
==== Front
Int J Surg Case Rep
Int J Surg Case Rep
International Journal of Surgery Case Reports
2210-2612
Elsevier

S2210-2612(24)00943-X
10.1016/j.ijscr.2024.110162
110162
Case Report
Coexistence of benign phyllodes tumor and invasive ductal cancer in the ipsilateral breast: A case report
Shinzaki Wataru shinzaki@med.kindai.ac.jp
a⁎
Terashita Daisuke a
Kanaizumi Hirofumi a
Wakasa Tomoko b
Kimura Yutaka c
Komoike Yoshifumi d
a Department of Breast and Endocrine Surgery, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara 630-0293, Japan
b Department of Diagnostic Pathology, Kindai University Nara Hospital, 1248-1 Otoda-cho, Ikoma, Nara 630-0293, Japan
c Department of Surgery, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara 630-0293, Japan
d Division of Breast and Endocrine Surgery, Department of Surgery, Faculty of Medicine, Kindai University, 377-2, Ohnohigashi, Osakasayama, Osaka 589-8511, Japan
⁎ Corresponding author. shinzaki@med.kindai.ac.jp
13 8 2024
9 2024
13 8 2024
122 11016212 7 2024
6 8 2024
10 8 2024
© 2024 The Author(s)
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction and importance

Phyllodes tumors (PTs) are rare breast neoplasms, with an incidence rate of <1 %. Further, the coexistence of PTs and carcinoma is also uncommon. In this report, we describe a rare case of the synchronous coexistence of a benign PT and invasive ductal carcinoma (IDC) of the ipsilateral breast.

Case presentation

A 42-year-old woman presented with a 6-month history of a tumor in her right breast. Mammography and ultrasonography revealed a 9.0 cm breast lump, and core biopsy revealed a benign PT. A simple mastectomy of the right breast revealed IDC foci in the mammary area, close to the benign PT. Right axillary lymph node staging was performed by surgery. However, no lymph node metastasis was observed. Subsequently, appropriate adjuvant therapy was initiated. Currently, the patient is doing well.

Clinical discussion

Breast cancer may be located close to the PT of the ipsilateral breast and is difficult to detect preoperatively, especially in cases of large PTs. Early detection of the presence of a coexisting carcinoma is clinically important because it can alter patient management.

Conclusion

Careful assessment of the PT using additional breast imaging tools might help identify their coexistence with breast cancer in cases of difficult diagnosis of coexistent tumors using standard breast imaging tools such as mammography or ultrasound.

Highlights

• We describe a rare case of coexistence of a benign PT and IDC.

• Early detection of the presence of a coexisting carcinoma is clinically important.

• Imaging tools other than standard breast imaging tools should be used in such cases.

Keywords

Phyllodes tumor
Invasive ductal carcinoma
Synchronous cancer
Breast cancer
Case report
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pmc1 Introduction

Phyllodes tumor (PT) is an uncommon fibroepithelial tumor involving a biphasic proliferation of the stroma and breast epithelium, accounting for under 1 % of all breast neoplasms [1]. PT is a fast-growing breast tumor; most PT are histologically benign [2]. Since surgical excision provides the most definitive diagnosis, if there are findings that may raise clinical suspicion for PT, such as rapid growth, excisional biopsy should be performed regardless of the results of core needle biopsy.

The coexistence of PT and carcinoma is uncommon. Here, we report a rare case of the synchronous coexistence of benign PT and invasive ductal carcinoma (IDC) of the ipsilateral breast. This case report has been reported in line with the SCARE 2023 criteria [3].

2 Case report

A 42-year-old woman presented with a 6-month history of a tumor in the right breast. She reported a family history of breast cancer, asthma, and atopic dermatitis. Clinical examination revealed a large mass in the lateral area of the right breast. The mass was non-tender, well-defined, and mobile. Nipple retraction was not observed. The patient's left breast was normal. No palpable lymph nodes were found in the axillary or supraclavicular regions. Mammography revealed a high-density mass with a diameter of 9.0 cm and regular margins (Fig. 1). Ultrasonography of the mammary gland revealed a hypoechoic, heterogeneous, lobulated, solid mass with a regular border and no calcification (Fig. 2). The mass was diagnosed as a benign PT by core-needle biopsy. We were unable to perform a contrast-enhanced magnetic resonance imaging (MRI) because the patient had asthma.Fig. 1 Mammography showing a high-density mass with a regular margin in the upper outer quadrant of the right breast.

