Practical approach to diagnosis of bland-looking spindle cell lesions of the breast

Enhanced magnetic resonance imaging features and management principles of low-grade myofibroblastic sarcoma of the breast: a case report

Background

Low-grade myofibroblastic sarcoma (LGMS) originating from breast is rare. Existing literature comprises clinical and pathological reports, with limited information on imaging characteristics. This study reports a case of LGMS of the breast and presents its imaging characteristics, with an emphasis on those observed using contrast-enhanced magnetic resonance imaging (MRI).

Case Description

A 50-year-old patient presented with a left breast mass for 1 year. One year before the presentation, the patient had palpated a mass of approximately 1.5 cm in size in the upper part of the left breast without any obvious cause. The mass was perceived to be growing slowly. There was no relevant family history of breast conditions. Physical examination revealed a hard, ill-defined, irregularly shaped, non-tender mass of approximately 3.5 cm × 3 cm in size, with poor mobility and a close connection to the deep skin. The mammography showed a high-density mass without microcalcifications and boundary wrapping. Ultrasonography showed an oval, ill-defined hypoechoic mass. The combination of mammography and ultrasound examination results ruled out the possibility of ductal carcinoma and benign fibroepithelial tumor. On contrast-enhanced MRI, the mass exhibited heterogeneous enhancement, high signal intensity on T2-weighted imaging (T2WI), high signal intensity on diffusion-weighted imaging (DWI), and a type I time-intensity curve (TIC). A core needle biopsy (CNB) suggested a spindle cell tumor. To confirm the diagnosis, the patient underwent surgical excision, and postoperative pathology confirmed LGMS of the breast. The patient subsequently received adjuvant radiotherapy. Seven months postoperatively, bone scintigraphy suggested possible metastases.

Conclusions

LGMS of the breast exhibited a degree of malignancy on ultrasonography, mammography, and MRI, with the contrast-enhanced MRI showing a persistent enhancement pattern (type I TIC). A preoperative biopsy indicated a spindle cell tumor. Surgical excision remains the best diagnostic method. A thorough understanding of the imaging characteristics and biopsy results of this tumor type provides comprehensive information for formulating corresponding treatment plans.

Differential diagnosis of primary mesenchymal neoplasms of the breast

OBJECTIVE

While the majority of breast neoplasms originate from epithelial cells, a rare part of them originate from mesenchymal breast tissue. This study aims to present the histomorphological and clinicoradiological features of our series of primary mesenchymal breast tumors and to discuss the features of these tumors in light of the literature.

MATERIALS AND METHODS

Cases diagnosed as primary mesenchymal breast tumor in breast resection materials evaluated in our center between 2010 and 2023 were included.

RESULTS

Of the 26 tumors included, 57.7% were diagnosed as benign and 42.3% as malignant mesenchymal tumor. Cases diagnosed as benign mesenchymal tumor were hemangioma, lipoma, extra-abdominal fibromatosis, leiomyoma, angiofibroma, lipomatosis, benign fibrous histiocytoma and granular cell tumor. Histopathological study results were compatible with angiosarcoma in 5 (45.4%), undifferentiated sarcoma in 3 (27.3%), myxofibrosarcoma in 2 (18.2%) cases and rhabdomyosarcoma in 1 (9.1%) case.

CONCLUSION

Primary breast sarcomas are rarely seen compared to benign mesenchymal tumors and constitute less than 0.1% of all malignant breast tumors. When histomorphological findings suggestive of a mesenchymal tumor are observed in breast specimens, sufficient sampling should be performed to exclude a possible phyllodes tumor, and clinicoradiological findings should be examined to exclude the possibility of a metastasis.

Malignant glomus tumor of the breast: a case report

Malignant glomus tumor (MGT) is a rare mesenchymal neoplasm. It is rarely located in the breast. We present a case of a 57-year-old female patient presenting with complaints of a progressively growing mass found in her left breast. Though multiple imaging examinations have been performed, especially multimodal ultrasound examinations, an accurate diagnosis still cannot be determined. Finally, the lesion was confirmed to be a MGT of the breast by postoperative pathological diagnosis. In conclusion, MGT originating from breast is extremely rare. No such case has ever been described before. This study demonstrates the imaging characteristics of a patient with MGT of the breast in order to provide more extensive insights to consider the differential diagnosis of breast lesions.

