Ectopic breast cancer: a case report

Abstract

An ectopic breast may be found at any location other than its normal place, from the axilla to the vulva. Cysts, adenofibromas and rarely carcinomas have been seen in ectopic breasts. In this case report, we present a patient with ectopic breast cancer. The patient had a hard and dark brownish ectopic breast just on the left arcus costarum. Tru-cut biopsy revealed it as “invasive lobular cancer”. Left ectopic mastectomy and level I-II axillary dissection were performed and then chemotherapy+radiotherapy+endocrine therapy treatment was commenced. During follow up, the patient is doing well; in spite of R1 resection, she has no evidence of local recurrences or distant metastases.

Keywords: Ectopic breast cancer, accessory breast, ectopic mastectomy

Introduction

Ectopic breast can be seen anywhere on the milk line from the axilla to the vulva, as a result of non-complete normal embryological development of the breast bud. Familial transmission might be seen and breast cancer development has also been rarely reported. In this article we present a case in whom surgery was performed for an ectopic breast cancer.

Case Presentation

Forty-one -year-old female patient presented complaining of a mass under her left breast, dark brownish discoloration and a tense feeling around this area for the last 7-8 months, on August 2010. Her bilateral breast and right axilla examinations were normal, a 2x2 cm hard, mobile lymph node was observed in the left axilla. The left ectopic breast was located anterior to the costal arch, its surrounding skin showed dark brownish discoloration, and a firm subcutaneous mass of 2x2 cm was palpable (Figure 1).

Figure 1. Pre-operative view of the breast

Figure 2. a,b. Post-operative view of the breast

The patient was referred to Medical Oncology and Radiation Oncology departments. She received radiotherapy (RT), chemotherapy (CT) and endocrine therapy (ET), and is still being followed-up with no local recurrence and distant metastases.

Discussion

Ectopic (accessory) breast can be seen anywhere on the milk line from the axilla to the vulva, as a result of non-complete normal embryological development of the breast bud [1]. It is more common than amastia. It has gained attention in history beginning from the early ages, the statue of Ephesian Diana is symbolic with her 20 ectopic breasts [2]. Ectopic breast can be seen in three ways. 1-Numerous nipples 2- Numerous nipple-areola complex 3- Numerous breast.

The rate of ectopic breast is 1-4% in Caucasians. This abnormality is more common in the Far East. It can be seen in both sexes. There is familial transmission. Its incidence is reported as 1.68% in Japanese men, and as 5.19% in Japanese women [2, 3]. These abnormal structures are most often located in the axilla, followed by the area immediately inferior to the normal breast. This abnormality is detected on both sides in about 50% of cases [2, 3]. In addition to these areas its location in the acromial or scapular region, vulva, in the midline of thorax and abdomen have also been rarely reported [2, 4]. Ectopic breasts enlarge during pregnancy and lactation, they may lactate if they have a normal ductal system. Articles stating that infants were breastfed from ectopic breasts are also present [2]. Adenofibroma, cysts, and carcinomas have also been reported in ectopic breasts containing glandular breast parenchyma, as in normal breast tissue. Carcinomas are reported to be rare [1, 2, 5, 6]. Although carcinoma within the ectopic breast tissue is rare, ductal, lobular, medullary, mucinous, papillary, and invasive secretory (juvenile ) carcinomas have been reported [1, 4, 6]. In its treatment, wide excision , level I-II axillary dissection + radiotherapy (RT) + chemotherapy (CT) + endocrine-hormone therapy (ET) was performed [1, 5-7].

We applied ectopic mastectomy + level I-II axillary dissection to our patient. In ectopic mastectomy, lower and upper flaps were prepared as in standart mastectomy. Because the underlying muscle tissue was very thin, a wide-deep excision extending down to the ribs was performed. The axillary dissection was performed from a separate axillary incision (Figure 2b).

Our surgical procedure is consistent with the literature [1, 5, 6]. However, in the literature, the term “Ectopic Mastectomy” does not exist. We used this terminology because we believe that it completely defines this surgery.

Despite the fact that ectopic mastectomy extended deep down to the ribs, the posterior surface of the mastectomy material contained residual carcinoma. We think that besides the patient’s thin body stature, the absence of a thick muscle layer behind the ectopic breast tissue and the late stage of the disease all contributed to this adverse condition. A CT + RT + ET was planned for the patient after surgery. Four cycles of adjuvant cyclophosphamide 600 mg/m2 and doxorubicin 60 mg/m2 was given followed by paclitaxel 80 mg/m2 after 12 weeks. Radiotherapy at 50 Grays was planned for lymph node positivity. The treatment was completed with 3.6 mg of goserelin and tamoxifen 20 mg/day, and she is still in complete remission. This management plan is also consistent with the literature [1, 5-7].

Conclusion

Data regarding local recurrence and survival in patients with ectopic breast cancer could not be obtained due to its rare incidence. As the number of reported cases increases and records of these patients is held in a diligent manner, it will be possible to access relevant information.

Externally peer-reviewed.

Concept - F.K., S.Ö.; Design - F.K., S.Ö.; Data Collection and/or Processing - S.Ö., A.K.; Analysis and/or Interpretation - M.Ö., S.Ö.; Writer - S.Ö., F.K.

No conflict of interest was declared by the authors.

The authors declared that this study has received no financial support.

References

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