Metaplastic carcinoma of the breast: mammographic and sonographic findings

Metaplastic breast cancer with a unique presentation and complete response to chemotherapy: a case report

BACKGROUND

Metaplastic breast carcinomas are a rare variant group of breast carcinomas. They are usually high-grade and triple-negative tumors. They often present with large primary tumor sizes. However, the involvement of axillary lymph nodes is infrequent at the time of diagnosis. Metaplastic breast carcinomas are associated with a worse prognosis and a poorer response to chemotherapy in comparison with other non-metaplastic triple-negative breast cancers. Up until this point, there are no specific treatment recommendations for metaplastic breast carcinomas beyond those intended for invasive breast cancer in general.

CASE PRESENTATION

A 40-year-old woman complained of a palpable mass in her left axilla. On ultrasonography, the mass was solid, spindle-shaped, hypoechoic with regular borders, and exhibited decreased vascularity. At first, the mass appeared to be of a muscular origin. There was not any clinical nor ultrasonic evidence of a primary breast tumor. On magnetic resonance imaging, the axillary mass was a well-defined with regular borders, measuring 24 × 35 mm. Needle biopsy showed a spindle cell tumor with mild to moderate atypia. The subsequent surgical resection revealed a spindle cell neoplasm within a lymph node, favoring a metastatic origin of the tumor. The tumor cells lacked expression of estrogen, progesterone, and HER2 receptors. PET-CT scan indicated pathological uptake in the left breast. Accordingly, the patient was diagnosed with metaplastic breast cancer that had metastasized to the axillary lymph node. She commenced a combined chemotherapy regimen of doxorubicin and cyclophosphamide. After six treatment cycles, she underwent left modified radical mastectomy with axillary lymph node dissection. Pathological examination of the specimens revealed a total burn-out tumor in the breast due to excellent treatment response. There were no residual tumor cells. All dissected lymph nodes were free of tumor. At the one-year follow-up, the patient showed no signs of tumor recurrence.

CONCLUSION

This report sheds light on a distinctive presentation of metaplastic breast carcinoma, emphasizing the need for vigilance in diagnosing this rare and aggressive breast cancer variant. In addition, the patient's remarkable response to chemotherapy highlights potential treatment avenues for metaplastic breast cancer.

Discrepancy between Tumor Size Assessed by Full-Field Digital Mammography or Ultrasonography (cT) and Pathology (pT) in a Multicenter Series of Breast Metaplastic Carcinoma Patients

Metaplastic breast cancer (BC-Mp) presents diagnostic and therapeutic complexities, with scant literature available. Correct assessment of tumor size by ultrasound (US) and full-field digital mammography (FFDM) is crucial for treatment planning.

METHODS

A retrospective cohort study was conducted on databases encompassing records of BC patients (2012-2022) at the National Research Institutes of Oncology (Warsaw, Gliwice and Krakow Branches). Inclusion criteria comprised confirmed diagnosis in postsurgical pathology reports with tumor size details (pT) and availability of tumor size from preoperative US and/or FFDM. Patients subjected to neoadjuvant systemic treatment were excluded. Demographics and clinicopathological data were gathered.

RESULTS

Forty-five females were included. A total of 86.7% were triple-negative. The median age was 66 years (range: 33-89). The median pT was 41.63 mm (6-130), and eight patients were N-positive. Median tumor size assessed by US and FFDM was 31.81 mm (9-100) and 34.14 mm (0-120), respectively. Neither technique demonstrated superiority (p > 0.05), but they both underestimated the tumor size (p = 0.002 for US and p = 0.018 for FFDM). Smaller tumors (pT1-2) were statistically more accurately assessed by any technique (p < 0.001). Only pT correlated with overall survival.

CONCLUSION

The risk of underestimation in tumor size assessment with US and FFDM has to be taken into consideration while planning surgical procedures for BC-Mp.

Metaplastic breast cancer: an all-round multidisciplinary consensus

Metaplastic breast cancer (MpBC) is a rare and aggressive histologic subtype of breast cancer (BC) characterized by the presence of at least two cellular types, commonly epithelial and mesenchymal components. Despite growing evidence that MpBC is a unique entity, it has long been treated as a variant of nonspecial type (NST) BC. MpBC typically shows the phenotype of triple-negative breast cancer (TNBC), but compared to NST-TNBC, it is a relatively chemorefractory tumor associated with worse outcomes. Therefore, there is an urgent need to develop management guidelines specifically for MpBC to improve the prognosis of patients with early MpBC. This expert consensus aims to guide diagnosis and standardize clinical management of early MpBC among treating physicians. We provide guidance on the challenging radiological and pathological diagnosis of MpBC. Evidence on the involvement of genetic predisposition in the development of MpBC is also explored. We emphasize the importance of a multidisciplinary approach for the treatment of patients with early MpBC. The optimal surgery and radiotherapy approach is presented, as well as the opportunity offered by novel therapeutic approaches to increase treatment response in this chemoresistant subtype. Appropriate management of patients with MpBC is critical to reduce the high risk of local and distant recurrence that characterizes this disease.

Imaging Findings of Metaplastic Breast Carcinoma with Chondroid Differentiation: A Case Reports

Metaplastic carcinoma of the breast is a heterogeneous group of neoplasms with mixed epithelial and mesenchymal differentiation. Metaplastic carcinoma of the breast is a rare and aggressive malignancy, with high recurrence and metastasis. Metaplastic carcinoma with chondroid differentiation is an uncommon subtype that tends to have a relatively good prognosis than that of other subtypes. We report the imaging features of three cases of pathologically proven metaplastic carcinoma with chondroid differentiation as follows: a high-density mass with amorphous or coarse heterogeneous calcifications on mammography; a microlobulated or partially indistinct, complex cystic, and solid mass on sonography; and a relatively circumscribed or partially indistinct, irregular mass with heterogeneous T2 high-signal intensity and heterogeneous or rim enhancement with initial fast enhance ment and delayed washout on MRI.