Fig. 1

Fig. 2 Ultrasound scan of the right breast revealing a heterogeneous vascular mass with fairly well-circumscribed margins in the right breast.

Fig. 2

A wide partial resection with reconstruction was recommended for the large benign PT; however, the patient preferred mastectomy, and did not wish to undergo simultaneous reconstruction. We performed a simple mastectomy of the right breast. Grossly, the mass measured 86 × 71 mm and appeared well-circumscribed (Fig. 3). Histopathological examination revealed a well-circumscribed mass with biphasic morphology comprising an epithelial component and cellular spindle stroma. Fibroepithelial lesions exhibited a leaflike architectural pattern. The cellular stroma was formed of spindle cells without atypia and with a low mitotic count (<5/10 high-power fields [HPF]). Areas of necrotic change were not noted, which was consistent with the diagnosis of benign PT (Fig. 4A). In the mammary gland, seen in the inner area close to the mass, there was an IDC with the greatest dimensions of 32 mm (Fig. 3, Fig. 4B). All margins were negative. Immunohistochemical staining of the IDC cells showed strong positivity for estrogen and progesterone receptors and negativity for human epidermal growth factor receptor 2 (HER2) with a score of 0, and 27.2 % of the cells showed positive Ki-67 staining. Lymphovascular invasion (LVI) was not observed. Following the pathological review, the patient underwent a complete staging workup, including a bone scan and liver ultrasound. The patient showed negative results for distant metastasis. Subsequently, axillary staging was performed based on axillary lymph node biopsy. The frozen sections of five axillary lymph nodes were intraoperatively evaluated; the results were negative for metastatic disease. Moreover, since several other swollen lymph nodes suspected of metastasis were found intraoperatively, dissection of nineteen axillary lymph nodes was performed. No lymph node metastasis was observed. Biological profiling classified the tumor as luminal B type. In adjuvant systemic therapy, because the 21-gene assay for breast cancer showed a low recurrence risk score, the patient received endocrine therapy, and chemotherapy was omitted. No recurrence of PT or carcinoma was observed 18 months after the secondary surgery.Fig. 3 Macroscopic findings of the resected right breast. One mass is large and well-circumscribed (thick arrow). A small mass is seen in the inner area close to the mass (thin arrow).

Fig. 3

Fig. 4A Microscopic photo showing classical leaflike areas in a benign phyllodes tumor. (H&E × 40).

Fig. 4A

Fig. 4B Microscopic photo showing invasive ductal carcinoma. (H&E × 400).

Fig. 4B

3 Discussion

PT are fibroepithelial breast tumors and account for under 1 % of all breast neoplasms [1]. Breast cancer can coexist with PT with synchronous and is even uncommon, occurring in only 1–2 % of patients with PT [4,5]. İlhan et al. reported that most of carcinoma associated with PT were ductal carcinomas in situ (DCIS) [6].

Breast cancer may coexist with PT in two situations: within the PT of the ipsilateral breast or separate from the PT of the ipsilateral breast. Although the etiology might be coincidental in carcinomas arising away from the PT [7], the underlying etiology of carcinomas occurring within the PT remains unknown. In this case, the PT and IDC were close to each other but not continuous and were thought to have occurred independently in the ipsilateral breast.

If breast cancer coexists within or close to the PT, preoperative assessment of the existence of coexisting carcinoma is difficult because the PT usually takes up a large area. Gemci et al. reported that all cases out of 4 patients with carcinoma within the PT were diagnosed on final histology [8]. Co et al. reported that ultrasound and mammogram examination of the 5 patients with coexisting DCIS in the PT did not reveal any suspicious radiologic features [9]. Similarly, in the present case, the PT was large, and the two tumors were so close together that the cancer could not be identified preoperatively. Standard breast imaging tools such as mammography and ultrasound alone may not be able to differentiate the malignant breast tumor from the PT, especially in cases of large PTs. However, if we were aware of its coexistence with cancer and carefully observed the area near the PT, we would have been able to detect the cancer.

