Abstract
BACKGROUND:
Pseudoangiomatous stromal hyperplasia is a rare benign breast stromal proliferative lesion of the breast. Clinical presentation ranges from rapidly growing mass to incidental identification in routine screening. This difference in manifestation and its rarity makes it difficult to be a standard treatment protocol. Therefore, we aimed to share our clinical experience in Pseudoangiomatous stromal hyperplasia.
METHODS:
The files of patients who underwent core biopsy or surgical excision due to a breast mass and resulted in pseudoangiomatous stromal hyperplasia between January 2013 and December 2021 were included in the study.
RESULTS:
17 patients with a median age of 37 (22–68) were found Pseudoangiomatous stromal hyperplasia confirmed by surgical excision or core biopsy. Chosen treatment option was observation in 8 patients (47.1%), while surgical excision was used in 9 (52.9%) patients. The mean follow-up period was 55.24 ± 26.72 (13–102) months. None of the patients observed the Malignant transformation during the follow-up period.
CONCLUSION:
For Pseudoangiomatous Stromal Hyperplasia of the breast, surgical excision with clean margins or close follow-up after diagnosis confirmation by tissue biopsy is sufficient. Pseudoangiomatous Stromal Hyperplasia is not a risk factor for developing breast cancer.
Introduction
Pseudoangiomatous stromal hyperplasia (PASH) is a benign proliferative lesion of the breast stromal cells. It was first defined by Vuitch et al. in 1986 [1]. PASH generally presents with a slow-growing mass that is typically solitary, firm, painless, and mobile. PASH was characterized by myofibroblast-lined, slit-like spaces resembling blood vessels surrounded by dense, collagenous stroma that may require differentiation from low-grade angiosarcoma [2]. Presentation varies from a palpable mass on physical examination, and a new finding in imaging studies to incidental findings on biopsies perform another reason. PASH is shown benign in most of the literature, although few studies suggest presenting in biopsies of invasive carcinoma [3,4].
Ultrasonography (USG) and mammography (MMG) imaging with clinic presentation mostly lead to misdiagnoses of fibroadenoma [5,6]. On MMG, PASH presents as a focal asymmetry that should prompt further diagnostic imaging to define the lesion better [4]. USG shows PASH as a well-circumscribed, hypoechoic, or isoechoic oval mass. These standard radiographic features make it difficult to distinguish from other benign and malignant lesions and lead to core needle biopsy. After diagnosis by tissue biopsy, these lesions may be safely followed with routine screening follow-up in the absence of interval growth or other suspicious radiologic findings [7].
In this study, we aimed to share our experiences with patients with PASH diagnosed with core biopsy and followed up or primarily underwent surgical excision.
Methods
The files of patients who underwent core biopsy or surgical excision due to a breast mass in our clinic between January 2013 and December 2021 were reviewed retrospectively. Patients with pseudoangimatous stromal hyperplasia resulting from pathology were included in the study. Patients with missing data or follow-up were excluded from the study. Patients’ demographic characteristics, presentation, radiological imaging features, menopausal status, treatment methods, pathological reports, and clinical follow-ups are recorded from the medical records for evaluation.
The treatment option was determined by the physician’s preference based on core biopsy results, radiological findings, and clinical presentation. Surgical excision or follow-up after core biopsy is applied in our clinical due to our experience. Core biopsy was performed with a 14-gauge automated core needle under USG guidance. Recurrence was defined by the presence of a mass on imaging in the follow-ups of patients who underwent total surgical excision. Progression was defined as an increase in the volume of a mass that had confirmed PASH with core biopsy on following image studies after diagnosis.