Brain Metastases from Breast Cancer Histologically Exhibit Solid Growth Pattern with at Least Focal Comedonecrosis: A Histopathologic Study on a Monocentric Series of 30 Cases

Since there are no morphological clues capable of making a pathologist suspect a possible mammary origin of a metastatic lesion without adequate clinical information, the histologic diagnosis of brain metastasis from BC is still based on the immunohistochemical expression of mammary gland markers such as GATA-3, ERs, PgRs and HER-2. The present retrospective study aimed to select purely morphological features capable of suggesting the mammary origin of a metastatic carcinoma in the brain. The following histological features were collected from a series of 30 cases of brain metastases from breast cancer: (i) a solid growth pattern; (ii) the presence of comedonecrosis; and (iii) glandular differentiation. Our results showed that most cases histologically exhibited a solid growth pattern with at least focal comedonecrosis, producing an overall morphology closely reminiscent of mammary high-grade ductal carcinoma in situ. Although the above-mentioned morphological parameters are not strictly specific to a mammary origin, they may have an important diagnostic utility for leading pathologists to suspect a possible breast primary tumor and to include GATA-3, ERs, PgRs and HER-2 in the immunohistochemical panel.

Anaplastic lymphoma kinase-positive inflammatory myofibroblastic tumor of the breast: a case report and review of the literature

BACKGROUND

Few reports of inflammatory myofibroblastic tumor (IMT) of the breast have been published worldwide. Furthermore, primary anaplastic lymphoma kinase (ALK)-positive IMT of the breast is extremely rare. To date, only six patients with ALK-positive IMT have been reported in the literature.

CASE PRESENTATION

A 52-year-old woman underwent a medical examination, and a left breast mass was detected. She did not feel a mass in her chest. Mammography showed a focal asymmetric density at the lower outer portion of the left breast. Breast ultrasonography showed a 1.2-cm hypoechoic lesion with relatively clear boundaries and poor blood flow. Magnetic resonance imaging and computed tomography revealed a solitary heterogeneous mass in the left breast. Pathologic examination revealed a fibrosing lesion with proliferation of fibroblastic cells arranged in a storiform pattern and admixed inflammatory cells. Immunohistochemical examination showed that the tumor cells were positive for ALK. Under the preoperative diagnosis of IMT, we performed partial mastectomy with adequate margins. The postoperative diagnosis was pathologically confirmed as IMT. Immunohistochemical staining also showed overexpression of ALK-1 in the tumor. The patient had a good clinical course for 24 months postoperatively, without recurrence or metastasis.

CONCLUSIONS

IMT of the breast shows nonspecific imaging findings, making preoperative diagnosis difficult. Nevertheless, IMT has the characteristics of low-grade neoplasms with recurrence, invasion, and metastatic potential. Our report emphasizes the importance of determining a treatment plan as soon as possible based on an accurate diagnosis to improve the prognosis of this disease.

Herpesvirus entry mediator as a potential biomarker in breast cancer compared with conventional cytotoxic T‑lymphocyte‑associated antigen 4

Breast cancer (BC) is the most common cancer in women worldwide, with 2.3 million cases recorded in 2020. Despite improvements in cancer treatment, patients with BC still succumb to the disease, due to regional and distant metastases when diagnosed at later stages. Several immune checkpoint inhibitors have been approved for BC treatment, based on their expression and role in maintaining immunosurveillance against tumors. The present study aimed to evaluate the expression of 12 immune checkpoints in patients with BC, and assess their role as diagnostic and therapeutic markers. Expression levels were measured using reverse transcription-quantitative polymerase chain reaction. Among the 12 immune markers, herpesvirus entry mediator (HVEM) was found to be significantly upregulated in patients with malignant BC compared to non-malignant controls, with a relative fold change (FC) of 1.46 and P=0.012. A similar finding was observed for cytotoxic T-lymphocyte-associated antigen 4 (CTLA4; FC=1.47 and P=0.035). In addition, receiver operating characteristic curve analysis revealed that HVEM expression allowed significant differentiation between groups, with an area under the curve of 0.74 (P=0.013). Upregulation in both HVEM and CTLA4 was revealed to be significantly associated with the human epidermal growth factor receptor-2 (HER2)-enriched phenotype (FC=3.53, P=0.009 and FC=5.98, P=0.002, respectively), while only HVEM was significantly associated with the triple-negative phenotype (FC=2.07, P=0.016). Furthermore, HVEM was significantly higher in patients with grade III tumors (FC=1.88, P=0.025) and negative vascular invasion (FC=1.67, P=0.046) compared with non-malignant controls. Serum protein levels were assessed by multiplex immunoassay, and a significant increase in HVEM was detected in patients with malignant BC compared with that in non-malignant controls (P=0.035). These data indicated that HVEM may serve as a potential biomarker and target for immunotherapy, especially for certain types of BC.

