Breast Nodules Research Articles

Persistence of the Left Superior Vena Cava (PVCSG)

Persistence of the left superior vena cava (PVCSG) is a rare and benign congenital malformation. It is often asymptomatic and its discovery is in most cases fortuitous. We report the case of a patient in whom this anomaly was discovered following a monitoring assessment of a left breast nodule.45 yeas the physical examination on admission is normal. The electrocardiogram is without abnormalities. The chest x-ray showed a left middle arch in double contour. CT confirmed the diagnosis of PVCSG. Furthermore, the thoracic aorta was normal in these different segments.

Breast implant associated anaplastic large cell lymphoma detected by 18F-FDG PET/CT case report

We present a case of a 66-year-old female with a history of traumatic breast injury treated with mastectomy and subsequent bilateral breast prosthesis surgery and presenting with a suspected right breast nodule with histological confirmation of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). Subsequently, she underwent a 18F-FDG PET/CT scan that demonstrated increased focal uptakes along the perimeter of the right breast implant corresponding to several nodules. She underwent a right mastectomy with prosthesis removal. With this report, we underline the potential usefulness of 18F-FDG PET/CT in detecting BIA-ALCL.

VP03.10: Imaging and clinical profile in patients with breast nodules in occidental Amazon

VP03.10: Imaging and clinical profile in patients with breast nodules in occidental Amazon

S2960 Incidental Diagnosis of a Rare Metastatic Neuroendocrine Breast Cancer During Routine Screening Mammogram Which Eventually Revealed Primary Small Intestine Carcinoid Tumor

Introduction: Neuroendocrine neoplasms (NENs), defined as epithelial neoplasms with predominant neuroendocrine differentiation, typically occur in the pancreas, tubular gastrointestinal tract, or lung with or without secretory syndromes. Neuroendocrine breast carcinoma (NEBC) is a rare tumor which accounts for 1-2% of all invasive breast carcinoma. When NENs are found on a biopsy of a breast nodule it is considered either primary NEBC or metastatic if another primary organ is discovered. NEBC usually presents as a breast lump on exam without neuroendocrine symptoms. Therefore, making a diagnosis of NEBC prior to biopsy is difficult. We present a case of an incidentaloma discovered on routine mammography that turned out to be NEBC on biopsy and further evaluation discovered an asymptomatic primary small bowel NEN, thus confirming the breast as metastatic NEBC. Case Description/Methods: A routine mammogram in 60 yo. female revealed an abnormal 4 mm solid nodule in the right breast. A core needle biopsy found a low grade, well differentiated NEN, with positive staining for synaptophysin and chromogranin. She felt well and denied any symptoms. Medical history was notable for immune hepatitis with liver cirrhosis managed by her hepatologist. An abdominal MRI/MRCP revealed thickening in the small bowel wall consistent with a primary carcinoid tumor and demonstrated hepatic surface metastases. Plasma and 24 hr. urine 5 HIAA and chromogranin A plasma levels were normal. A lumpectomy was performed and therapy with lanreotide i.m. monthly injections begun. At 6 months follow-up, she remains asymptomatic, with stable disease. Discussion: Metastasis to the breast from a primary NEN is infrequently reported in the literature. If discovered in a patient without a history of known primary NEN in another organ, imaging is warranted to seek asymptomatic and non-secreting tumors elsewhere, as in the GI tract of our patient. No proven effective chemotherapy or RT for either primary or metastatic NEBC exists. No proven effective chemotherapy regimen exists for NENs, but therapy with long-acting somatostatin analogs are the preferred first-line option for NENs associated with several hormonal syndromes as well as for growth control in well-differentiated unresectable or metastatic gastroenteropancreatic NENs as in our case.

Breast nodule classification with two-dimensional ultrasound using Mask-RCNN ensemble aggregation

PurposeThe purpose of this study was to create a deep learning algorithm to infer the benign or malignant nature of breast nodules using two-dimensional B-mode ultrasound data initially marked as BI-RADS 3 and 4. Materials and methodsAn ensemble of mask region-based convolutional neural networks (Mask-RCNN) combining nodule segmentation and classification were trained to explicitly localize the nodule and generate a probability of the nodule to be malignant on two-dimensional B-mode ultrasound. These probabilities were aggregated at test time to produce final results. Resulting inferences were assessed using area under the curve (AUC). ResultsA total of 460 ultrasound images of breast nodules classified as BI-RADS 3 or 4 were included. There were 295 benign and 165 malignant breast nodules used for training and validation, and another 137 breast nodules images used for testing. As a part of the challenge, the distribution of benign and malignant breast nodules in the test database remained unknown. The obtained AUC was 0.69 (95% CI: 0.57–0.82) on the training set and 0.67 on the test set. ConclusionThe proposed deep learning solution helps classify benign and malignant breast nodules based solely on two-dimensional ultrasound images initially marked as BIRADS 3 and 4.