Imaging features of adenosquamous carcinoma of the breast – A rare variant of metaplastic breast carcinoma

Adenosquamous carcinoma of the breast is a rare subtype of metaplastic carcinoma, which accounts for <1% of invasive breast malignancy. Metaplastic carcinoma is usually high grade and aggressive with typically reported benign imaging features when compared to invasive ductal carcinoma. However, the adenosquamous variant is a subtype with a more favorable prognosis. Within the literature, there is limited imaging description with case studies focusing on metaplastic carcinoma. Herein, we report seven cases of the adenosquamous subtype describing the imaging findings with correlation to clinical history and pathology. The majority of patients (n = 6) presented with palpable breast masses. One patient was identified through screening mammography. Mammographically (n = 6), tumors appeared as irregular masses. Sonographically (n = 7), tumors appeared as irregular masses ranging from solid to mixed solid/cystic masses. On MRI (n = 1), one tumor appeared as an irregular rim enhancing mass. FDG PET/CT (n = 2) and whole-body bone scan (n = 1) were also available for review. The majority of tumors were low-grade (n = 6) with only one high-grade tumor. This case series of seven patients demonstrated predominantly suspicious imaging features despite the majority being low-grade tumors.

Sonographic and pathological features of metaplastic squamous cell carcinoma of the breast: a case series

Objective

The aim of this study was to evaluate the sonographic features and to compare the sonographic findings with the pathologic features.

Methods

The sonographic and pathological features of all patients were retrospectively reviewed.

Results

All these 9 patients presented with a palpable breast mass first found by the patient before presentation. The median diameters were 3.67 cm. On two-dimensional imaging, 8 masses showed mixed echogenicity with both solid and cystic components, and only 1 mass showed hypoechoic. All the masses had irregular shapes. 1 mass had indistinct margin and 8 masses had microlobulated margins. Calcifications was seen in 1 mass. On color Doppler flow imaging, 8 masses had high vascularity with high resistance index; 5 masses had grade III blood flow signal; 3 masses had grade II blood flow signal. On histopathological examination, 5 masses were adenocarcinoma with squamous metaplasia, and 4 masses were pure SCC. On immunohistochemical staining, estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor (HER2) were negative in 5 masses. There were 2 patients with lymph node metastasis.

Conclusions

Most of the sonographic features of MSCC were mixed echogenicity with central cystic components, posterior echo enhancement, abundant vascularity with high resistance.

Radiologic Findings of a Rare Subtype of Invasive Breast Cancer with Poor Prognosis: Metaplastic Carcinoma of the Breast

BACKGROUND AND OBJECTIVES

The purpose of this study was to evaluate the mammographic, sonographic and MRI findings of metaplastic breast carcinoma.

METHODS

In this retrospective review study, we analyzed the medical files of 9600 patients who were treated for invasive breast cancers. Clinical information, histopathologic and radiologic findings of 65 patients were included in this study. All existing radiologic images and medical reports were reviewed retrospectively. Thirty-three patients had MG, 58 patients had US and 7 patients had MRI imaging results.

RESULTS

Mammographically, the most frequent presentations of MPBC were round shape, microlobulated margin and high density masses. Calcifications with or without masses were not a frequent finding. The most common sonographic findings were round shape, partially indistinct angular margin, hypoechoic and heterogeneous echo patterns and no posterior feature masses. All lesions were presented as masses rather than non-mass enhancements on magnetic resonance imaging. Features of masses had more malignant feature on MRI than other modalities in all 7 patients.

CONCLUSION

Metaplastic breast carcinoma is one of the rarest poorly differentiated invasive breast carcinomas. Interestingly, these aggressive tumors demonstrate benign or moderately malign features on imaging methods. This appearance of MPBC can cause it to be misdiagnosed as a benign breast lesion especially in young women. MPBC should be kept in mind in the differential diagnosis of large palpable breast masses. Therefore, follow-up at short intervals and/or multimodality imaging studies which include breast MRI are important for the diagnosis of MPBC.

Case Reports on Metaplastic Squamous Cell Carcinoma of the Breast and Treatment Dilemma

Metaplastic squamous cell carcinoma of the breast is a very rare form of breast cancer that consists of both glandular and nonglandular components mixed with epithelial and mesenchymal tissues. Worldwide, the incidence of this tumor is between 0.1 and 2%. Because of the rarity of this tumor and heterogeneous behavior of the tumor cells, it is difficult to establish the standard therapeutic approach. We report 2 cases of metaplastic squamous cell carcinoma of the breast in young patients with different responses to treatment strategies. The first case is a premenopausal female with metaplastic squamous cell carcinoma treated with surgery, chemotherapy, and radiotherapy, and the second case is perimenopausal metaplastic squamous cell carcinoma with sarcomatoid subtype and osteoid matrix production which progressed on chemotherapy and was treated with surgery and radiation.

A Retrospective Study of the Imaging and Pathological Features of Metaplastic Breast Carcinoma and Review of the Literature

Background

Metaplastic breast cancer (MBC) is a rare type of breast cancer, characterized histologically by the presence of two or more malignant cell types (epithelial and mesenchymal). This retrospective study aimed to review the imaging and histological features of MBC, with a review of the literature.

Material/Methods

Nineteen patients with MBC (age range, 28–75 years; mean, 55 years) underwent review of their clinical records, histopathology, immunohistochemistry, and imaging findings, which included mammography, sonography, and magnetic resonance imaging (MRI) with T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and diffusion restriction determined by the apparent diffusion coefficient (ADC) and a time-intensity curve (TIC) for signal intensity.

Results

The mammographic features of MBC were oval shaped (54.5%), with indistinct margin (45.5%), and high tumor density (72.7%), and on sonography, they were oval shaped (57.1%), with hypo-echogenic areas (85.8%). On MRI, MBC showed moderate hyper-intensity with a high signal intensity in the center of the tumor on T2WI (100%), an indistinct margin (75.0%), and rim enhancement (58.3%). Using a TIC, the early phase showed rapid enhancement, and the delay phase showed a signal plateau (91.7%). DWI showed diffusion restriction in all cases determined by the ADC. Immunohistochemistry showed negative expression of estrogen receptor (ER) (91.0%), progesterone receptor (PR) (81%), and HER2 (erbB-2) (80.0%).