Mammary Spindle Cell Proliferations on Core Needle Biopsy: Is Excision Always Necessary?

Mammary spindle cell proliferations (SCPs) encompass a wide range of lesions and can be challenging to accurately diagnose on core needle biopsies (CNBs). Most SCPs are excised for definitive diagnosis. In the era of minimally invasive therapy, some SCP may be followed conservatively. We aim to examine the spectrum of SCP diagnosed on CNB and evaluate if excision of benign/indeterminate SCP is always required. We identified patients with SCP across 3 institutions. The CNB were classified into benign, indeterminate, or malignant. Available excisional specimens were used to classify the lesion as benign or malignant. Clinical variables were reviewed. A total of 197 SCP met the inclusion criteria, including 100 (53%) CNB classified as benign, 52 (26%) indeterminate, and 36 (19%) malignant. Nine patients had excisions without a preceding CNB. Excision was performed in 47% of benign, 87% of indeterminate, and 86% malignant CNB. Of 123 excised SCP, 77 (63%) were benign, while 44 (36%) were malignant. Most benign lesions were not suspicious radiologically (67%), while indeterminate and malignant lesions were more likely to be suspicious (44% and 75%, respectively; P <0.001). Malignant lesions tended to present as larger, rapidly growing, masses. Most mammary SCP are benign (63% of excisions). Appropriate ancillary tests can safely exclude some malignant entities. We encourage narrowing down the differential diagnosis to pertinent entities based on clinical presentation, imaging, histology, immunohistochemistry, and molecular studies, if applicable. Patients with mammary SCP may be spared surgery provided accurate pathologic diagnosis and appropriate correlation with imaging and clinical data.

Effect of Interaction between Chromium(VI) with 17β-Estradiol and Its Metabolites on Breast Cancer Cell Lines MCF-7/WT and MDA-MB-175-VII: Preliminary Study

The number of factors initiating and stimulating the progression of breast cancer are constantly increasing. Estrogens are a risk factor for breast adenocarcinoma, the toxicity of which increases as a result of metabolism and interaction with other factors. Due to the presence of environmental exposure to estrogens and metalloestrogens, we investigated how interactions between estrogens and toxic chromium(VI)[Cr(VI)] affect breast cancer lines and investigated whether estrogens play a protective role. The aim of the study was to investigate the effect of 17β-estradiol and its metabolites: 2-methoxyestradiol (2-MeOE2), 4-hydroxyestradiol (4-OHE2), and 16α-hydroxyestrone (16α-OHE1) in exposure to Cr(VI) on cell viability and DNA cell damage. Two estrogen-dependent breast cancer cell lines, MCF 7/WT and MDA-MB-175-VII, were examined. In addition, the expression of Cu-Zn superoxide dismutase (SOD1) was determined immunocytochemically to elucidate the mechanism of oxidative stress. The effects of single substances and their mixtures were tested in the model of simultaneous and 7-day estrogen pre-incubation. As a result, the viability of MCF-7 and MDA-MB-175-VII cells is lowered most by Cr(VI) and least by 17β-E2. In the combined action of estrogens and metalloestrogens, we observed a protective effect mainly of 17β-E2 against Cr(VI)-induced cytotoxicity. The highest expression of SOD1 was found in MCF-7/WT cells exposed to 17β-E2. Moreover, high apoptosis was caused by both Cr(VI) itself and its interaction with 4-OHE2 and 2-MeOE2. The direction and dynamics of changes in viability are consistent for both lines.