Breast myeloid sarcoma presenting as a palpable breast lump after allogeneic stem cell transplantation for acute myelomonocytic leukemia: a rare case report

BackgroundMyeloid sarcoma (MS) is a tumor secondary to myeloid leukemia that consists of immature granulocytes with or without mature granulocytes and is a rare extramedullary manifestation of acute myeloid leukemia (AML).Case presentationWe report a case of a 34-year-old woman diagnosed with AML-M4 who achieved remission after chemotherapy and received allogeneic stem cell transplantation (allo-SCT) for consolidation. Her past medical history showed that she received bilateral breast implants 7 years ago. This patient underwent ultrasound examination of the breast and multiple bilateral breast nodules were revealed that were not considered by clinicians to be concerning. Several months later, the patient’s bilateral nodules rapidly progressed to large palpable masses. Ultrasound-guided biopsy revealed diffuse infiltration of undifferentiated tumor cells and immunohistochemistry (IHC) indicated that the tumor was positive for myeloperoxidase (MPO), cluster of differentiation (CD) 34, CD43, CD68, CD117, and Ki67. The pathological diagnosis was extramedullary recurrence of AML as MS of breast. After the diagnosis, the patient received systemic chemotherapy and drugs containing cytarabine, azacitidine, and methotrexate. However, 1 year after achieving partial remission, the patient died from intracranial invasion of leukemia, brain herniation, and respiratory failure.ConclusionIt is necessary for the specialist to have a high suspicion index by careful inquiry of the patient’s medical history if a patient presents at the breast clinic with a breast tumor as the chief complaint. Combining information from the patient’s medical history with a tumor biopsy is critical for obtaining the correct diagnosis of the disease.

Diagnostic Yield of Fine Needle Aspiration in Women with Palpable Breast Nodules and Negative Mammogram and Ultrasound (BIRADS 1-2).

Diagnostic Yield of Fine Needle Aspiration in Women with Palpable Breast Nodules and Negative Mammogram and Ultrasound (BIRADS 1-2).

Three artificial intelligence data challenges based on CT and ultrasound

Purpose: The 2020 edition of these Data Challenges was organized by the French Society of Radiology (SFR), from September 28 to September 30, 2020. The goals were to propose innovative artificial intelligence solutions for the current relevant problems in radiology and to build a large database of multimodal medical images of ultrasound and computed tomography (CT) on these subjects from several French radiology centers. Materials and methods: This year the attempt was to create data challenge objectives in line with the clinical routine of radiologists, with less preprocessing of data and annotation, leaving a large part of the preprocessing task to the participating teams. The objectives were proposed by the different organizations depending on their core areas of expertise. A dedicated platform was used to upload the medical image data, to automatically anonymize the uploaded data. Results: Three challenges were proposed including classification of benign or malignant breast nodules on ultrasound examinations, detection and contouring of pathological neck lymph nodes from cervical CT examinations and classification of calcium score on coronary calcifications from thoracic CT examinations. A total of 2076 medical examinations were included in the database for the three challenges, in three months, by 18 different centers, of which 12% were excluded. The 39 participants were divided into six multidisciplinary teams among which the coronary calcification score challenge was solved with a concordance index > 95%, and the other two with scores of 67% (breast nodule classification) and 63% (neck lymph node calcifications).

Breast metastases from primary lung cancer: a retrospective case series on clinical, ultrasonographic, and immunohistochemical features.

