Kiss Flaps to Repair Large Skin Defect After Excision of Giant Malignant Phyllodes Tumor of the Breast: A Case Report and Literature Review

Yuwei Luo The Second Clinical Medical College of Jinan University Chang Zou The Second Clinical Medical College of Jinan University Jintao Hu The Second Clinical Medical College of Jinan University Pan Zhao The Second Clinical Medical College of Jinan University Yayuan Zhang The Second Clinical Medical College of Jinan University Jianlan Liu The Second Clinical Medical College of Jinan University Wenbin Zhou (  zhouwb1016@163.com ) The Second Clinical Medical College of Jinan University Dongxian Zhou The Second Clinical Medical College of Jinan University


Background
Phyllodes tumors are fairly uncommon broepithelial neoplasms accounting for 0.3-0.9% of all breast tumors [1]. They are fast-growing tumors with benign, borderline, or malignant behavior,depending on histologic features including stromal cellularity, in ltration at the tumor's edge, and mitotic activity. Their size ranges from 1-45 cm and they may occupy the entire breast. Giant phyllodes tumors are typically de ned as those > 10 cm in diameter [2]. Reports in the literature [1,3]have been focused on surgical approaches to tumor resection.An adequate surgical margin is preferred with extended lumpectomy or mastectomy to prevent recurrence and metastasis. However, repair of the skin defect created after wide excision with at least 1 cm of surgical margins is a great challenge to breast surgeons. Repair with a pedicled latissimus dorsi kiss ap has not been reported in the literature. We report a case of giant malignant phyllodes tumor treated with extended lumpectomy followed by successful defect repair with a kiss ap.

Case Presentation
A 26-year-old Chinese woman presented with a giant mass on her right breast, which had enlarged in the past year. The patient visited our breast department on September 18, 2016 because of the rapid tumor growth and the occurrence of skin ulceration with bleeding. Her familial and personal history was noncontributory. Except for the breast tumor, laboratory tests showed no signi cant ndings. Physical examination revealed a protruding and hardened palpable mass occupying almost the entire right breast.
The mass measured approximately 20 × 17 × 13 cm. The skin had been stretched thin, with areas of ulceration and engorged super cial veins. Bilateral axillary lymph nodes were palpable.
A mammogram was not feasible because of the tumor size. Ultrasound of the breast mass indicated a heterogeneous echo and internal structures containing small cystic components, calci cation, and hyperechoic separations, and was classi ed as BI-RADS 4. Multiple enlarged hypoechoic bilateral axillary lymph nodes were detected and some of them had lost their normal internal architecture and fatty hila.
Magnetic resonance imaging (MRI) revealed a giant, lobulated mass with heterogeneous signal intensity, as well as septa and well-circumscribed margins, indicating typical features of phyllodes tumor (Fig. 1).
Image-guided core needle biopsy was performed twice, but a de nite diagnosis was not obtained. The patient underwent extended lumpectomy and axillary lymph node biopsy. Before surgery, a "kiss" ap was carefully designed to cover the skin defect. First, a paper template of the huge skin defect was created. The template was then split into two small pieces of the same size and shape. These paper templates were strategically oriented onto the kiss donor sites, allowing direct primary donor-site closure, and an exact match of the assembled aps to the large defect. The skin defect was 25 × 15 cm. The template was used to mark the aps on the patient's back. The location of the two-lobed ap depended on the vascular pedicle to ensure paddles were nourished by independent myocutaneous perforators from the thoracodorsal artery. An incision was made along the outlined semicircular skin island until the latissimus dorsi muscle was visualized, making sure both aps were connected with the muscle. Before transposing the aps to the chest wall through a subcutaneous tunnel, the two narrow skin paddles were arranged side by side and carefully sutured together to create a "kiss" ap. Finally, the donor site was sutured in layers, and the kiss ap was placed according to the design to cover the chest defect and sutured without tension (Fig. 2). The wound recovered well (Fig. 3).
After surgery, the patient was given six cycles of chemotherapy with docetaxel (160 mg), epirubicin (100 mg), and cyclophosphamide (800 mg). The patient also received twenty-ve fractions of adjuvant chest irradiation treatment (Total 50 GY). The patient was followed up for more than 4 years postoperatively, and there was no local recurrence or distant metastasis.Currently the timing of further reconstructive surgery is appropriate for her to plan a delayed implant reconstruction of the right breast.