Breast nodular fasciitis in a postmenopausal woman: A case report and review of recent literature

Nodular fasciitis (NF) is a benign soft tissue lesion that can occur anywhere in the body. Its occurrence in the breast is a rare phenomenon, but is clinically important to distinguish from a malignant tumor as they both present as lesions of the breast. In this report, we discuss a case of NF of the breast in an postmenopausal woman who presented with an asymmetry of the breast on an annual screening mammogram followed by diagnostic imaging and a core biopsy. Ultimately, excision of the lesion (1.2 cm) was the definitive treatment for this patient and histological evaluation confirmed the diagnosis of NF. Additionally, we review the most recent literature on this topic discussing the significance to better understand the characteristics and best treatment course for breast NF. Results from a review of 11 breast NF cases demonstrated that the average age at diagnosis is 49, the mean diameter of lesions was 1.33 cm, and lesions were more frequently identified in the right upper breast. The clinical features of breast NF may present similarly to that of a malignant tumor. Accurate diagnosis with immunohistochemistry staining or USP6 FISH analysis is critical to prevent misdiagnosis and overtreatment. Clinician awareness, surgical treatment, and patient education are important for best management of breast NF.

Bilateral breast desmoid-type fibromatosis, case report and literature review

BACKGROUND

Breast desmoid-type fibromatosis (BDF) is a rare mesenchymal tumor accounting for only 0.2% of solid breast tumors. It is classified as an intermediate tumor because it is locally aggressive but has no metastatic potential. Its diagnosis is often difficult because it shares many clinical and radiologic aspects with breast carcinomas and therefore relies on anatomopathological analysis which may be supplemented by genetic analysis. The treatment of BDF has considerably evolved in the past years. While surgery was the cornerstone of the management prior to the 2000s, recent data have shown the value of active surveillance (AS) from the time of diagnosis. Indeed, after 2 years of AS, the progression-free survival (PFS) of the disease is identical or superior to surgery. Moreover, spontaneous regression has been observed in 30% of patients undergoing AS. In case of disease progression, surgery can be considered on a case-by-case basis, as well as systemic treatments.

CASE DESCRIPTION

We present a case of bilateral BDF affecting a 20-year-old woman for whom the first suggested treatment was bilateral mastectomy with reconstruction. After a second opinion, the decision was revised and AS was initiated. Almost 3 years after the onset of AS, tumors have shown a continuous regression.

CONCLUSIONS

This case demonstrates the need for experience in the management of mesenchymal tumors to avoid overtreatment by mutilating surgeries which promote recurrence. Moreover, to our knowledge, very few cases of bilateral BDF have been published to date. It thus seemed relevant for us to report this rare case which supports the interest of AS for DF, as recently advised by the Desmoid Tumor Working Group guidelines.

Association of Serum 25-Hydroxyvitamin D Concentration with Breast Cancer Risk in Postmenopausal Women in the US

The association between serum 25-hydroxyvitamin D [25(OH)D] concentration and breast cancer risk in postmenopausal women is not well understood. The aim of this study was to investigate the association between serum 25(OH)D concentration and breast cancer in postmenopausal women in the United States using nationally representative sample surveys. We used the data from seven cycles of National Health and Nutrition Examination Surveys from 2001 to 2014. Participants were non-institutionalized postmenopausal women (n = 8108). In restricted cubic spline analysis, a significant, nonlinear, invert ‘U’ relationship was observed between serum 25(OH)D concentrations and breast cancer in postmenopausal women (p = 0.029). Overall, breast cancer risk was highest (OR = 1.5) between 70 nmol/L and 80 nmol/L of serum 25(OH)D concentration. Then after serum 25(OH)D 80 nmol/L concentration, the breast cancer risk declined. In multivariate-adjusted logistic regression, the risk of having breast cancer was significantly higher in serum 25(OH)D 75−˂100 nmol/L category compared to the 25(OH)D < 30 nmol/L category [OR and 95% CI: 2.4 (1.4−4.0)]. In conclusion, serum vitamin D concentrations ≥ 100 nmol/L are associated with reduced risk of breast cancer in postmenopausal women. Controlled trials are required to verify if serum 25(OH)D ≥ 100 nmol/L offers protection against breast cancer in postmenopausal women.