BackgroundLung cancer metastases to the breast are less common and consequently have received much less attention in clinical practice. The purpose of this study was to provide a better understanding of clinical, ultrasonographic, and immunohistochemical features of breast metastases from primary lung cancer.MethodsThis retrospective case series included patients with breast metastases from primary lung cancer between January 2012 and December 2020. Clinical features, ultrasonographic characteristics, and immunohistochemical findings were evaluated in this analysis.ResultsIn all, 7 cases (mean ± standard deviation age: 57.4±8.3 years; range, 49–70 years) were evaluated. The maximum size of breast lesions in 6 cases ranged from 1.2 to 4.5 cm, while 1 case showed a diffused pattern. Ultrasound features of breast metastases from lung cancer were irregular (5/7, 71.4%), indistinct (6/7, 85.7%), hypoechoic (7/7, 100.0%), and parallel (6/7, 85.7%) masses without calcification. Immunohistochemical staining test was positive for thyroid transcription factor 1 (TTF-1) in all patients (7/7, 100.0%), 3 cases (3/5, 60.0%) were negative for p63, 5 cases (5/5, 100.0%) were positive for cytokeratin 7 (CK7), 4 cases (4/5, 80.0%) were positive for napsin A.ConclusionsThe ultrasonographic features of lung metastases to the breast are clinically important to understand. A known history of the primary lung cancer is of great importance when evaluating patients with a breast nodule. The presence of an ipsilateral lung cancer, breast nodule and axillary lymphadenopathy should be considered with pathological and immunohistochemical data to differentiate breast metastases from a primary breast malignancy in this setting.

Improved Inception V3 method and its effect on radiologists' performance of tumor classification with automated breast ultrasound system.

The automated breast ultrasound system (ABUS) is recognized as a valuable detection tool in addition to mammography. The purpose of this study was to propose a novel computer-aided diagnosis (CAD) system by extracting the textural features from ABUS images and to investigate the efficiency of using this CAD for breast cancer detection. This retrospective study involved 149 breast nodules [maximum diameter: mean size 18.89 mm, standard deviation (SD) 10.238, and range 5-59 mm] in 135. We assigned 3 novice readers (<3 years of experience and 3 experienced readers (≥10 years of experience to review the imaging data and stratify the 149 breast nodules as either malignant or benign. The Improved Inception V3 (II3) method was developed and used as an assistant tool to help the 6 readers to re-interpret the images. Our method (II3) achieved an accuracy of 88.6% for the final result. The 3 novice readers had an average accuracy of 71.37%±4.067% while the 3 experienced readers was 83.03%±3.371% on the first-reading. With the help of II3 on the second-reading, the average accuracy of the novice readers increased to 84.13%±1.662% and the experienced readers increased to 89.50%±0.346%.The areas under the curve (AUCs) were similar compared with linear algorithms. The mean AUC of the novice readers was improved from 0.7751 (without II3) to 0.8232 (with II3). The mean AUC of the experienced readers was improved from 0.8939 (without II3) to 0.9211 (with II3). The mean AUC for all readers improved in both the second-reading mode (from 0.8345 to 0.8722, P=0.0081<0.05). With the help of the II3, the diagnostic accuracy of the two groups were both improved, and II3 was more helpful for novice readers than for experienced readers. Our results showed that II3 is valuable in the differentiation of benign and malignant breast nodules and it also improves the experience and skill of some novice radiologists. The II3 cannot completely replace the influence of experience in the diagnostic process and will retain an auxiliary role in the clinic at present.

Correlation Analysis of Breast and Thyroid Nodules: A Cross-Sectional Study.

ObjectiveBased on physical examination, to explore the relationship between breast mass (BM) and thyroid nodule (TN) prevalence, and to further explore other related factors that affect the occurrence of BM and TN.MethodsFrom January 1, 2018, to January 1, 2021, 12,538 female subjects received breast and thyroid ultrasound examinations at the same time in the health examination center of the Affiliated Hospital of North Sichuan Medical College. Univariate analysis and multivariate logistic analysis were used to screen the relevant factors affecting TN and BM, and propensity score matching was used to further verify the results of the relationship between breast and thyroid.ResultsA total of 4975 (39.7%) of the included subjects have BM and a total of 6315 (50.4%) have TN,2557 (20.4%) had both BM and TN. The logistic regression results show that patients with TN are more likely to suffer from BM [OR = 1.185, 95% CI (1.099–1.278), p<0.0001]. In addition, age, free T4, HDL, height, BMI, systolic blood pressure, diastolic blood pressure, and albumin are independent factors affecting the occurrence of BM; patients with BM are more likely to have TN [OR = 1.180, 95% CI (1.094–1.272), p<0.0001], and age, free T3, free T4, AST, ALT, albumin, height, and BMI are independent influencing factors on the occurrence of TN. The result of propensity score matching confirmed the relationship between BM and TN.ConclusionThere is a bidirectional pathogenic relationship between BM and TN, women with BM are at increased risk of TN, and women with TN are more likely to have BM. Thyroid hormone is not only related to the occurrence of TN but also affects the occurrence of BM.