Results
A total of 17 patients were found with PASH to be confirmed by surgical excision or core biopsy. All patients were women with a median age of 37 (22–68). Twelve patients are in the pre-menopausal period, and five are in the post-menopausal period. While the mass was unilateral in all patients, it was in the right breast in 10 (58.8%) patients and the left breast in 7 (41.2%) patients. Mass located upper outer quadrant in 11 (64.7%) patients, subareolar in two (11.8%) patients, upper inner quadrant in two (11.8%) patients, lower outer quadrant in one (5.9%) patient, and lower inner quadrant in one (5.9%) patient. The presentation was a palpable mass lesion in 12 (70.6%) patients and mastodynia in 3 (17.6%) patients. In two (11.8%) patients, breast masses were detected in routine breast exams. Clinical presentation and patients characteristics are presented in Table 1.
Characteristics of patients with pseudoangiomatous stromal hyperplasia
Characteristics of patients with pseudoangiomatous stromal hyperplasia
∗Progression During Follow-up. ∗∗Recurrence after surgical excision. UOQ; Upper outer quadrant. UIQ; Upper Inner quadrant. LOQ; Lower Outer quadrant. LIQ; Lower Inner quadrant. SA; Subareolar. MMG; Mammography. USG; Ultrasonography.
USG was performed in all patients, while MMG was performed in 12 (70.6%) of 17 patients. MMG was not applied to all patients in our study because of the low imaging quality of dense breast tissue in young patients. Furthermore, magnetic resonance imaging (MRI) was performed on five patients. The median size of the mass was measured at 3.5 (1.1–9.0) cm in length by USG. USG described 14 (82.4%) of the masses as round, while the other 3 (17.6%) were described as oval. Sonographic mass echo patterns were 8 (47.1%) hypoechoic, 8 (47.1%) isoechoic, and 1 (5.8%) heterogeneous. MMG findings were circumscribed mass in 4 (33.3%) patients, typical in 4 (33.3%) patients, lobulated mass in 3 (25.0%) patients, and focal asymmetry density in one (8.3%) patient. MRI was performed in 4 surgical excision cases to not miss any other pathology due to the large size of the breast tissue.
Treatment options differ in patients due to clinical presentation. Chosen treatment option was observation in 8 patients (47.1%), while surgical excision was used in 9 (52.9%) patients. The mean follow-up period was 55.24 ± 26.72 (13–102) months. One patient (12.5%) developed progression in the observation group at the 12th month of follow-up, and surgical excision was performed. Up to date, 36th month of the surgical excision of this patient and no recurrence was found during physical examination or radiological imaging. In the surgical excision group, one patient (11.1%) developed recurrence in the 50th month of the follow-up, and re-excision was performed. The pathology result of the re-excised mass was compatible with PASH.
PASH is a rare benign fibroblastic stromal lesion of the breast characterized by anastomosis of slit-like spaces in a hyalinized stroma [1]. Patients with PASH are typically present in pre-menopausal or peri-menopausal women [7]. In our study, all patients were women with a median age of 37 (22–68), which is consistent with the literature. Clinical presentation ranges from rapidly growing mass to incidental identification in routine screening. Yoon et al. revealed that PASH was detected clinically during the routine breast screening of 50%, subjective symptoms in 36.4%, and 13.6% during the screening of another mass [8]. In our study, most of the patients (70.6%) presented with the complaint of a palpable mass in the breast. This difference in clinical presentation is that the median size of the masses was 2.3 cm in Yoon et al.’s study and 3.5 cm in our study.
In MMG, PASH can typically be seen as a well-circumscribed, round to oval mass, or it may not be seen [9,10]. In our study, the most common MMG findings of PASH patients were mostly circumscribing mass (33.3%), normal (33.3%), or lobulated mass (25%). USG shows PASH mostly as a well-circumscribed, hypoechoic, isoechoic, round, or oval-shaped mass [9,10]. Rarely, it may have poorly defined, irregular borders or heterogeneous echogenicity, resulting in BIRADS 4 classification, thus resulting in biopsy requirement. Since there was no limitation to the use of USG in breast imaging, it could be applied to all patients in our study. Our study’s most common USG findings were the isoechoic round (41.2%) and the hypoechoic round (41.2%).