Radiologically, MRI is a useful tool for diagnosing breast PT. PT showed internal non-enhanced septations, silt-like patterns on enhanced images, and signal changes from T2-weighted to enhanced images correlated with the histologic grade [10,11]. MRI showed findings typical of ductal carcinoma, an irregular mass with segmental and regional enhancement, demonstrating a rapid increase in signal intensity following contrast enhancement followed by rapid washout. Franceschini et al. reported that MRI enabled complete visualization of the tumor, as well as clear delineation from healthy glandular tissue, and may help define the appropriate surgical management of PT [12]. However, MRI is limited because of the need for caution in patients with renal impairment and asthma.

Contrast-enhanced ultrasound (CEUS) has high accuracy in differentiating benign from malignant lesions by analyzing the enhancement characteristics and calculating the time-intensity curve's quantitative parameters [13]. Miyamoto et al. reported that CEUS using sonazoid was confirmed to be superior to unenhanced ultrasound and MRI for the differential diagnosis of benign from malignant focal breast lesions in terms of diagnostic accuracy, suggesting that CEUS was able to identify the extent of invasion clearly [14]. In addition, CEUS using sonazoid is considered a replacement for MRI for the differential diagnosis of breast masses because sonazoid could also be used for the diagnosis of breast lesions without safety concerns. Although we were unable to perform an MRI because the patient had asthma, the addition of preoperative CEUS could have detected coexisting breast cancer close to the PT.

Treatment of PT generally involves wide local excision. Margins should be 1–2 cm, unlike the treatment for fibroadenoma, for which enucleation is recommended. Obtaining adequate margins during excision of the PT appears to help prevent recurrence, which is common in PT, and prevent the need for re-excision if the tumor is malignant. Lui et al. reported that only 8 of 41 cases of PT underwent wide local excision, while the rest underwent total mastectomy [2]. As PT typically behaves more like a sarcoma and does not usually metastasize to the axillary lymph nodes, the standard treatment for PT does not involve axillary sampling or dissection. The presence of coexisting carcinoma on postoperative pathology considerably alters management. Early-stage invasive breast cancer is typically treated with lumpectomy, adjuvant radiation therapy, or mastectomy. The determination of an appropriate systemic therapy predominantly depends on the characteristics of the individual breast tumor, such as immunohistochemical status and axillary lymph node metastasis status. In the present case, due to the presence of an IDC close to the PT, right axillary lymph node staging after the initial mastectomy was performed by surgery to evaluate axillary lymph node metastasis. The results were negative for metastatic disease. The patient is currently receiving adjuvant endocrine therapy, and was disease-free at follow-up, with no recurrence of PT or carcinoma.

Breast cancer may be located within or close to the PT of the ipsilateral breast and is difficult to detect preoperatively. Recognizing the coexistence of PT and breast cancer may enable early detection and improve patient management.

4 Conclusion

Here, we present a rare case of synchronous coexistence of benign PT and IDC in the ipsilateral breast. Detecting the presence of coexisting carcinoma preoperatively on mammography or ultrasound is often difficult owing to the large size of the associated PT. Careful assessment of the PT using additional breast imaging tools such as MRI or CEUS might help identify the coexistence of breast cancer in cases of high indices of suspicion or difficult diagnosis of coexistent tumors using standard breast imaging tools.

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 on request.

Ethical approval

Single-case reports are exempted from ethical approval in our institution, Kindai University Nara Hospital.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Author contribution

Wataru Shinzaki: Conceptualization of the case report, data curation, writing original draft. Hirofumi Kanaizumi: Editing, writing review. Daisuke Terashita: Editing, writing review. Tomoko Wakasa: Curation and analyzation of the patient's pathological findings. Yutaka Kimura: Editing, writing review. Yoshifumi Komoike: Supervision, editing.

Guarantor

Wataru Shinzaki.

Research registration number

Not applicable

Conflict of interest statement

The Authors declare that there is no conflict of interest.
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