Conclusions

Imaging features of MBC on mammography and ultrasound were benign. The use of T2WI MRI showed characteristic features of signal intensity using TIC curve and ADC analysis, which may support biopsy and histological analysis for definitive diagnosis.

Metaplastic carcinoma of the breast with mesenchymal differentiation (carcinosarcoma). A unique presentation of an aggressive malignancy and literature review

Metaplastic carcinoma of the breast with mesenchymal differentiation (MCMD), previously known as carcinosarcoma, is a very rare and aggressive tumor that has been recently classified as a subtype of metaplastic breast carcinoma. It accounts for 0.08%-0.2% of all breast cancers, with only a few cases reported in the literature. Histologically, MCMD is characterized by a biphasic pattern of malignant epithelial and sarcomatous components without evidence of a transition zone between the two elements. We herein describe a unique case of metaplastic carcinoma of the breast with chondrosarcomatous differentiation in a postmenopausal woman who presented with a large, rapidly growing, ulcerated, bleeding mass and signs of impending sepsis. Metaplastic breast carcinomas (MBC) are rare and aggressive tumors. They are characterized by larger size, lower rates of axillary node involvement, higher rates of triple negativity and distal metastases, earlier local recurrence and poorer survival compared with classic invasive breast cancer. Because of the rarity of MBC, the optimal treatment has not been well defined. Surgery is the main curative treatment modality since MBC has shown a suboptimal response to standard chemotherapy. Patients with MBC may be appropriate candidates for novel targeted therapies.

Imaging Findings of Metaplastic Carcinoma of the Breast with Pathologic Correlation

Objectives:

To review the imaging findings of a series of cases of metaplastic carcinoma of the breast, a rare and aggressive form of breast cancer with variable imaging features.

Materials and methods:

Retrospective review of multimodality imaging features of eleven cases of metaplastic carcinoma of the breast retrieved from a single hospital institution database. Clinical and pathologic data were also documented.

Results:

The median age of presentation was 65 years. Four cases had axillary lymphadenopathies, and two had distant metastases. An oval mass was the most common sonographic finding (7/11; 64%). Lesions displayed circumscribed/partially circumscribed margins (6/11; 55%) or non-circumscribed margins (5/11; 45%). Most lesions had a heterogeneous echo structure (9/11; 82%) and posterior acoustic enhancement (6/11; 55%). In nine patients, mammographies were available. An oval dense mass was the most common mammographic finding (5/9; 56%). The majority of cases had non-circumscribed margins (6/9; 67%), and nearly half displayed calcifications (4/9; 44%).

Conclusions:

Mammographic findings were not different from the usual features of more prevalent types of breast cancer, though the majority of metaplastic carcinoma of the breast showed possible distinctive sonographic features, such as circumscribed margins or complex echogenicity, reflecting the histologic background.

Metaplastic carcinoma of the breast: Imaging and pathological features

Metaplastic carcinoma of the breast is a rare form of breast cancer. The aim of the present study was to investigate the imaging and pathological features of metaplastic carcinoma. The features identified on mammography and sonography were retrospectively reviewed in 13 women with metaplastic carcinoma of the breast. The results from the mammographs and sonographs were additionally evaluated using immunohistochemical staining for the expression of the estrogen receptor (ER) and progesterone receptor (PR), receptor tyrosine-protein kinase erbB-2 (CerbB-2) and P53. The most common features observed in the mammographs were as follows: Irregular and oval shaped masses, 53.8 and 46.2%, respectively; spiculated and circumscribed margins, each 30.8%; and high and marginally high density masses, 69.2 and 30.8%, respectively. The most common sonography features observed were as follows: Hypoechoic masses, 84.6%; complex echogenicity, 76.9%; irregular, round and oval shaped masses, 69.2, 30.8 and 30.8%, respectively; indistinct and circumscribed margins, 53.8 and 46.2%, respectively; an abundant blood flow, 53.8%; and posterior acoustic enhancement, 61.5%. The immunohistochemical (IHC) profile for 13 patients demonstrated that ER was not expressed in 100% of patients, PR and CerbB-2 were not present in 92.3% of patients, and P53 was present in 63.6% of patients. Therefore, metaplastic carcinoma of the breast exhibits more benign IHC features compared with invasive ductal carcinoma. In addition, it may be challenging to diagnose patients that do not possess posterior acoustic enhancement or express hormone receptors from other types of breast cancer.

Metaplastic Breast Cancer: Molecular Typing and Identification of Potential Targeted Therapies at a Single Institution

INTRODUCTION

Metaplastic breast carcinoma (MBC) is a rare and aggressive histologic subtype of breast cancer comprising approximately 0.5% to 5.0% of all invasive breast cancers with a poor prognosis and limited therapeutic options.

PATIENTS AND METHODS

We investigated MBC at our institution to evaluate outcomes and investigate the molecular profile of our cohort to determine the presence of mutations for which there are targeted therapies.

RESULTS

We found our cohort to consist mainly of the matrix-producing variant (72%) with 48% having the stereotypical estrogen receptor-negative/progesterone receptor-negative/human epidermal growth factor receptor-2-negative phenotype. While the overall survival of our cohort was an average of 1679 days (4.6 years), we had a surprising number of patients with second primaries (40%) and distant metastases (40%), yet few recurrences (12%). Molecular analysis of the tumors indicated that one gene mutation, CSFIR, was significantly associated with outcome (P = .021); however, the cohort was defined by frequent mutations in ERBB4 (36%), PIK3CA (48%), and FLT3 (60%), for which there are now targeted therapies.