Identification of the most common BRCA alterations through analysis of germline mutation databases: Is droplet digital PCR an additional strategy for the assessment of such alterations in breast and ovarian cancer families?

Breast and ovarian cancer represent two of the most common tumor types in females worldwide. Over the years, several non‑modifiable and modifiable risk factors have been associated with the onset and progression of these tumors, including age, reproductive factors, ethnicity, socioeconomic status and lifestyle factors, as well as family history and genetic factors. Of note, BRCA1 and BRCA2 are two tumor suppressor genes with a key role in DNA repair processes, whose mutations may induce genomic instability and increase the risk of cancer development. Specifically, females with a family history of breast or ovarian cancer harboring BRCA1/2 germline mutations have a 60‑70% increased risk of developing breast cancer and a 15‑40% increased risk for ovarian cancer. Different databases have collected the most frequent germline mutations affecting BRCA1/2. Through the analysis of such databases, it is possible to identify frequent hotspot mutations that may be analyzed with next‑generation sequencing (NGS) and novel innovative strategies. In this context, NGS remains the gold standard method for the assessment of BRCA1/2 mutations, while novel techniques, including droplet digital PCR (ddPCR), may improve the sensitivity to identify such mutations in the hereditary forms of breast and ovarian cancer. On these bases, the present study aimed to provide an update of the current knowledge on the frequency of BRCA1/2 mutations and cancer susceptibility, focusing on the diagnostic potential of the most recent methods, such as ddPCR.

The Novel Role of Cytomorphology from Ultrasound-Guided Fine Needle Aspiration Cytology in Evaluating the Status of Prognostic Factors including Estrogen Receptor, Progesterone Receptor and HER2 in Breast Cancer

It is well established that estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2) could be regarded as prognostic factors in breast cancer. Ultrasound-guided fine needle aspiration cytology (FNAC) has revolutionized the management of cancers, providing less invasive and quick diagnostic method. There are hardly any studies on the correlation between cytomorphology and prognostic biomarkers. We retrospectively analyzed the immunohistochemistry and the fluorescence in situ hybridization of breast cancer specimens from 252 patients, who have been diagnosed as breast cancer at our hospital. Morphological features of cytology smears were scored. The relationship between cytological features and three biomarkers were analyzed. Based on this, we developed a system to predict the status of biomarkers. The results indicated that some cytological parameters, especially the features of nucleoli, were distinctively related to the makers' expression. In the novel scoring system, a cutoff of 12.0 provided a statistical discrimination for cytological grading. We concluded that cytomorphological features were associated with prognostic factors. The HR+ neoplasms showed scattered micronucleoli, while HER2+ neoplasms demonstrated centered macronucleoli. We summarized a scoring system to predict the status of three factors. This may help us to broaden the application of breast cancer cytology.

Automated Breast Volume Scanner (ABVS)-Based Radiomic Nomogram: A Potential Tool for Reducing Unnecessary Biopsies of BI-RADS 4 Lesions

Improving the assessment of breast imaging reporting and data system (BI-RADS) 4 lesions and reducing unnecessary biopsies are urgent clinical issues. In this prospective study, a radiomic nomogram based on the automated breast volume scanner (ABVS) was constructed to identify benign and malignant BI-RADS 4 lesions and evaluate its value in reducing unnecessary biopsies. A total of 223 histologically confirmed BI-RADS 4 lesions were enrolled and assigned to the training and validation cohorts. A radiomic score was generated from the axial, sagittal, and coronal ABVS images. Combining the radiomic score and clinical-ultrasound factors, a radiomic nomogram was developed by multivariate logistic regression analysis. The nomogram integrating the radiomic score, lesion size, and BI-RADS 4 subcategories showed good discrimination between malignant and benign BI-RADS 4 lesions in the training (AUC, 0.959) and validation (AUC, 0.925) cohorts. Moreover, 42.5% of unnecessary biopsies would be reduced by using the nomogram, but nine (4%) malignant BI-RADS 4 lesions were unfortunately missed, of which 4A (77.8%) and small-sized (<10 mm) lesions (66.7%) accounted for the majority. The ABVS radiomics nomogram may be a potential tool to reduce unnecessary biopsies of BI-RADS 4 lesions, but its ability to detect small BI-RADS 4A lesions needs to be improved.

