Introduction

Phyllodes tumors (PT) previously known as Cystsarcoma Phyllodes are rare tumors that arise from the connective tissue and periductal stroma of the breast sparing the ducts and the glands. Thus, it is categorized as fibroepithelial tumors of the breast accounting for 0.3% to 1% of all breast tumors [1,2]. The World Health Organization in 2003 has classified Phyllodes tumors into three mains categories based on their histological features, benign, borderline, or malignant [3]. Phyllodes tumors are commonly benign (35% to 64%) with documented malignancy ranging between 10% - 30% [4].

The clinical features of PT carry resemblance to fibroadenomas with variable sizes. However, it has the tendency of rapid growth, multiplicity, active biological behavior, local recurrence, or distal metastasis [5]. The challenge is to achieve accurate diagnosis and be able to perform surgical excision with safety margins. Hereby, we report three cases of Asian women presenting with extreme sizes of PT.

Case presentation

Case 1

40 years old Pilipino a mother of 2 children who lost followup after wide local excision with safe margins of borderline PT in 2018. She presented at this time to the Breast Clinic with a left breast mass of 3 months duration. There was a progressive increase in size associated with pain, skin redness, and a foulsmelling bloody nibble discharge. No other associated symptoms. Menarche at 16 years, strong positive family history of breast cancer was documented. 

Local examination revealed marked asymmetry, enlarged left breast with overlying stretched skin, erythema, and peau d’orange with distortion of nipple and areola complex with ulceration. On palpation confirmed the presence of the mass occupying the center of the left breast, hard in consistency measuring 10x10 cm. with no palpable axillary nodes. (Figure 1a)

Ultrasound demonstrated a large lobulated hypoechoic mass with an angular margin occupying nearly all the breast extending to the nipple, associated with overlying skin thickening and nipple distortion. Multiple axillary lymph nodes with diffused cortical thickening, measuring 13.1x8.7mm, same findings were confirmed by mammogram and was reported BI-RADS 5. (Figure.1b)

Metastatic workup utilizing CT-CAP scan (for chest, abdomen, and pelvis) and the Bone scan was reported as negative. Ultrasound-guided core biopsy of the left breast mass and left axillary lymph node (LN) reported malignant PT of left breast mass and reactive axillary lymphoid tissue.

Mastectomy was the consensus by the Multidisciplinary team (MDT) meeting. The patient underwent left mastectomy and axillary sampling of the enlarged lymph nodes. Breast tissue measured around 26x26 cm and weighed 3.5 kg (Figure 1c)

Immunohistochemical stains showed, Pan-CK highlight limited epithelial elements and marked stromal expansion, Ki-67: 3040 %, ER: positive, CK5/6: weak, P63: highlight myoepithelial cells, Calponin: highlight the myoepithelial cells (Figure 2) The diagnosis was reported as Malignant PT with uninvolved axillary nodes.

 

Figure 1: A. Enlarged breast mass showing stretched erythematous skin with distortion of the nipple areola complex B. Mammogram Craniocaudal view demonstrating a large mass with skin thickening and nipple infiltration C. Demonstrating the mastectomy.

 

Figure 2: A. Section of the lesion shows leaf-like epithelial pattern with sub-epithelial condensation of stromal cells. (H & E, 4x magnification) B. Marked stromal overgrowth displaces the epithelial structures in Malignant Phyllodes Tumor. (H & E, 4x magnification) C. Frequent mitotic figures are noted in the stroma (Arrows). (H & E, 40x magnification) D. Diffuse infiltration of the tumor cells into the surrounding adipose tissue. (H & E, 4x magnification).

Case 2

This is a 59-year- old single Indonesian female noticed 2 years prior to her presentation, it started as a stable painless mass until 4 months prior to presentation as she noticed a rapid increase in size fungating through the skin, associated with skin erythema and yellowish discharge. Negative history of Breast Cancer.

Local examination showed breast had a fungating growth on the left upper breast with palpable left breast mass occupying almost the entire breast (Figure 3a). The remaining examination was unremarkable.

Ultrasound and mammography demonstrated a large illdefined heterogeneous dense mass with multiple internal coarse calcifications and surrounding architectural distortion and parenchymal edema occupying the whole left breast, measuring approximately 15.0 x 12.6 x 14.0 cm. protruding anteriorly with overlying skin thickening, posteriorly abutting the pectoralis muscle, with a few prominent axillary prominent nodes with diffuse cortical thickening is noted (Figure 3b). Reported as BIRADS. Metastatic workup was reported as negative.

Core biopsy of the left breast showed atypical spindle cell lesion with the immunohistochemical stains: P63: Focally positive, CD34: Focally positive, CK 5/6: Negative, CK 8/18: Negative, SMA: Negative, S100: Negative, B- catenin: Negative. With a correlating differential diagnosis of spindle cell carcinoma, phyllodes tumor, and primary or metastatic sarcoma. (Figure 4)

The patient underwent left mastectomy and axillary node sampling based on the MDT meeting consensus. The Final Diagnosis was malignant PT With the presence of 15 Mitosis/ mm² with negative axillary nodes. Due to the size and extent of the disease, adjuvant external beam radiotherapy is suggested.

 

Figure 3: A. Enlarged Breast with supra areolar Fungating mass B. Mammogram demonstrating a large mass occupying the whole breast with skin infiltration and thickening in addition to abutting on the chest wall.

 

Figure 4: A. On low power magnification, stromal overgrowth is noted with presence of malignant heterologous elements (Lipogenic) in Malignant Phyllodes Tumor (H&E, 10x magnification). B. The tumor cells show marked hypercellularity, atypia, frequent mitoses and necrosis [top left corner and bottom right corner] (H&E, 20x magnification).

Case 3

28-year-old Afghani mother of a one-child presented to the breast clinic complaining of a right breast mass of 2 years duration with progressive increase of size and heaviness. It progressed to triple the size of the contralateral breast associated with nipple retraction. No axillary pain or masses. Negative history of breast cancer. Menarche started at age of 17.

 Local examination revealed a large multinodular mass that occupy the whole right breast stretching skin down to the abdomen with erythema and multiple small ulcerations on the lateral side. The right nipple is retracted with no discharge. On palpation, multiple lobulated large masses, firm with stretched overlying warm and tender skins. Contralateral breasts and axillae were unremarkable. (Figure 5)

US and mammogram showed an out-of-range large heterogenous lobulated mass noted occupying the whole right breast estimated measurement is around 22.1 x 18.3 x 22.1 cm with multiple internal cystic apace and central necrosis as well as internal vascularity. Noted, prominent right axillary lymph node measuring 11.3 x 5.0 mm with a cortical thickness of 3.1 mm. The final assessment was BI-RADS 4C, with High suspicion of malignancy.

Core Biopsy was nonconclusive showing a Fibroepithelial lesion with focal coagulative necrosis and no evidence of malignancy. Considering the size of the breast and multiple large disfiguring masses, a mastectomy was performed with excised breast weighing 4.5 kg. (Figure 6). The Final histopathological report showed malignant phyllode tumor that measured 21*20*16 cm. and all the margins were negative for malignancy (Figure 7).

 

Figure 5: Demonstrating the totally replaced breast with large lobulated masses.