CONCLUSION

While surgery is the appropriate first step in the management of this aggressive malignancy, the collection of data pertaining to the use of targeted agents, although anecdotal, may provide clues to better treatment for these patients.

Metaplastic Breast Carcinoma with Unusual Presentation: Review of Three Cases

BACKGROUND

Metaplastic breast carcinoma is an uncommon type of breast cancer that usually appears as a large, fast growing breast lump.

CASE REPORT

We report 3 cases of metaplastic breast carcinoma presented at our clinic in 2014. The mean age at diagnosis was 67.3 years. 1 patient presented with a fast growing, large mass detected by herself. However, in the other 2 patients, the nodule was approximately 1.5 cm in size, not fast growing, and was detected on mammography. All 3 patients were treated surgically (2 lumpectomies and 1 mastectomy), with the final pathology of metaplastic carcinoma with chondroid mesenchymal differentiation in 2 cases and metaplastic carcinoma with myoepithelial differentiation in the 3rd case. The patients are still under adjuvant therapy.

CONCLUSIONS

Metaplastic breast carcinoma may present unusually as a non-palpable lump. This entity must be considered in any breast lump.

Metaplastic breast cancer: a comparison between the most common histologies with poor immunohistochemistry factors

Background

Metaplastic carcinoma of the breast (MCB) is a rare histological type of breast cancer. This study aimed to determine whether MCB exhibits shorter overall survival (OS) and disease-free survival (DFS) compared with other histologies that are considered unfavorable.

Methods

We retrospectively analyzed 157 clinical file records of the Mexico City-based National Institute of Cancerology and compared the clinical characteristics and treatment of 24 patients with MCB, 37 patients with triple-negative invasive lobular carcinoma (TN-ILC), 48 patients with high-grade invasive ductal carcinoma (HG-IDC), and 48 patients with triple-negative invasive ductal carcinoma (TN-IDC), paired by clinical stage and age. We performed a comparative analysis and analyzed OS and DFS using a log-rank test.

Results

In patients with MCB, the 5-year DFS was 52.1% (mean, 48.52 months; 95%: 35.32-61.72), and the 5-year OS was 72.2% (mean, 59.77 months; 95% CI: 48.55-71.00). No differences were observed in the DFS of MCB compared with each of the other histologies (MCB vs. HG-IDC, p = 0.865; MCB vs. TN-IDC, p = 0.966, and MCB vs. TN-ILC, p = 0.132). Moreover, no differences were observed when comparing the OS of MCB with that of each of the other histologies (MCB vs. HG-IDC, p = 0.246; MCB vs. TN-IDC, p = 0.255, and MCB vs. TN-ILC, p = 0.387).

Conclusions

Neither OS nor DFS differ between patients with MCB and those with other histologies with unfavorable immunohistochemical factors.

Metaplastic breast carcinomas - analysis of prognostic factors in a case series

Aim of the study

Metaplastic breast carcinomas (MBC) are a rare group of cancers, accounting for about 1% of all breast cancers. The study presents a case series of MBC patients diagnosed, treated and followed up in one healthcare center.

Material and methods

The study group comprised 18 women at the median age of 63 years. The most common carcinoma type in the study group was MBC with squamous epithelial differentiation (56%). Estrogen receptor expression was identified in one patient. No steroid or HER2 receptor expression was found in the remaining patients. We analyzed recurrence and survival rates in relation to clinical and therapeutic factors by using the Kaplan-Meier method.

Results

A significantly longer overall survival time was noted among patients treated with adjuvant radiation therapy, p = 0.018. No other factors had a significant influence on survival. Because of the small size of the study group, results obtained in the study should be treated with caution.

Nodular fasciitis in the axillary tail of the breast

Nodular fasciitis is a benign proliferation of myofibroblasts which presents clinically as a rapidly growing mass with nonspecific features on imaging and high cellular activity on histopathology. Nodular fasciitis can be mistaken for malignant fibrous lesions such as soft tissue sarcoma or breast carcinoma when located within breast tissue. This presents a problem for appropriate treatment planning as the natural history of nodular fasciitis is spontaneous regression. We present the mammographic, sonographic, computed tomography, and histopathologic characteristics of nodular fasciitis in a 68 year female initially presenting with a rapidly enlarging right axillary mass.

Breast Carcinosarcomas

OBJECTIVE

Carcinosarcomas of the breast are rare and aggressive breast tumors. The optimal treatment strategies and the classification of these difficult to diagnose tumors are not clear in the literature due to their very low incidence. In this study, we aimed to evaluate patients who were operated on for breast carcinosarcoma and discuss the current literature.

MATERIALS AND METHODS

Ten patients who were treated with a diagnosis of breast carcinosarcoma between January 2000 - March 2013 at the Izmir Bozyaka Teaching and Training Hospital General Surgery Clinics were retrospectively analyzed.

RESULTS

The mean age of the patients was 59.7 (±13.4) years. Eight patients underwent modified radical mastectomy, one patient lumpectomy and one patient breast conserving surgery + sentinel lymph node biopsy procedures. The TNM stage of patients were identified as stage 1 in 2 patients, stage 2 in 6 patients, and stage 3 in 2 patients. 60-month disease-free survival rate was 52.5% (±18.6). The overall survival rate was 53.3% (±20.5). Four patients died during follow-up.

CONCLUSION

It is reported that the prognosis of carcinosarcomas are as poor as triple negative epithelial tumors. In contrast to the literature, in our study the disease-free and overall survival rates according to stage were not different from epithelial tumors. In this regard, prospective studies including more patients are required.

Breast Carcinosarcomas

OBJECTIVE

Carcinosarcomas of the breast are rare and aggressive breast tumors. The optimal treatment strategies and the classification of these difficult to diagnose tumors are not clear in the literature due to their very low incidence. In this study, we aimed to evaluate patients who were operated on for breast carcinosarcoma and discuss the current literature.

MATERIALS AND METHODS

Ten patients who were treated with a diagnosis of breast carcinosarcoma between January 2000 - March 2013 at the Izmir Bozyaka Teaching and Training Hospital General Surgery Clinics were retrospectively analyzed.