A Review of the Role of the S-Detect Computer-Aided Diagnostic Ultrasound System in the Evaluation of Benign and Malignant Breast and Thyroid Masses.

Computer-aided diagnosis (CAD) systems have attracted extensive attention owing to their performance in the field of image diagnosis and are rapidly becoming a promising auxiliary tool in medical imaging tasks. These systems can quantitatively evaluate complex medical imaging features and achieve efficient and high-diagnostic accuracy. Deep learning is a representation learning method. As a major branch of artificial intelligence technology, it can directly process original image data by simulating the structure of the human brain neural network, thus independently completing the task of image recognition. S-Detect is a novel and interactive CAD system based on a deep learning algorithm, which has been integrated into ultrasound equipment and can help radiologists identify benign and malignant nodules, reduce physician workload, and optimize the ultrasound clinical workflow. S-Detect is becoming one of the most commonly used CAD systems for ultrasound evaluation of breast and thyroid nodules. In this review, we describe the S-Detect workflow and outline its application in breast and thyroid nodule detection. Finally, we discuss the difficulties and challenges faced by S-Detect as a precision medical tool in clinical practice and its prospects.

Lupus mastitis in men

To analyze the pathophysiological aspects of lupus mastitis (LM), clinical presentation, epidemiology, radiological and histological findings, and treatment, to disseminate it to the academic community and draw attention to this pathology as one of the differential diagnoses in the management of breast lesions in males, especially in the case of breast cancer in men. A literature review was done by searching scientific studies in the PubMed / Medline, Scopus, Scielo, Embase, Web of Science, and Google Scholar databases. Relevant scientifically validated studies related to lupus mastitis in men were selected. The analysis, review and selection of articles carried out in pairs, blindly and separately, based on the reading of the title and abstract, with a third reviewer in case of disagreement. The LM should be suspect in patients known to have lupus erythematosus who present painful breast nodules associated with skin changes. However, LM can be the initial manifestation of lupus and mimic, both clinically and imaging, malignant neoplasms. The histopathological diagnostic criteria are well-established, finding mainly hyaline fat necrosis and lymphoplasmacytic infiltrate. Treatment must be drug-based as invasive procedures can exacerbate the injury. Due to physiological and anatomical aspects, this condition can appear and evolve differently in men. The knowledge of this pathology is necessary to carry out the correct approach since the non-identification of the disease and its erroneous management can lead to complications and irreversible sequelae to the patient.

Detection and recognition of ultrasound breast nodules based on semi-supervised deep learning: a powerful alternative strategy.

The successful recognition of benign and malignant breast nodules using ultrasound images is based mainly on supervised learning that requires a large number of labeled images. However, because high-quality labeling is expensive and time-consuming, we hypothesized that semi-supervised learning could provide a low-cost and powerful alternative approach. This study aimed to develop an accurate semi-supervised recognition method and compared its performance with supervised methods and sonographers. The faster region-based convolutional neural network was used for nodule detection from ultrasound images. A semi-supervised classifier based on the mean teacher model was proposed to recognize benign and malignant nodule images. The general performance of the proposed method on two datasets (8,966 nodules) was reported. The detection accuracy was 0.88±0.03 and 0.86±0.02, respectively, on two testing sets (1,350 and 2,220 nodules). When 800 labeled training nodules were available, the proposed semi-supervised model plus 4,396 unlabeled nodules performed better than the supervised learning model (area under the curve (AUC): 0.934±0.026 vs. 0.83±0.050; 0.916±0.022 vs. 0.815±0.049). The performance of the semi-supervised model trained on 800 labeled and 4,396 unlabeled nodules was close to that of the supervised learning model trained on a massive number of labeled nodules (n=5,196) (AUC: 0.934±0.026 vs. 0.952±0.027; 0.916±0.022 vs. 0.918±0.017). Moreover, the semi-supervised model was better than the average accuracy of five human sonographers (AUC: 0.922 vs. 0.889). The semi-supervised model can achieve excellent performance for nodule recognition and be useful for medical sciences. The method reduced the number of labeled images required for training, thus significantly alleviating the difficulty in data preparation of medical artificial intelligence.