Discussion
Phyllodes tumor is a disease of the epithelial and stroma tissue in the breast. It is classi ed as benign, borderline, and malignant. Malignant tumors have high stroma cellularity and tend to be permeative whereas benign tumors have low stroma cellularity and are circumscribed [4]. Malignant phyllodes tumors is distinguished only pathologically by identi cation of marked stromal cellularity, more than 5 mitoses per 10 high-powered elds, invasive margins, and marked stromal overgrowth [5]. Giant phyllodes tumors are rare broepithelial breast neoplasms typically > 10 cm in diameter by de nition [2]. In general, it is di cult to differentiate phyllodes tumors from benign broadenoma by clinical presentation, radiology, or even core needle biopsy [6]. The most accurate diagnosis of breast phyllodes tumor is postoperative pathology [7]. Unlike breast cancer which can be downsized by neoadjuvant therapy, phyllodes tumor is not sensitive to chemotherapy or radiotherapy or endocrine therapy [8][9]. Surgery is regarded as the primary treatment method of phyllodes tumors. Negative margins rather than surgery type, such as extended lumpectomy or total mastectomy, determine the recurrence rate [10]. The National Comprehensive Cancer Network guidelines [11] advocate a wide excision with surgical margins of 1 cm or more. A negative margin is an independent prognostic factor for disease-free survival and local recurrence [5,[12][13]. Patients with a positive margin and malignant histology should undergo further surgery to obtain clear margins [3].
Although extended lumpectomy or mastectomy with adequate surgical margins is the best choice for large malignant phyllodes tumors, the resulting large skin defect always requires a skin graft or transplanted ap. To the best of our knowledge, this case is the rst documented use of a kiss ap to repair the large skin defect resulting from removal of a giant malignant phyllodes tumor of the breast. There are some other options to repair the defect such as a transverse rectus abdominis myocutaneous (TRAM) ap or a deep inferior epigastric artery perforator (DIEP) ap.TRAM and DIEP can immediately reconstruct a new breast after mastectomy. Although DIEP and TRAM have little in uence on pregnancy, the young girl has not been married or pregnant, she worried about a long scar on the abdominal wall would affect beauty and future pregnancy. Moreover, DIEP and TRAM need a long operative time and are highly traumatic, and DIEP requires microsurgical techniques. The young girl also worried about a quick recurrence soon after surgery, so she refused complicated immediately breast reconstruction such as DIEP and TRAM and wanted to choose a simple procedure. The latissimus dorsi ap is close to the postoperative chest wound and usually be used to repair the chest wall defect after breast dissection. However, the skin of the back lacks elasticity, the donor area cannot be directly sutured and generally requires a skin graft if the width of the ap exceeds 8 cm. This prolongs postoperative recovery and limits the wide application of the latissimus dorsi ap. The kiss ap involves the excision of double skin paddles, which has an independent blood supply from the donor stem. These paddles are spliced in the recipient area, so that they "kiss" each other side-by-side, to create a much larger ap, accurately matching the size of the defect. This technique allows exible design of the ap shape, while increasing the surface area of skin ap coverage and minimizing incision dehiscence and non-healing complications [14]. A careful presurgical ap design is necessary to make maximum use of the limited human tissue available and ensure minimum damage while performing the autologous tissue transfer.
The functional and aesthetic outcome of the donor site should also be considered. In this case, the postoperative ap had a good appearance with no hyperplastic scar and the activities of shoulder joint were not affected. The outcome of this case suggests that the kiss ap is a simple and feasible technique for repair of large skin defect following giant phyllodes tumor resection.If there is no recurrence or metastasis more than one year after surgery, the patient may plan a delayed breast reconstruction. After communication with the patient, she planned a delayed implant breast reconstruction plus fat grafting.
Local recurrence of phyllodes tumors has been associated with positive margins, younger age, larger tumor size, and malignant pathologic diagnosis [1,[15][16]. The tumors rarely spread via the lymphatic system and axillary lymph node metastasis rate is < 5%. Therefore, axillary lymph node dissection is unnecessary, yet the removal of suspicious axillary lymph nodes is recommended [17,18]. In this case, axillary lymph node biopsy was carried out because some lymph nodes were found adjacent to the tumor during surgery. However, postoperative pathology proved that all the lymph nodes were negative. Studies have shown that adjuvant radiotherapy can lower the rate of local reoccurrence, particularly for patients with positive margins for borderline and malignant tumors [19][20][21]. Margin-negative resection combined with adjuvant radiotherapy is very effective for local control and prevention of recurrence [6]. Adjuvant chemotherapy is not the standard care since it is of controversial value for malignant phyllodes tumors, yet some institutions support doxorubicin-based adjuvant chemotherapy for rst-line treatment of breast sarcomas, especially with > 5.0 cm large high-risk tumors [22][23]. During postoperative follow-up, no local recurrence or distant metastasis were found.

Conclusion
The kiss ap could be considered as an effective method to repair large chest wall defects after resection of giant phyllodes tumors.

Declarations Ethics Statement
We obtained written informed consent from the patient presented in this case report in accordance with the Helsinki Declaration of 1975. The patient consented to the treatment and the use of her data, including photos, for research, and publication. This study was approved by the medical ethics committee of Shenzhen People's Hospital.

Consent
Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Availability of Data and Materials
This was not applicable to this manuscript. Figure 1 Imaging data of the patient. (A) Ultrasound of the right breast mass shows small cystic components, calci cation, and hyperechoic separations. (B) Magnetic resonance imaging of the breast reveals a giant, lobulated mass with heterogeneous signal intensity, as well as septa and well-circumscribed margins, typical of a phyllodes tumor.