Introduction

Autologous fat grafting to the breast is a hot topic in plastic surgery currently, not only in breast reconstruction but also in cosmetic breast augmentation [1, 2]. Remarkable, long-lasting, natural improvements of breast size and shape can be achieved after this surgery [3]. But there are still unidentified concerns about the safety of breast fat grafting, mainly regarding cancer risks [4, 5]. This article describes a case of a 36-year-old woman with mucinous carcinoma in the right breast discovered 2 months after fat grafting.

Case Presentation

A 36-year-old woman received bilateral fat grafting to the breasts (400 ml per breast) (Fig. 1). Prior to the operation, magnetic resonance imaging (MRI) baseline imaging was performed to exclude any abnormality in the breasts. Fat was aspirated from the thighs and was washed and condensed before injection. Two months after the procedure, the patient perceived 2 small palpable indurations in the right breast. On mammography and ultrasound 3 months after the surgery, masses were detected in the subcutaneous layer (Fig. 2). She revisited our facility 9 months after the surgery complaining that the growing lumps were palpable and visible. Physical examination revealed 2 solitary elliptical movable masses in the inferiomedial quadrant of the right breast, measuring 4.5 and 3.5 cm in diameter, respectively. Slight pain was reported against pressure. No significant redness, infection, orange peel, malposition of the nipple, or abnormal discharge were observed. The axillary lymph node could not be palpated. There were no lumps in the left breast or axilla. Systemic examination did not reveal any significant abnormality. On diagnostic imaging, MRI indicated masses with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images (Fig. 2). The subcutaneous masses were removed surgically by intraareolar approach. The excised specimens were grey white with a translucent, mucoid appearance. On gross, the lumps had complete capsules with massive adhesion to the surrounding tissue. Histologic examination of the specimens showed proliferation of neoplastic cells, new vessels and abundant mucus and was diagnosed as mucinous carcinoma (Fig. 3).

Fig. 1
figure 1

Preoperative view of the patient (left) and 9 months after breast augmentation with injection of 400 ml fat in each breast

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Fig. 2
figure 2

The mammography 3 months after the surgery showed a clear lump in the inferiomedial quadrant of the right breast (left). The mass showed low signal intensity on T1-weighted images (middle) and high signal intensity on T2-weighted images (right)

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Fig. 3
figure 3

Above Gross appearance of the lump. The two lumps were elliptical in shape with complete capsules and massive adhesion to the surrounding tissue. The lumps were gray white with a translucent, mucoid appearance. Below Photomicrograph view of the lumps showing proliferation of neoplastic cells, new vessels, and abundant mucus. Hemalaun-eosin staining magnification: ×10 (left) and ×20 (right)

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Discussion

Autologous fat injection into the breast for reconstruction or augmentation purposes has been widely performed recently. Complications include oil cysts, fat necrosis, and calcifications, but the main concern among surgeons is its safety regarding the oncological aspects [6]. In 2008, the French Society of Plastic, Reconstructive and Aesthetic Surgery issued a recommendation to postpone fat grafting to the breast in consideration of oncological risks [7]. To date, no informed consent can be given to patients stating that lipofilling does not stimulate dormant cancer cells or eventually induce new cancer cells [8]. For this patient, a causal link cannot be concluded between autologous fat grafting and cancer; however, it seems essential to discuss several points.

A lot of studies have reported the possible existence of an interaction between cancer and lipofilling to breast from the bench to the clinic. According to the studies of Petti and other researchers, the number of local events in the contralateral breast does not differ between the study group and control group, which indicates that lipofilling does not have a systemic effect [9]. Locally, the role of adipose tissue on tumor cells has been questioned for several reasons. On the one hand, mature adipocytes have been identified to be highly active endocrine cells secreting inflammatory cytokines, growth factors, and extracellular matrix (ECM). Of which, interleukin 6 (IL-6) plays the role of stimulating the invasive behavior of breast cancer cells, and ECM is capable of affecting tumor behavior to be more aggressive and metastasized. On the other hand, in addition to the functions of secreting inflammatory cytokines and growth factors, as the one of the most important preadipocytes in lipoaspirate [8], the role of ADSCs deserves to be questioned. It has been demonstrated in vitro and in animal models that ADSCs could increase migration and metastasis of breast cancer cells by increasing angiogenesis, decreasing local inflammation, and activating receptor site stem cells [10–15]. However, all of the conclusions come from the laboratory, clinical data show no significance in cancer occurrence rates between lipofilling groups and control groups except when the patients all had intraepithelial neoplasia [9, 16]. Considering the occurrence rate of breast cancer, it is of significance to mention that literally one out of 10 females will develop breast cancer during their lifetime, but the incidence is 0.1 % for patients who undergo fat grafting according to existing studies. According to Petit [9], cancer recurrence happened mostly after the third and fourth year after surgery and most of the existing literature does not report such a long mean follow-up period. In addition, the quality of most studies using GRADE is very low or low and the conclusion needs further confirmation by studies with a high level of evidence to further illustrate whether lipofilling could promote tumor cells to proliferate, differentiate, or metastasize or even induce de novo carcinogenesis.

In the case mentioned above, the possibility of inducing de novo carcinogenesis could not be denied. According to the literature, the time that carcinoma in situ develops into invasive carcinoma is 3–5 years. But in the case mentioned above, the tumor was discovered 2 months after the surgery. It is possible that the cancer was just a less than 5-mm diameter carcinoma in situ which cannot be discovered by MRI at the time of surgery. The addition of exoteric stimulus as well as the promoting functions of adipose tissue may have facilitated tumor cell proliferate. Besides, the injection movements could have disseminated the tumor in the breast and participated in the progress of cancer metastasis [17]. All patients undergoing autologous fat grafting should be followed up constantly and special attention should be paid to radiological follow-up [18]. For the previously reported two patients developing breast cancer with no delay, timely screening plays a significant role [9]. In this case, mammography and ultrasound are not so persuasive and sufficient as MRI in distinguishing benign and malignant lesions. Any patient identified with breast cancer, regardless of whether it is a new occurrence and recurrence, it should be recorded and shared worldwide. Further, biopsies may be performed if needed for additional clarification [19, 20].

Conclusions

This unusual case raises the question once again about the relations of lipofilling with breast cancer. As there is no strong scientific evidence in the literature, we suggest a multicenter controlled study on autologous fat grafting to identify or exclude the possibility with careful breast cancer surveillance. In addition, patients who received lipofilling should be carefully monitored over the long term systematically to ensure that the procedures do not mask early detection of cancer.