Malignant adnexal cutaneous tumor of the scalp: a case report of difficult differential diagnosis between metastatic breast cancer and primary sweat gland tumor

The authors describe the case of a 71-year-old female patient who initially went to the dermatologist to assess a scalp skin tumor. This lesion was submitted to an incisional biopsy, performed by dermatologist herself, and the result of the anatomopathological examination and immunohistochemical study showed a preliminary diagnosis of metastasis of breast carcinoma. The patient had no history of breast cancer and, in view of this result, she was referred to consult with the mastologist, who carried out an investigation of breast nodules in search of the possible primary focus of the carcinoma, through imaging exams, biopsies and mammotomy, without finding any possible primary focus on the breasts. Finally, the lesion on the scalp was removed in its entirety by the plastic surgeon and a new exam of pathological anatomy and an immunohistochemical study confirmed the diagnosis of metastasis of breast carcinoma. In view of these results, the authors discuss the difficulty in diagnosing differentiation from primary or metastatic neoplasm of the scalp, with the resources currently available, until the conclusion that it was a primary carcinoma of the sweat gland.

Prediction model that combines with multidisciplinary analysis for clinical evaluation of malignancy risk of solid breast nodules.

ObjectiveFew studies have systematically developed predictive models for clinical evaluation of the malignancy risk of solid breast nodules. We performed a retrospective review of female patients who underwent breast surgery or puncture, aiming to establish a predictive model for evaluating the clinical malignancy risk of solid breast nodules.MethodMultivariable logistic regression was used to identify independent variables and establish a predictive model based on a model group (207 nodules). The regression model was further validated using a validation group (112 nodules).ResultsWe identified six independent risk factors (X3, boundary; X4, margin; X6, resistive index; X7, S/L ratio; X9, increase of maximum sectional area; and X14, microcalcification) using multivariate analysis. The combined predictive formula for our model was: Z=−5.937 + 1.435X3 + 1.820X4 + 1.760X6 + 2.312X7 + 3.018X9 + 2.494X14. The accuracy, sensitivity, specificity, missed diagnosis rate, misdiagnosis rate, negative likelihood ratio, and positive likelihood ratio of the model were 88.39%, 90.00%, 87.80%, 10.00%, 12.20%, 7.38, and 0.11, respectively.ConclusionThis predictive model is simple, practical, and effective for evaluation of the malignancy risk of solid breast nodules in clinical settings.

BDUMP: A Rare Case of Vision Loss in a Lung Transplant Recipient

Introduction Bilateral diffuse uveal melanocytic proliferation (BDUMP) is a potentially devastating rare paraneoplastic syndrome often associated with severe vision loss occurring in patients with underlying carcinoma. In approximately 50% of cases this may be the first sign of an underlying primary malignancy. First described in 1966 there are currently less then 100 cases described in the literature. Treatment of this condition includes treatment of the primary malignancy and plasmapheresis. We describe what we believe to be the first case reported in a lung transplant recipient. Case Report A 72 year old woman status post bilateral lung transplant for COPD was referred to ophthalmology due to increased vision loss for four months, one month prior to presentation she had undergone a left YAG capsulotomy. Maintenance immunosuppression included tacrolimus, mycophenolate mofetil, and prednisone. Fundus exam was remarkable for bilateral retinal pigment epithelium mottling and leopard spot fundus. Exam on the left showed edema. BDUMP was diagnosed, she was admitted to the hospital for plasmapheresis and an extensive evaluation for underlying malignancy. Remarkable laboratory studies showed a new acute kidney injury in the setting of chronic kidney disease with nephrotic range proteinuria. All tumor markers, ANA, ANCA, SPEP, and PLA2R were negative. CT of the head, chest, abdomen, and pelvis were unrevealing, PET scan showed a hypermetabolic breast nodule which was biopsied. The biopsy was consistent with ductal carcinoma in situ, and her mycophenolate was stopped. She completed 14 sessions of plasmapheresis and had improvement in her vision. Summary BDUMP, a rare condition which left untreated can lead to rapid vision loss, is associated with carcinomas of the cervix, uterus, ovary, lung, kidney, pancreas, breast, gastrointestinal tract, and Hodgkin lymphoma. While the exact pathogenesis for BDUMP has not yet been described it has been shown that these patients have a factor in the IgG fraction of serum that selectively causes melanocyte proliferation and thus plasmapheresis is an effective treatment. Patients that are immune suppressed are at an elevated risk for cancer, therefore it's highly important to keep up with health maintenance examinations in this population. Visual changes after transplant are also common, and a complete ophthalmologic examination should be completed with new onset of symptoms.