Due to its rarity and being a new entity, there are no clinical guidelines for the management of PASH. Several studies support clinical follow-up after tissue diagnosis in the current literature [7,11]. However, sometimes PASH presents as a significant breast asymmetry or a rapidly growing breast mass, and surgical excision can be performed [10,12]. Surgical excision should be done with negative margins to avoid recurrence. However far, wide excision is not needed because PASH is not malignant. Despite surgery with negative surgical margins, recurrence after surgery can be seen at rates of up to 22% [2,10,13]. PASH recurrences are benign and can be managed with re-excision. PASH has not been shown to increase the risk of breast cancer or to be a premalignant marker [4]. However, PASH may coexist with malignant lesions with suspicious imaging findings requiring further investigation [14].
Pruthi et al. stated a patient with a painful, growing mass with PASH with estrogen receptor positivity benefited from the selective estrogen receptor antagonist tamoxifen treatment [15]. However, it was revealed that the mass did not disappear despite the shrinkage in the continuation of the hormone therapy and that it started to grow again with the completion of the hormone therapy. In our study, none of the patients used tamoxifen. While progression was observed in only one patient (12.5%) in the follow-up group, recurrence was observed in only one patient (11.1%) in the surgical group. Thus, the side effects that may occur due to the use of tamoxifen are prevented.
In the study of Ferreira et al. [16], the mean follow-up period was 27 ± 17 months, and recurrence was not observed in 7 patients who underwent surgical excision. In comparison, surgical excision was performed due to progression in one of the nine patients who underwent follow-up Wieman et al. [11]. The mean follow-up period was 39 months (0–106 months), and no progression was observed in the five patients who were followed up. Meanwhile, recurrence was observed in two (13.3%) of the 15 patients who underwent surgery, while metachronous cancer developed in two (13.3%) patients. Since these cancers were in a different quadrant and localization than PASH in the ipsilateral breast, they were considered unrelated to PASH. Yoon et al. [8] ’s study median follow-up period was 32(6–114 months), with 66 patients. While progression was observed in 3 (15%) of 20 patients in the follow-up group, recurrence was observed in 8 (17.4%) of 46 patients who underwent surgery. Recurrence was observed in 6 (15.4%) of 39 PASH patients who Powell et al. [13] applied surgical excision to all with a mean follow-up period of 4.5 years (0.6–11 years). Our study’s mean follow-up period was 55.24 ± 26.72 (13–102) months. Recurrence was seen in only 1 (10%) of 10 patients who applied surgical excision. Surgical excision was performed due to progression in 1 of 7 (14.3%) patients in the follow-up group. The fact that the results obtained did not differ despite the prolonged follow-up period, as in our study, strengthens the finding that PASH is a benign disease.
Although our retrospective design is weak, our study is one of the studies with the most prolonged follow-up period in the current literature. Unfortunately, the low number of cases prevents prospective or randomized controlled trials for PASH.
Conclusion
Our study is one of the most extended follow-up studies in the current literature for Pseudoangiomatous Stromal Hyperplasia of the Breast. It reveals that close follow-up is sufficient after the diagnosis is confirmed with clean margins by surgical excision or tissue biopsy. Therefore, Pseudoangiomatous Stromal Hyperplasia is not a risk factor for developing breast cancer.
Footnotes
Ethics statement
The Mersin University Scientific Research Ethics Committee approved the study. During the study, all procedures were carried out by the ethical rules and the principles of the Declaration of Helsinki.
Conflict of interest
The authors declare that they have no conflict of interest.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Funding sources
There are no funding sources.
Author contributions
A.C.E. and D.T. conceived and designed this study. A.C.E. collected and analyzed the data. A.C.E. and A.D. organized the manuscript. A.C.E., D.T. and A.D. reviewed the paper and revised the manuscript. All authors have read and approved the final manuscript.