Sclerosing Mesenteritis, a Rare Cause of Mesenteric Mass in a Young Adult: A Case Report

Sclerosing mesenteritis (SM) is a rare fibroinflammatory disorder that involves mesenteric adipose tissue, more frequently localized in the small intestine, with an insidious clinical presentation having symptoms related to mass effect, usually resulting in bowel obstruction, mesenteric ischemia, as well as rapid weight loss. We report a case of a 23-year-old male presenting with palpable abdominal mass, mesogastric pain, and a history of rapid weight loss, who underwent exploratory laparoscopy. A hemorrhagic and gelatinous nodular tumor mass of the mesentery was identified and the surgical procedure was converted to a laparotomic approach. Histologically, the mass was composed of a proliferation of bland-looking spindle cells with slightly eosinophilic cytoplasm and elongated normochromatic nuclei with mild nuclear atypia, haphazardly set in a collagenized stroma; fat necrosis and inflammatory cells (lymphocytes, plasma-cells, and histiocytes) were also evident. The diagnosis of sclerosing mesenteritis was made. Our case emphasizes that histology remains pre-eminent for a correct diagnosis of SM, as pre-operative radiological-based diagnosis is non-specific.

Benign myofibroblastic/epithelial lesions of the breast with minimally infiltrative margins

A minority of mixed fibro-epithelial lesions of the breast lacks both fibroadenoma and phyllodes architectural patterns and have been previously labeled with different terms, including "hamartomas", "myoid/muscular hamartomas", "benign fibroadenomatous lesions" or "stromo-epithelial lesions of the breast". This study emphasizes the clinico-pathologic features of 5 cases of mammary benign fibro(stromo)-epithelial lesions sharing as a common morphologic theme the presence of minimally infiltrative margins due to the overgrowth of the stromal component into the surrounding fibro-fatty tissue. Notably the radiological features were suspicious for malignancy in 3 out of 5 cases. The following histologic features were seen in all cases: i) an epithelial component of benign glandular structures exhibiting the morphological spectrum of fibro-cystic disease; ii) a stromal component of bland-looking spindle cell myofibroblasts (vimentin + and α-smooth muscle actin +) set in a variably fibro-myxoid stroma. The present paper contributes to widen the morphological spectrum of the benign fibro-epithelial lesions of the breast, emphasizing the possibility that some cases, exhibiting a predominant myofibroblastic stromal component and minimally infiltrative margins, may be confused with other primary spindle cell mimickers of the breast. Accordingly, we propose the descriptive term "benign myofibroblastic/epithelial lesions of the breast with minimally infiltrative margins" for these previously underrecognized lesions.

High BMI1 Expression with Low CD8+ and CD4+ T Cell Activity Could Promote Breast Cancer Cell Survival: A Machine Learning Approach

BMI1 is known to play a key role in the regulation of stem cell self-renewal in both endogenous and cancer stem cells. High BMI1 expression has been associated with poor prognosis in a variety of human tumors. The aim of this study was to reveal the correlations of BMI1 with survival rates, genetic alterations, and immune activities, and to validate the results using machine learning. We investigated the survival rates according to BMI1 expression in 389 and 789 breast cancer patients from Kangbuk Samsung Medical Center (KBSMC) and The Cancer Genome Atlas, respectively. We performed gene set enrichment analysis (GSEA) with pathway-based network analysis, investigated the immune response, and performed in vitro drug screening assays. The survival prediction model was evaluated through a gradient boosting machine (GBM) approach incorporating BMI1. High BMI1 expression was correlated with poor survival in patients with breast cancer. In GSEA and in in silico flow cytometry, high BMI1 expression was associated with factors indicating a weak immune response, such as decreased CD8+ T cell and CD4+ T cell counts. In pathway-based network analysis, BMI1 was directly linked to transcriptional regulation and indirectly linked to inflammatory response pathways, etc. The GBM model incorporating BMI1 showed improved prognostic performance compared with the model without BMI1. We identified telomerase inhibitor IX, a drug with potent activity against breast cancer cell lines with high BMI1 expression. We suggest that high BMI1 expression could be a therapeutic target in breast cancer. These results could contribute to the design of future experimental research and drug development programs for breast cancer.

