Phyllodes Tumor of the Breast: Pathology, Histogenesis, Diagnosis, and Treatment

The phyllodes menace-Variation in course, therapy, and appearance of phyllodes tumors in a case series of three patients

Key Clinical Message

Early and complete surgical resection is the most important therapeutic and diagnostic measure. Adjuvant radiation is suggested for malign phyllode tumors, phyllode tumors larger than 10 cm or those with a low distance to the resection margins.

Abstract

Phyllodes tumors are rare fibroepithelial tumors of the breast. Histologically, they are usually classified as benign, borderline or malignant, though these classifications do not necessarily reflect the clinical course of the disease. These tumors may stay undetected for years, or show sudden and rapid progression. There is currently no consistent therapy recommendation based upon histological findings, the localization of the tumor and/or whether it is recurrent. Using the examples of three patients, we show how courses and therapy may differ widely, and discuss this in the context of the current state of the literature.

Droplet-digital PCR reveals frequent mutations in TERT promoter region in breast fibroadenomas and phyllodes tumours, irrespective of the presence of MED12 mutations

BACKGROUND

Breast fibroadenoma (FA) and phyllodes tumour (PT) often have variations of gene mediator complex subunit 12 (MED12) and mutations in the telomerase reverse transcriptase promoter region (TERTp). TERTp mutation is usually tested by Sanger sequencing. In this study, we compared Sanger sequencing and droplet-digital PCR (ddPCR) to measure TERTp mutations in FA and PT samples.

METHODS

FA and PT samples were collected from 82 patients who underwent surgery at our institution from 2005 to 2016. MED12 mutations for all cases and TERTp mutations for 17 tumours were detected by Sanger sequencing. ddPCR was performed to analyse TERTp mutation in all cases.

RESULTS

A total of 75 samples were eligible for analysis. Sanger sequencing detected MED12 mutations in 19/44 FA (42%) and 21/31 PT (68%). Among 17 Sanger sequencing-tested samples, 2/17 (12%) were TERTp mutation-positive. In ddPCR analyses, a significantly greater percentage of PT (19/31, 61%) was TERTp mutation-positive than was FA (13/44, 30%; P = 0.0046). The mutation positivity of TERTp and MED12 did not correlate, in either FA or PT.

CONCLUSIONS

ddPCR was more sensitive for detecting TERTp mutation than Sanger sequencing, being able to elucidate tumorigenesis in FA and PT.

A giant phyllodes tumor causing ulceration and severe breast disfigurement: case report and review of giant phyllodes

Phyllodes tumors are rare fibroepithelial tumors that account for <1% of the breast tumors in women. These tumors are often benign unilateral lesions of the female breast (70%). Less common are malignant phyllodes, which have the potential for hematogenous spread. Phyllodes tumors can be seen in all age groups, and the median age of presentation is 45 years. Surgery is the main form of treatment. Wide excisions with margins of 1cm are suggested. While smaller and moderate size phyllodes may typically be seen, gigantic ones are very rare. These may be seen in neglected tumors. By definition, a giant phyllodes tumor is one larger than 10 cm in diameter. We report a gigantic phyllodes tumor that grew over 7 years period causing significant ulceration and disfigurement and review features of these tumors and management.

Five-Year Disease-Free Follow-Up of a Borderline Breast Phyllodes Tumor in a 15-year-old Patient

Phyllodes tumors are large breast tumors representing only 1% of breast neoplasms and are rarely seen in young women. Histologically, phyllodes tumors are classified as benign, borderline, or malignant based on the characteristics of the stroma. Although wide local excision is recommended for the treatment modality, the reoccurrence rate after surgical excision varies between 36% and 65%, with recurrence more likely in those with the tumor at the margins of excision. Our aim was to report -a case in a 15-year-old girl with a 115-mm borderline phyllodes tumor in her left breast mimicking a juvenile fibroadenoma. We presented a 5-year disease-free follow-up after wide local excision with negative margins.

A case of large phyllodes tumor causing "rupture" of the breast: a unique presentation

Introduction. Phyllodes tumors are rare fibroepithelial tumors which constitute less than 1% of all known breast neoplasms. The importance of recognizing these tumors lies in the need to differentiate them from fibroadenomas and other benign breast lesions to avoid inappropriate surgical management. We report a case of large phyllodes tumor which caused rupture of the breast and presented as an external fungating breast mass, a presentation which is exceedingly rare. Case Presentation. A 32-year-old female presented with a 1-year history of a mass in her right breast and eruption of the mass through the skin for the last 3 months. On physical examination, an ulcerated, irregular, and nodular mass measuring 9 × 8 cms was found hanging in the lower and outer quadrant of the right breast. Ultrasonography revealed an exophytic mass with heterogeneous echotexture and vascularity. Under general anesthesia, the tumor was excised. The resected specimen was 9.5 × 8.5 × 4.5 cm in size and the tumor was not invasive to the surrounding tissues. Histological examination confirmed a benign case of Phyllodes tumor. Conclusion. Clinicians should be aware of the myriad ways in which Phyllodes can present. A rapidly growing breast mass in a female should raise strong suspicion for Phyllodes. It is necessary to differentiate it from fibroadenomas to avoid inappropriate surgical management which may lead to local recurrence.

A case of phyllodes tumor of the breast with a lesion mimicking fibroadenoma

We report a case of phyllodes tumor (PT) with multiple lesions partly mimicking fibroadenoma (FA). A 43-year-old woman was referred to our institute because of a left breast mass which was diagnosed as FA clinically. During the follow-up, the mass gradually enlarged and excisional biopsy was performed to rule out malignant lesion. On histological examination, the tumor consisted of three different components; a lesion diagnosed as FA, another lesion as benign PT, and the other lesion as borderline PT. Finally, the tumor was diagnosed as borderline PT. Stromal cellularity may vary from area to area in any given PT. If there are some disagreements among the findings of imagings and cytology for the diagnosis of FA, as was seen in our case, the possibility of coexistence of PT should be considered.

