on left side of vulva at eight month of gestation which progressively increased after delivery. A soft mobile mass of 3x2x1cm was palpated in the vulva. Excisional biopsy was done under local anesthesia. Cut surface revealed grey white and lobulated mass. Differential diagnosis of lipoma, Bartholin Cyst, and Hidradenitis Papilliferum was made. On histologic evaluation on staining with hematoxylin and eosin, lobules of healthy breast tissue with lactational changes were seen. Immunohistochemistry revealed estrogen receptor (ER) positive (ALL RED Score 8) (Figure 2 c-d) and focally positive for progesterone receptor (PR) (Figure 2e). [9] Diagnosis of EBT (Figure 2a) (Figure 2b) was made.

The present patient is the youngest reported patient (25 years)

old) of HBT of EBT in vulva from the Indian subcontinent. Previous literature reveals 126 patients of EBT of which HBT of EBT was reported in 20 patients in the age group from 29-69 years including, 4 such patients in age group of 28-60 years from the Indian subcontinent are reported. [4-8].

Primary milk line develops in human embryo at 6 week gestation and extends from axilla, through thoracic (pectoral, chest area), abdominal, inguinal, to pubic area, where it traverses bilaterally and atrophies by 9 wks of gestation except in chest where normal breast tissue develops. Incomplete regression of primary milk line gives rise to EBT anywhere in milk line and appears as smooth well circumscribed mass with/ without nipple and /or areola. EBT may not be clinically apparent unless it becomes site of pathological process or physiological changes. The commonest site of EBT is axilla, however it is reported in unusual sites like vulva, chest, face, ear, abdomen, inguinal region, perineum, perianal region, heart and foot.EBT on vulva is rarely reported and may present as an abscess, bartholin abscess, fibroadenoma, recurrent vulval Fibroadenoma, phyllodes tumors and atypical hyperplasia [10-16]. EBT in vagina was reported at a rare site of median episiotomy [17]. Extra vulval EBT was reported in infraclavicular chest wall, in perineal region of a gentleman,in inguinal region and as an enlarging abdominal mass [18-21]. Usually EBT occurs without nipple and/or nipple areolar complex. However, EBT with nipple areola in vulva with lactation from vulva and perianal mass is also reported including Indian subcontinent [22,23].

Lactational changes in EBT vulva& lactational adenoma of EBT have also been documented in literature [24,25]. Rarely, EBT may present outside ventrally placed milk ridge such as on the face or foot which can be explained by displacement or migration of milk ridge anlage [26]. Heterotopic breast type epithelial inclusion was seen in atrial tissue in surgically explanted native heart of 72-year-old transplant recipient [27]. EBT occurs commonly in reproductive age group, however rarely it’s reported in postmenopausal women [28]. The youngest reported patient of HBT of EBT of vulva was reported in an adolescent girl of 18 years [29]. In literature HBT in EBT vulva has been reported in 20 patients with 4 from Indian subcontinent [30-45]. The management of EBT is similar to a growth seen in healthy breast. Previously, patients of EBT which revealed fibroadenoma and HBT, local excision of EBT was done. [2, 3,5,7,8,30-43] [Table 1] as in the present patient. If EBT reveals carcinoma, then according to the stage of carcinoma, neoadjuvant chemotherapy maybe added.In a patient of EBT in infraclavicular area, cytology revealed invasive ductcarcinoma and patient was treated with chemotherapy and hormone therapy.

The differential diagnosis of EBT is lactational breast, Hidradenoma papilliferumor Bartholin Cyst. Lactational breast is diagnosed by Immunohistochemical (IHC) demonstration of ER and PRas in the present patient. Hidradenoma papilliferum is a well circumscribed mass lesion with papillary glandular epithelium with associated myoepithelial cells and a fibrovascular core forming true papillae. Bartholin cyst show epithelial lining as squamous, transitional or mucinous.

EBT is under same hormonal influences as normal breast and

undergoes same physiological and pathological changes as of normal breast and thus may transform to malignant variant. Most cases of EBT are benign however few malignant cases of EBT are also reported which includes papillomas, intraductal carcinoma, invasive ductalcarcinoma, metachronous vulval EBT adenocarcinoma, invasive lobular carcinoma and mucinous Adenocarcinoma [46-51]. Primary carcinoma should be differentiated from metastatic breast carcinoma by initial diagnosis by fine needle aspiration cytology and confirmation by histopathological examination [52,53]. Benign EBT may convert to malignant morphology.

The entity of HBT presenting as EBT in vulva is rare. However, it may convert to malignant variant anytime during the course of the lifespan of the patient. Thus, it is recommended that a treating physician on encountering any mass in vulva should bevigilant in its diagnosis including cytology and regular follow ups to rule out malignancy. The mass maybe removed if the patient desires so due to discomfort or cosmetic reasons as in the present patient. There are no guidelines in literature on management of HBT in EBT vulva and thus requires urgency to formulate guidelines on screening and follow up of EBT.

EBT should be suspected in any subcutaneous mass along milk line and should be regularly followed up due to its malignant potential. Due to scarcity of such patients in reported literature, every case of EBT should be reported and documented to formulate guidelines.