PET/CT-Detected myofibroblastoma of the breast with bizarre cells: A potential diagnostic pitfall of malignancy

Myofibroblastoma (MFB) is a rare benign mesenchymal tumor usually occurring in the breast parenchyma. This tumor can present as a palpable nodule or can be incidentally detected as a nonpalpable mass on routine screening mammogram. We first report a rare case of histologically proven MFB of the breast revealed by fluoro‐deoxyglucose uptake on PET‐CT examination in a patient with a lung nodule. Tumor exhibited an unusual morphology, being predominantly composed of polygonal, epithelioid, and deciduoid‐like cells set in a myxoid stroma. The most striking feature was the multifocal presence of atypical/bizarre, mono/bi‐nucleated cells that, in addition to diffuse myxoid stromal changes, were a concern of malignancy, especially on core biopsy. The final diagnosis of MFB was achieved on surgically resected specimen and, similarly to other benign soft tissue tumors (especially leiomyoma and schwannoma/neurofibroma), the term “bizarre cell MFB of the breast” is proposed to emphasize the degenerative/reactive nature of the atypia.

Breast Shwannoma - Time to explore alternative management strategy?

Schwannoma (SCH) is a benign peripheral nerve sheath neoplasm of Schwann cell origin. It can be observed anywhere whilst the breast is uncommon site. Preliminary investigations are not entirely diagnostic and surgical excision is often required to reach a conclusion. We conducted a retrospective review in two European Breast units to know more about this rare condition. Herein, we provide a comprehensive review and we question whether the surgical approach to management can be changed.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

Wilms' Tumor 1 (WT1): A Novel Immunomarker of Dermatofibrosarcoma Protuberans-An Immunohistochemical Study on a Series of 114 Cases of Bland-Looking Mesenchymal Spindle Cell Lesions of the Dermis/Subcutaneous Tissues

Simple Summary

Dermatofibrosarcoma protuberans (DFSP) is a superficial fibroblastic spindle cell sarcoma with a high rate of local recurrence (20% to 50%) but with a low metastatic potential. DFSP is characterized by COL1A1-PDGFB gene fusion and diffuse immunohistochemical expression of CD34. This immunomarker is especially useful in distinguishing DFSP from its morphological mimickers, especially when pathologists are faced with small biopsies. Apart from CD34, there are no additional diagnostic immunomarkers for DFSP, and thus, there is the need to identify more sensitive and specific markers for this sarcoma. Recently, Wilms’ tumor 1 (WT1) has been shown to be diffusely expressed in the cytoplasm of several benign and malignant mesenchymal spindle cell lesions. Based on this background, the aim of this study is to evaluate the immunohistochemical expression of WT1 protein in a series of bland-looking spindle cell lesions of the dermis/subcutis, emphasizing its potential diagnostic role in identifying DFSP among its morphological mimickers.

Abstract

Purpose: to investigate the immunohistochemical expression and distribution of Wilms’ tumor 1 (WT1) (transcription factor produced by the tumor suppressor gene of the same name) in a series of 114 cases of bland-looking mesenchymal spindle cell lesions of the dermis/subcutaneous tissues to establish whether this immunomarker is differentially expressed in dermatofibrosarcoma protuberans (DFSP) versus its potential morphological mimickers. Methods: This retrospective multi-centric immunohistochemical study included 57 DFSP cases, 15 dermatofibromas, 5 deep fibrous histiocytomas, 8 neurofibromas, 5 spindle cell lipomas, 8 dermal scars, 6 nodular fasciitis, 5 cutaneous leiomyomas and 5 solitary fibrous tumors. Among the 57 DFSP cases, 11 were recurrent lesions; 2 non-recurrent cases exhibited an additional “fibrosarcomatous” overgrowth and 1 recurrent and 2 primary tumors contained a minority of “giant cell fibroblastoma” components. Results: Most DFSP (95% of cases) exhibited cytoplasmic staining for WT1; 11/11 residual/recurrent tumors showed diffuse and strong WT1 cytoplasmic immunoreactivity; apart from neurofibromas, WT1 expression was lacking in all the other cases studied. Conclusions: The cytoplasmic expression of WT1 may be exploitable as a complementary diagnostic immunomarker to CD34 in confirming the diagnosis of DFSP and to better evaluate the residual/recurrent tumor component.