Perioperative diagnosis of cystosarcoma phyllodes of the breast may be enhanced by MIB-1 index

BACKGROUND

The recurring theme in cystosarcoma phyllodes (CSP) is one of underdiagnosis by pathologists and undertreatment by surgeons. Major areas of investigation relating to the diagnosis of CSP center on accurate preoperative diagnosis, elucidating the relevance of histological classification with respect to outcome, and identifying novel markers to reliably differentiate CSP from fibroadenoma (FA).

MATERIALS AND METHODS

Fifteen CSP and 7 cellular FA controls (where the preoperative diagnosis was unclear) were retrospectively investigated. Preoperative histological and radiological investigations were reviewed for efficacy. The ability of MIB-1 antibody to differentiate the two fibroepithelial lesions was investigated using immunohistochemical estimation of the MIB-1 index.

RESULTS AND DISCUSSION

Preoperative core biopsy had a sensitivity of 75% but was carried out in only 23% of cases. Fine needle aspiration cytology and radiological assessment were not efficacious in preoperative diagnosis. Proliferative activity (MIB-1 indices) was significantly higher in CSP than in a selected population of FA where there was preoperative diagnostic uncertainty (P < 0.0001). Indices were also able to determine CSP subclassification. This suggests MIB-1 as a constructive adjunctive investigation when evaluating histological features to differentiate CSP from FA in difficult cases.

CONCLUSIONS

The use of MIB-1 may increase the sensitivity of preoperative core biopsy diagnosis, offering more effective surgical planning and decreasing immediate reoperation rates.

Immunohistochemical study of MIB1 expression in phyllodes tumor and fibroadenoma

The histogenesis of phyllodes tumor (PT) and fibroadenoma (FA) is closely related, and discrimination between them by histopathological analysis is sometimes problematic. Moreover, objective criteria by which to categorize the grade of malignancy in PT are still controversial. The aim in this study is to clarify whether immunohistochemical evaluation using the MIB1 antibody, which reacts with the ki-67 antigen, correlates with the histological grade of malignancy in PT, and can discriminate between PT and FA. The 47 cases of phyllodes tumor (PT) were categorized into three groups (malignant, 4 cases; borderline, 6 cases; benign, 37 cases) according to the criteria proposed by Azzopardi (1979) and were investigated by immunohistochemistry. There were significant differences in stromal MIB1-index among the three groups (P < 0. 0001), and, unexpectedly, benign PT was easily divided into two groups according only to the MIB1-index. There were significant differences in the stromal MIB1-index (P < 0.001) and stromal cellularity (P < 0.01) between the two benign PT groups. A total of 478 cases of FA was reviewed and these were divided into 403 conventional fibroadenomas (CFA), 36 cellular fibroadenomas (CEFA) and 39 fibroadenomas with focal phyllodes structure (FAPS). All cases of CEFA and FAPS, and 140 cases of CFA were studied by immunohistochemistry. The 21/215 (9.8%) cases of FA, which were designated as FAMIB, showed a high stromal MlB1-index (more than 10/0.0625 mm2). Conversely, 77% cases of FA showed no MIB1-positive stromal cells. The incidence of MIB1-positive epithelium of FAMIB was much higher than that of FA. These results suggest that high proliferative activity may be present in both stromal and epithelial cells of FAMIB. Our study suggests that immunohistochemical evaluation using MIB1 antibody correlates with the histological grade of malignancy in PT, and can select FA with high proliferative activity. However, new objective diagnostic factors useful for discriminating FA from benign PT with a low MIB1-index should be developed.

A Case of Phyllodes Tumor with Bloody Nipple Discharge in Juvenile Patient

We report a rare case of phyllodes tumor of the breast in a juvenile patient with bloody nipple discharge. An 11-year-old girl had a chief complaint of a palpable 5 cm well-circumscribed tumor with nipple discharge in the left breast. The histopathological diagnosis of the resected specimen was benign phyllodes tumor showing extensive areas of hemorrhagic necrosis. The bloody nipple discharge was caused by spontaneous infarction of the tumor. Preoperative ultrasonography and galactography were helpful in evaluating the mechanism of nipple dicharge from the tumor. Although phyllodes tumor must be differentiated from fibroadenoma, the present case was histopathologically identical to phyllodes tumor.

Phyllodes tumor showing intracystic growth: a case report

A phyllodes tumor often grows rapidly and occasionally contains microcysts; however, the tumor rarely shows a morphologically intracystic pattern. We experienced a rare case of a phyllodes tumor with a solid mass growing into the cyst. A 62-year-old female noticed a tumor in her right breast in January 1995. The tumor grew rapidly and she visited our out-patient clinic in February 1995. On physical examination, a 10 x 8 cm, well defined and movable mass with a smooth surface was palpated in the upper outer quadrant of the right breast. Mammography showed a large tumor shadow in the upper outer quadrant of the right breast without any microcalcification. Ultrasonography revealed a large cystic shadow with a low echoic lesion and solid component with heterogeneous internal echo in the cyst. Under general anesthesia, the tumor was widely excised. The resected specimen was 11.5 x 11 x 11 cm in size and the tumor was not invasive to surrounding tissues. Old bloody fluid was contained within the cyst. The gross appearance showed papillary process protrusions into a central cystic cavity. Histological examination revealed a borderline case of phyllodes tumor. Two years after the operation, she is doing well without any recurrence.