RESULTS

The mean age of the patients was 59.7 (±13.4) years. Eight patients underwent modified radical mastectomy, one patient lumpectomy and one patient breast conserving surgery + sentinel lymph node biopsy procedures. The TNM stage of patients were identified as stage 1 in 2 patients, stage 2 in 6 patients, and stage 3 in 2 patients. 60-month disease-free survival rate was 52.5% (±18.6). The overall survival rate was 53.3% (±20.5). Four patients died during follow-up.

CONCLUSION

It is reported that the prognosis of carcinosarcomas are as poor as triple negative epithelial tumors. In contrast to the literature, in our study the disease-free and overall survival rates according to stage were not different from epithelial tumors. In this regard, prospective studies including more patients are required.

Metaplastic breast cancer: histologic characteristics, prognostic factors and systemic treatment strategies

Metaplastic breast cancer (MBC) is a rare subtype of invasive breast cancer that tends to have an aggressive clinical presentation as well as a variety of distinct histologic designations. Few systemic treatment options are available for MBC, as it has consistently shown a suboptimal response to standard chemotherapy regimens. These characteristics result in a worse overall prognosis for patients with MBC compared to those with standard invasive breast cancer. Due to its rarity, data focusing on MBC is limited. This review will discuss the clinical presentation, breast imaging findings, histologic and molecular characteristics of MBC as well as potential future research directions.

Low-grade adenosquamous carcinoma of the breast: imaging and histopathologic characteristics of this rare disease

Low-grade adenosquamous carcinoma is a rare histologic subtype of breast carcinoma that has a variable mammographic and sonographic appearance, which overlaps with both benign and malignant neoplasms. Because of its lack of unique imaging features, a diagnosis of low-grade adenosquamous carcinoma is based on histopathology. The recognition of this entity is an important consideration in the differential diagnosis of breast masses and carries implications for prognosis, which is more favorable than other types of breast carcinoma.

Management of unusual histological types of breast cancer

There is increased understanding of the heterogeneity of breast tumors, with greater emphasis now being placed on histological and molecular profiles and, in particular, their implications for prognosis and therapy. This review addresses breast cancers of unusual histological subtype with an approximate incidence ≤1%. Given the rarity of these tumors, the literature contains primarily case reports, small series, and population-based studies. Data are heterogeneous and almost entirely retrospective, frequently gathered over long time periods, in the context of changing pathological techniques and reporting. In addition, our understanding of the disease biology and therapeutic context has also evolved significantly over this time. There is often limited information about the specific therapies used and the rationale for choosing such an approach. Meaningful comparisons of treatment modalities are not feasible and it is not possible to define management guidelines. Instead, this review correlates the available information to give an impression of how each subgroup behaves-of the favored surgical technique, responses to therapy, and prognosis-as well as the emerging molecular data, highlighting new research areas for potential target in clinical trials. Each tumor subtype described represents a small but real cohort of patients with breast cancer, and although inferences may be made from this review, we are mindful of the paucity of data. The management of each patient must be considered in the context of their unique clinical presentation and correlated with the evidence-based principles that apply to more common breast cancer histologies.

Review of metaplastic carcinoma of the breast: imaging findings and pathologic features

Metaplastic carcinoma (MPC), an uncommon but often aggressive breast cancer, can be challenging to differentiate from other types of breast cancer and even benign lesions based on the imaging appearance. It has a variable pathology classification system. These types of tumors are generally rapidly growing palpable masses. MPCs on imaging can present with imaging features similar to invasive ductal carcinoma and probably even benign lesions. The purpose of this article is to review MPC of the breast including the pathology subtypes, imaging features, and imaging pathology correlations. By understanding the clinical picture, pathology, and overlap in imaging characteristics of MPC with invasive ductal carcinoma and probably benign lesions can assist in diagnosing these difficult malignancies.

Metaplastic carcinoma of the breast: multimodality imaging and histopathologic assessment

BACKGROUND

Metaplastic carcinomas are ductal carcinomas that display metaplastic transformation of the glandular epithelium to non-glandular mesenchymal tissue. Metaplastic carcinoma has a poorer prognosis than most other breast cancers, so the differential diagnosis is important. Although many clinical and pathologic findings have been reported, to our knowledge, few imaging findings related to metaplastic carcinoma have been reported.

PURPOSE

To investigate whole-breast imaging findings, including mammography, sonography, MRI, and pathologic findings, including immunohistochemical studies of metaplastic carcinomas of the breast.

MATERIAL AND METHODS

We analyzed 33 cases of metaplastic carcinoma between January 2001 and January 2011. Mammography, ultrasonography, and MRI were recorded retrospectively using the American College of Radiology (ACR) breast imaging reporting and data system (BI-RADS) lexicon. Immunohistochemical studies of estrogen receptor (ER), progesterone receptor (PR), p53, and C-erbB-2 were performed.

RESULTS

The most common mammographic findings were oval shape (37%), circumscribed margin (59%), and high density (74%). The most common sonographic findings were irregular shape (59.4%), microlobulated margin (41%), complex echogenicity (81%), parallel orientation (97%), and posterior acoustic enhancement (50%). Axillary lymph node metastases were noted for 25% of the sonographic examinations. On MRI, the most common findings of margin and shape were irregularity (57% and 52.4%, respectively). High signal intensity was the most common finding on T2-weighted images (57%). Immunohistochemical profile was negative for ER (91%, 29/32) and PR (81%, 26/32).

CONCLUSION

Metaplastic carcinomas might display more benign features and less axillary lymph node metastasis than IDC. High signal intensity on T2 MRI images and hormone receptor negativity would be helpful in differentiating this tumor from other breast cancers.