Best Practice (Efficient) Immunohistologic Panel for Diagnosing Metaplastic Breast Carcinoma

Immunohistochemistry (IHC) plays a key role in the diagnosis of metaplastic breast carcinomas (MBCs), particularly the spindle cell variant. The most efficient immunopanel has yet to be developed. We studied the immunoprofile of 45 MBCs including 23 matrix-producing MBCs, 11 squamous cell carcinomas, 6 spindle cell carcinomas, and 5 mixed-subtypes (2 cases including spindle cell components). Representative sections from mastectomy or core biopsy specimens were subject to IHC using a list of antibodies including OSCAR, a recently developed antibody against pooled cytokeratins. The staining was interpreted as positive when >1% of tumor cells demonstrated unequivocal staining. As a result, OSCAR showed similar sensitivity to AE1/AE3 and CAM 5.2 (89.1% vs. 89.4% vs. 89.4%) for MBCs, but the former showed more diffuse pattern of staining, particularly in spindle cell carcinomas. High molecular weight cytokeratin CK14, CK5, and CK17 were positive in 91.3%, 87.2%, and 73.3% of MBCs, respectively. CK7 was much less likely to be positive in spindle cell carcinomas (37.5%) than in other variants of MBCs (97.4%). P63 and CK14 were the most useful markers for spindle cell carcinomas, positive in 87.5% and 85.7% of cases, respectively. GATA 3 was positive in 63% MBCs, and nonspecific staining for vimentin and smooth muscle actin were common. Random combination of up to 3 antibodies against keratins including p63 showed sensitivities ranging from 80.9% to 97.9%. Our results suggested the combination of OSCAR, CK14 and p63 is the most efficient panel (sensitivity 97.9%) for diagnosing MBCs.

Desmoid Type Fibromatosis of the Breast: Ten-Year Institutional Results of Imaging, Histopathology, and Surgery

Background

Desmoid type fibromatoses has proven to be a diagnostic and therapeutic challenge, as they often appear primarily as a carcinoma of the breast with a high recurrence risk.

Patients

A digital archive search was performed for the period from 2009 to the end of 2018. Inclusion criteria consisted of histological examination of at least the surgical specimen in the reference pathology department and at least a second opinion diagnosis in the reference radiology department.

Results

A total of 14 women and 1 man underwent surgery on desmoid type fibromatosis of the breast. The average patient age was 49 years (range: 22-72 years). The mean tumor size was 2.2 cm (range: 0.8-4.2 cm). The tumor was detectable in mammography in 12 out of 13 patients and in all 15 patients in sonography. MRI was performed preoperatively in 6 patients; in all of the patients, the tumor was visualized with inhomogeneous contrast enhancement. In the imaging procedures, all desmoid type fibromatoses were classified as suspicious. Performing the core biopsy, preoperative histology confirmed desmoid fibromatosis in 12 out of 15 patients. Nuclear stain for ß-catenin was positive in 7 out of 10 patients. Negative staining was found for AE1/A3 in 10 out of 10 and CD34 in 12 out of 12 patients. In all of the patients, a single-stage operation without the detection of border-forming tumor margins was performed. The follow-up interval ranged from 16 to 96 months (mean: 44.86 months, median: 43 months). In this follow-up period, no patient was diagnosed with desmoid tumor recurrence.

Conclusion

In imaging, desmoid type fibromatosis of the breast has typical malignancy-related criteria. Extensive preoperative diagnostics enable the planning of complete primary excision of the lesion and reduce the recurrence risk.