Value of Elastography Strain Ratio Combined with Breast Ultrasound Imaging Reporting and Data System in the Diagnosis of Breast Nodules

Objective To explore the value of elastography strain ratio(SR)combined with breast ultrasound imaging reporting and data system(BI-RADS-US)in the differential diagnosis of breast nodules.Methods A total of 471 breast nodules(from 471 patients)were reclassified by SR combined with BI-RADS-US.With the pathology results as gold standard,the area under the receiver operating characteristic(ROC)curve(AUC)was employed to evaluate the diagnostic performance,and the sensitivity,specificity,and accuracy were compared between the combined method and BI-RADS-US.Results Among the 471 breast nodules,180 nodules were benign and 291 were malignant.The AUC of the combined method was statistically significantly higher than that of BI-RADS-US(0.798 vs. 0.730;Z= 2.583, P= 0.010).SR,BI-RADS-US,and the combined method for diagnosing breast nodules had the sensitivity of 86.6%,99.0%,and 96.6%,the specificity of 67.2%,47.2%,and 63.3%,and the accuracy of 79.2%,79.2%,and 83.9%,respectively.The combined method increased the specificity from 47.2%(BI-RADS-US)to 63.3%(χ 2=14.25,P < 0.001),and downgraded 57.5%(42/73)benign nodules of BI-RADS category 4A to category 3.Conclusions SR combined with BI-RADS-US can improve the diagnostic performance for breast nodules.Especially,it can improve the specificity,avoiding unnecessary biopsy of breast nodules.

Randomized Controlled Trial of Breast Nodule Lysis Versus Tamoxifen for the Treatment of Mammary Gland Hyperplasia

To study the efficacy of breast nodule lysis (BNL) for the treatment of mammary gland hyperplasia (MGH). A total of 304 patients with MGH and breast pain were randomly divided into a BNL group and an oral tamoxifen (OT) group. In the BNL group (n = 156), patients were treated with BNL technique once a day for 7 consecutive days. BNL is a novel technique developed by our department, by which breast nodules can be released and breast duct can be cleared via external force and manipulation. In the OT group (n = 148), patients took oral tamoxifen 10 mg once a day for 15 consecutive days beginning 5 days after termination of the menstrual period for 3 menstrual cycles. The McGill Pain Questionnaire (MPQ) score, number and size of breast nodules pre- and post-treatment, efficacy, time to response, total treatment expenses, recurrence rate, and side effects were compared across groups. The MPQ score was significantly better in the BNL than the OT on day 7, and the total effective rate (86.54%) was significantly higher in the BNL than the OT (43.92%) on day 15. The number and size of breast nodules were decreased in the BNL compared with the OT 15 days, 3 months, and 6 months after treatment. The total treatment expenses were higher in the BNL than the OT. The recurrence rate within 6 months was lower in the BNL than the OT. There was no difference in side effects (nausea, vomiting, diarrhea, or dizziness) across groups. BNL can effectively alleviate pain and reduce the number and size of nodules with quick effect and a low recurrence rate, making it an enticing treatment for MGH.

Exploring the diagnostic value of photoacoustic imaging for breast cancer: the identification of regional photoacoustic signal differences of breast tumors.

We examined 14 benign and 26 malignant breast nodules by a handheld dual-modal PA/US imaging system and analyzed the data using the quantitative and semi-quantitative method. The PA signal spatial density and PA scores of different regions of the benign and malignant nodules were compared, and the diagnostic performances of two diagnostic methods based on PA parameters were evaluated. For both quantitative and semi-quantitative results, significant differences in the distributions of PA signals in different regions of benign and malignant breast lesions were identified. The PA parameters showed good performance in diagnosing breast cancer, indicating the potential of PAI in clinical utilization.