Spindle Cell Metaplastic Breast Carcinoma with Leiomyoid Differentiation: A Case Report

BACKGROUND: Metaplastic carcinoma of the breast is a rare but distinct entity within the group of undifferentiated invasive carcinomas. This entity accounts for less than 0.5% of all breast cancers and contains elements of epithelial (ductal), mesenchymal, and intermediate forms of differentiation. Of these metaplastic carcinomas, there have been reports of chondroid, squamous, osseous, and spindle differentiation. CASE REPORT: We describe the clinical course of a 52-year-old female patient with an unusual histopathology of a spindle cell carcinoma of the breast, discuss the literature, and recommend an approach to diagnosis and treatment. The patient initially presented to an outside hospital with a rapidly growing breast mass that was originally diagnosed as a malignant phylloides tumor. She presented 11 months after the primary treatment with a local subcutaneous relapse. She later developed a local relapse of her metaplastic carcinoma in the chest wall. Extensive histopathological analysis lead to the diagnosis of a spindle cell metaplastic breast carcinoma with leiomyoid differentiation, which has not been described previously. CONCLUSIONS: Overlap in morphology can lead to a misinterpretation or underdiagnosis of metaplastic carcinomas. However, the prognosis is similar to more common types of breast adenocarcinoma.

Diagnostic utility of snail in metaplastic breast carcinoma

Metaplastic breast carcinoma (MBC) is a rare subtype of breast cancer characterized by coexistence of carcinomatous and sarcomatous components. Snail is a nuclear transcription factor incriminated in the transition of epithelial to mesenchymal differentiation of breast cancer. Aberrant Snail expression results in lost expression of the cell adhesion molecule E-cadherin, an event associated with changes in epithelial architecture and invasive growth. We aimed to identify the utility of Snail, and of traditional immunohistochemical markers, in accurate MBC classification and to evaluate clinicopathologic characteristics and outcome.

We retrospectively reviewed 34 MBC cases from January 1997 to September 2007. The control group contained 26 spindle cell lesions. Immunohistochemistry used Snail, p63, epidermal growth factor receptor (EGFR), OSCAR, and wide spectrum cytokeratin (WS-KER). Negative was a score less than 1%. We found that Snail and EGFR are sensitive (100%) markers with low specificity (3.8% and 19.2%) for detecting MBC. p63 and WS-KER are specific (100%), with moderate sensitivity (67.6% and 76.5%); OSCAR is sensitive (85.3%) and specific (92.3%). A combination of any 2 of the p63, OSCAR, and WS-KER markers increased sensitivity and specificity. MBCs tended to be high-grade (77%), triple negative (negative for estrogen receptor, progesterone receptor, and HER2) [27/33; 81.8%], and carcinomas with low incidence of axillary lymph node involvement (15%), and decreased disease-free [71% (95%CI: 54%, 94%) at 3 yrs.) and overall survival. A combination of p63, OSCAR and WS-KER are useful in its work-up. On the other hand, Snail is neither a diagnostic nor a prognostic marker for MBC.

Clinicopathologic features and outcomes of metaplastic breast carcinoma: comparison with invasive ductal carcinoma of the breast

PURPOSE

Metaplastic breast carcinoma (MBC) is rare. Its clinicopathologic features and prognosis are uncertain. The aim of this study was to evaluate the clinicopathologic characteristics and outcomes in comparison with invasive ductal carcinoma (IDC).

MATERIALS AND METHODS

We reviewed the data of 29 patients with MBC and 4,851 patients with IDC, who received surgery at Yonsei University Severance Hospital between 1980 and 2008. Various clinicopathologic features, recurrence free, and overall survival were investigated and compared to each other.

RESULTS

Stage IV cases at diagnosis were more common in MBC (10.3%) than in IDC (0.9%). The incidence rates of triple negative breast cancer (TNBC) were significantly higher in MBC (84.0%) than in IDC (20.1%). Larger tumors (> 2 cm) and lower tendency of axillary metastasis were frequently observed in MBC. Only one of 24 preoperative core needle biopsies (CNB) correctly diagnosed MBC. There was no significant difference in survival between the two groups.

CONCLUSION

MBC was characterized by a higher incidence of TNBC, larger tumor size, and lower tendency of axillary metastasis, and was difficult to diagnose with CNB. Although the incidence of stage IV disease at diagnosis was higher in MBC, the survival rates of stage I-III were comparable to those of IDC.

Imaging differences in metaplastic and invasive ductal carcinomas of the breast

OBJECTIVE

The purpose of this study was to compare the imaging features of metaplastic breast carcinoma with those of invasive ductal carcinoma.

MATERIALS AND METHODS

Women diagnosed on preoperative mammography or sonography with metaplastic breast carcinoma and T-stage matched invasive ductal carcinoma of the breast from a single pathology database were included in the study. Clinical and pathologic information on all metaplastic cancers was documented. Mammography and sonography variables were recorded using the BI-RADS lexicon. Groups were compared using Fisher's exact test, the chi-square test, or Wilcoxon's rank sum test, as appropriate.

RESULTS

Forty-three patients diagnosed with metaplastic carcinoma were matched to 43 patients with ductal carcinoma by tumor T stage. Patients with metaplastic carcinoma were younger (median, 46 vs 53 years, p = 0.048) than those with ductal carcinoma. Mammographically, metaplastic carcinomas were less frequently irregular in shape (16% vs 74%, p < 0.0001) and less frequently showed microlobulated or spiculated margins (19% vs 56%, p = 0.0008) and calcifications (25% vs 51%, p = 0.02) when compared with ductal carcinomas. Sonographically, metaplastic carcinomas were less frequently irregular in shape (27% vs 69%, p = 0.001) and less frequently showed angular margins (9% vs 49%) and posterior acoustic shadowing (9% vs 49%, p < 0.0001).

CONCLUSION

Characteristic malignant imaging features, including irregular shape, spiculated margins, segmentally distributed pleomorphic calcifications, and posterior acoustic shadowing, are uncommon in metaplastic carcinomas. These carcinomas tend to show more benign imaging features, such as round or oval shape with circumscribed margins, when compared with ductal carcinomas.

Metaplastic breast carcinoma with extensive osseous differentiation: a case report

We present a case of a 77-year-old female who had a metaplastic breast carcinoma with extensive osseous differentiation. Her mammogram showed a largely calcified mass, but the pathology revealed that the calcification was ossification. The radiologic differentiation between an osteoid matrix and a dense calcification is discussed. Radiologic and pathologic correlation is also provided.

Imaging Features of Metaplastic Carcinoma with Chondroid Differentiation of the Breast

OBJECTIVE

The purpose of this study was to evaluate the imaging features--including the mammographic, sonographic, MRI, and bone scintigraphic findings--in 12 patients with metaplastic carcinoma with chondroid differentiation of the breast and to correlate the imaging findings with the pathologic features.

CONCLUSION

Metaplastic carcinoma with chondroid differentiation of the breast manifests as a palpable mass and should be included in the differential diagnosis of a large indistinct highdensity mass with amorphous or coarse calcifications on mammography and a relatively circumscribed complex echoic mass with posterior enhancement on sonography. A relatively circumscribed mass with a nonenhancing T2 intermediate- to high-signal-intensity internal component on MRI and an area of intense uptake of 99mTc methylene diphosphonate (MDP) on bone scintigraphy might be useful in suggesting the diagnosis of metaplastic carcinoma with chondroid differentiation.

Characteristics and Treatment of Metaplastic Breast Cancer: Analysis of 892 Cases from the National Cancer Data Base

BACKGROUND

Metaplastic breast cancer (MBC) is characterized by various combinations of adenocarcinoma, mesenchymal, and other epithelial components. It was officially recognized as a distinct pathologic diagnosis in 2000. With few published reports, we hypothesized that MBC may have markedly different characteristics at presentation than typical infiltrating ductal carcinoma (IDC) and may be managed differently.

METHODS

Data from patients with MBC and IDC reported to the National Cancer Database from January 2001 through December 2003 were reviewed for year of diagnosis, patient age, race/ethnicity, tumor size, nodal status, American Joint Committee on Cancer (AJCC) stage, tumor grade, hormone receptor status, and initial treatment, and were analyzed statistically by the Pearson chi(2) test.

RESULTS

A total of 892 patients with MBC and 255,164 patients with IDC were identified. The group with MBC was older (mean age, 61.1 vs. 59.7 years; P = .001), had a significantly increased proportion of African American (14.1%, 126 of 892, vs. 10.2%, 25,900 of 255,164; odds ratio [OR], 1.455, P = .001) and Hispanic patients (5.5%, 49 of 892 vs. 3.9%, 9,947 of 255,164; OR, 1.817, P = .001), had fewer T1 tumors (29.5% vs. 65.2%), more N0 tumors (78.1% vs. 65.7%, OR, .5, P = .001), more poorly or undifferentiated tumors (67.8% vs. 38.8%), and fewer estrogen receptor-positive tumors (11.3% vs. 74.1%, OR, 22.4, P = .001) than the IDC group. Patients with MBC were treated with breast-conserving surgery less frequently than patients with IDC (38.5% vs. 55.8%, OR, 2.0, P = .001) because of the larger tumor size. Chemotherapy was used more often for patients with MBC (53.4% vs. 42.1%, OR, 1.6, P = .001) because of more advanced AJCC stage.

CONCLUSIONS

MBC is a rare tumor with different characteristics than IDC: it presents with larger tumor size, less nodal involvement, higher tumor grade, and hormone receptor negativity. Patients with MBC are treated more aggressively than IDC (more often with mastectomy and chemotherapy) because of a higher stage at presentation, but are being treated by the same principles as IDC. Follow-up will determine the long-term results of the current treatment.

[Metaplastic carcinoma of the breast: magnetic resonance and radiophatologic correlation]

OBJECTIVES

To review our radiological experience in metaplastic carcinoma together with the clinical and histopathologic findings.

METHODS AND MATERIALS

Eight cases of histologically confirmed metaplastic carcinoma of breast were reviewed. Imaging findings from US, mammography and MRI, and immunohistochemistry results from preoperative biopsy were assessed. Conventional prognostic factors, chondral differentiation markers, striated and straight muscle markers, neural markers, cytokeratin, vimentin and intermediate filaments were determined.

RESULTS

Eight patients aged ranged from 41-72 years. Metaplastic carcinoma presented as a palpable nodule in five cases, as a nipple retraction in ones case, and was discovered as an incidental mammographic finding in two. Mammographic appearance was a round, high-density nodule, measuring 10-50 mm, with variable margins in seven patients. One had architectural distortion. In three there were calcifications. Skin and nipple retraction appeared in one. On sonographic examination nodules were ill defined and showed low heterogeneous echogenicity. On MRI, T2-weighted images showed a relatively well-defined mass with high signal intensity. In the dynamic study, all showed contrast uptake, with signal-time intensity curves similar to those of infiltrating carcinoma of the breast. Histopathologic study found one squamous-cell, one sarcomatous, three chondroid, one giant-cell, one spindle-cell, and one acantholytic carcinoma, all of which were of high histologic grade.

CONCLUSIONS

Metaplastic carcinoma should be included in the differential diagnosis of a nodule presenting with high density and variable margins on mammography, low heterogeneous echogenicity and ill defined margins on sonography, and hyperintense at T2 with malignant enhancement at MR. Immunohistochemical assessment is mandatory for the final diagnosis. The radiologist can suggest this particular subtype of tumour.

Metaplastic Breast Carcinoma with Osseous Differentiation: A Case Report

Metaplastic breast carcinoma is a rare entity with the distinguishing feature of having epithelial and mesenchymal tissue types incorporated within one tumor. This is a case report of a patient found to have a rare metaplastic breast carcinoma with prominent osseous differentiation. Radiologic and pathologic correlation is provided.

Cytomorphology of Rare Malignant Tumors of the Breast

This article reviews cytomorphology of rare malignant tumors of the breast: squamous carcinoma, metaplastic carcinoma, adenoid cystic carcinoma, apocrine carcinoma, secretory carcinoma, lipid-rich carcinoma, and carcinoma with choriocarcinomatous features. It is important to bear in mind the cytomorphology and diagnosis of rare malignant tumors of the breast in analysis of breast fine needle aspiration smears. Although rare, these malignant tumors can be diagnosed by the cytomorphological characteristics, and should be included in the differential diagnoses of breast neoplasms.

Metaplastic breast carcinoma: clinical–pathologic characteristics and HER2/neu expression

BACKGROUND

Metaplastic breast carcinomas (MBC) are rare primary breast malignancies characterized by the co-existence of carcinoma with non-epithelial cellular elements. They can be classified as monophasic spindle cell (sarcomatoid) carcinoma, biphasic carcinosarcoma, adenocarcinoma with divergent stromal differentiation (osseous, chondroid and rarely rhabdoid) as well as adenosquamous and pure squamous cell carcinomas. There is a paucity of information on clinically relevant pathologic features and clinical outcomes for these rare tumors. The aim of this study was to review the pathologic features and clinical outcomes of all cases of MBC seen at a single institution between 1971 and 2000.

METHODS

A computerized search of the Queen Elizabeth II Health Sciences Center (QEII HSC) surgical pathology files was performed for the years 1971-2000. Tumor blocks from identified cases were reviewed and immunohistochemistry was performed for estrogen and progesterone receptors (ER/PR), HER2/neu protein overexpression and cytokeratin profile. Clinical outcome information was obtained from hospital files and telephone contact with treating physicians.

RESULTS

Twenty-six (26) cases were retrieved with only one case identified before 1990. All tumors were high grade with a median tumor size of 3.7 cm (range 1.4-9.5 cm). Thirteen cases had lymph node dissections available for evaluation, with 4 demonstrating nodal metastases. Five of 26 cases were ER positive within the adenocarcinomatous component, only two of which also expressed PR. Associated ductal carcinoma in situ (DCIS) was present in 11 cases. HER2/neu over-expression was seen in only one (1/26) adenosquamous carcinoma (3 + membranous staining of the malignant glandular component). At 23 months median follow-up, disease free survival (DFS) for the entire group was 53%.

CONCLUSIONS

Although a rare breast cancer subtype, MBC is of considerable interest due to its pathological heterogeneity and differences in clinical behavior compared to typical breast carcinomas. Increasing pathologic recognition of MBC as a discrete entity is suggested by the number of MBC diagnoses in the last decade compared to previous years. The poor DFS associated with MBC suggests that further research exploring mechanisms of carcinogenesis and identifying clinically relevant prognostic factors is needed to direct optimum clinical care. Importantly, MBC variants appear to rarely overexpress the HER2/neu oncoprotein.

MRI of Metaplastic Carcinoma of the Breast

OBJECTIVE

The purpose of our study was to describe the MRI findings of metaplastic carcinoma of the breast and to compare those findings with underlying histopathologic features.

CONCLUSION

Metaplastic carcinoma of the breast shows high signal intensity on T2-weighted MRI. This finding is related to the necrotic component of the tumor and may be useful for preoperative diagnosis of metaplastic carcinoma of the breast, although it must be differentiated from mucinous carcinoma and, less frequently, necrotic infiltrating ductal carcinoma.

Metaplastic breast cancer

Metaplastic breast carcinoma is uncommon and constitutes less than 5% of all breast cancers. The cancerous epithelium becomes non-glandular through metaplastic differentiation. There are various subtypes and the extent to which this process occurs varies. A case of a 52-year-old female patient is reported and the published literature is reviewed.

Spindle cell carcinoma of the breast: a case series of a rare histological subtype

AIM

Spindle cell carcinoma (SpCC) represents <0.5% of breast cancers. We report the 15-year experience of SpCC at the Nottingham Breast Unit.

METHODS

Histopathology and case notes of metaplastic carcinomas with predominant spindle cell differentiation were analysed for patient demographics, tumour pathology, c-erb B-2 oestrogen (ER) and progesterone (PR) receptor status and radiology. Treatment, recurrence and survival rates were also analysed.

RESULTS

Nineteen patients with SpCC were identified. The median age was 68 years (range 27-92). Large ill-defined mass was the only consistent radiological features suggesting SpCC. Mean tumour size was 53 mm, (range 16-200 mm). Fifteen tumours were grade 3 and four were grade 2. Six out of 15 patients with axillary surgery had positive lymph nodes (40%). All tumours were oestrogen (ER) and progesterone (PR) negative. One tumour was focally c-erb B-2 positive in the non-spindle cell component. Median Nottingham Prognostic Index was 5.2 (range 3.6-6.6). Primary treatment was surgical in 89%. Adjuvant chemotherapy was given in four cases. The median disease free interval was 7 (range 2-109) months. Twelve cases recurred (63.2%). The main sites of metastasis were the lungs (9 cases), bone (6) and liver (1). Eleven cases have died of breast cancer (58%). Median survival was 18 months (range 4-109).

CONCLUSION

SpCC is an aggressive histological type of carcinoma of the breast. Omitting node sampling may result in significant under-staging. Negative ER, PR and c-erb B-2 status limits treatment options.

Metaplastic carcinoma of the breast: clinical, mammographic, and sonographic findings with histopathologic correlation

OBJECTIVE

The purpose of this study was to investigate the mammographic and sonographic findings of metaplastic carcinoma of the breast and to correlate the radiologic features with clinical and histopathologic findings.

CONCLUSION

Metaplastic carcinoma of the breast often manifests as a rapidly growing, palpable mass that has high density on mammography and may be microlobulated on sonography. Complex echogenicity with solid and cystic components may be seen sonographically and is related to necrosis and cystic degeneration found histopathologically. Although it is a rare breast malignancy and these features are not unique, metaplastic carcinoma should be included in the differential diagnosis for breast masses with these imaging features.