Assessing the predictive value of intraductal carcinoma of the prostate (IDC-P) in determining abiraterone efficacy for metastatic hormone-sensitive prostate cancer (mHSPC) patients.

BACKGROUND: This study explored the value of intraductal carcinoma of the prostate (IDC-P) in predicting the efficacy of abiraterone treatment in metastatic hormone-sensitive prostate cancer (mHSPC) patients. METHODS: A retrospective study of 925 patients who underwent prostate biopsies to detect IDC-P was conducted, with participants divided into two cohorts. The first cohort of 165 mHSPC patients receiving abiraterone treatment was analyzed to compare therapeutic effectiveness between IDC-P positive and negative cases. Utilizing propensity score matching (PSM) to reduce bias, outcomes such as PSA response, progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival were assessed. Additionally, the second cohort of 760 mHSPC patients compared the efficacy of abiraterone with conventional hormone therapy, focusing on differences between IDC-P positive and negative individuals. RESULTS: After PSM, our first cohort included 108 patients with similar baseline characteristics. Among them, 50% (54/108) were diagnosed with IDC-P, with 22.2% (12/54) having IDC-P pattern 1 and 77.8% (42/54) with IDC-P pattern 2. While no notable difference was seen in PSA responses between IDC-P positive and negative patients, IDC-P presence linked to worse clinical outcomes (PSA-PFS: 18.6 months vs. not reached [NR], p = 0.009; rPFS: 23.6 months vs. NR, p = 0.020). Further analysis showed comparable outcomes for IDC-P pattern 1 but significantly worse prognosis for IDC-P pattern 2 (PSA-PFS: 18.6 months vs. NR, p = 0.002; rPFS: 22.4 months vs. NR, p = 0.010). Subgroup analysis revealed IDC-P pattern 2 consistently predicted poorer outcomes across patient subgroups. Remarkably, both IDC-P positive and negative patients gained more from androgen deprivation therapy with abiraterone than conventional treatment, with IDC-P negative patients showing a more significant survival advantage, supported by better hazard ratios (0.47 and 0.66). CONCLUSION: This study found that IDC-P, especially pattern 2, predicts poor prognosis in mHSPC patients on abiraterone therapy. Also, abiraterone's advantage over hormone therapy is reduced in cases with IDC-P compared to those without.

Case Report: Efficacy of Multiparameter MRI in Diagnosis of Chronic Breast Inflammation Complicated with Invasive Ductal Carcinoma and Ductal Carcinoma in situ.

Introduction: Incidental Enhancement Lesions (IELs) complicate patient management but may be detected through multiparameter MRI including dynamic contrast enhancement magnetic resonance imaging (DCE-MRI) and synthetic magnetic resonance imaging (syMRI). The multiparameter MRI model gave greater objectivity to avoid unnecessary biopsy. Case Presentation: A 60 year-old woman had a history of occasional right breast pain and a mass was identified in the right breast. A thickening in the upper quadrant of the right outer breast was found during physical examination but no mass was palpable. Breast dynamic contrast enhancement MRI and synthetic MRI were performed prior to ultrasound-guided biopsy of the right breast lesion. Resection of the right breast lesion and sentinel lymph node was performed 2 days later. Chronic inflammation, locally invasive ductal carcinoma and high-grade ductal carcinoma in situ were found by pathological examination. Discussion: Differentiation between benign and malignant breast IELs was facilitated by use of a multiparameter MRI model with DCE-MRI and syMRI, giving greater objectivity in differentiating between benign and malignant lesions.

Update of newly-recognized salivary gland neoplasms: molecular and immunohistochemical findings and clinical importance.

With the advancement of molecular testing and the routine use of immunohistochemical stains, salivary gland tumours previously categorized as adenoma or adenocarcinoma, not otherwise specified, are being reclassified with distinct diagnoses. Newly recognized benign entities include: sclerosing polycystic adenoma, keratocystoma, intercalated duct hyperplasia and adenoma, and striated duct adenoma. Newly recognized malignant salivary gland tumours include: microsecretory adenocarcinoma, sclerosing microcytic adenocarcinoma, and mucinous adenocarcinoma. Additionally, rare subtypes of mucoepidermoid carcinoma have been described, including Warthin-like and oncocytic. Understanding of intraductal carcinoma continues to evolve. Correctly distinguishing these lesions from mimickers can be crucial for appropriate patient care and prognostication, as well as future conceptualization of salivary disease.

Feasibility study of ADCs targeting TROP-2, HER2, and CD46 in Ductal Adenocarcinoma and Intraductal Carcinoma of the prostate.

BACKGROUND: Ductal Adenocarcinoma (DAC) and Intraductal Carcinoma of the Prostate (IDC-P) respond poorly to all the currently available conventional therapies. Given their accurate and efficient elimination of cancer cells, Antibody-Drug Conjugates (ADCs) have become one of the most promising anticancer treatments. However, no ADCs have so far been approved for Prostate Cancer (PCa) treatment. This study investigated TROP-2, HER2, and CD46 expression in DAC/IDC-P samples, indirectly analyzing their preliminary feasibility as therapeutic targets for future treatment of the two conditions. PATIENTS AND METHODS: We conducted a retrospective study involving 184 participants (87 DAC/IDC-P patients and 97 Prostatic Acinar Adenocarcinoma (PAC) patients with a Gleason score ≥ 8) without prior treatment between August 2017 and August 2022. Immunohistochemical staining was employed to detect the differential protein expressions of TROP-2, HER2, and CD46 in DAC/IDC-P, PAC, and normal prostate tissues. RESULTS: Compared to pure PAC tissues, TROP-2 expression was significantly higher in DAC/IDC-P and DAC/IDC-P-adjacent PAC tissues (H-score 68.8 vs. 43.8, p < 0.001, and 59.8 vs. 43.8, p = 0.022, respectively). No significant differences in HER2 expression were observed across different cancer tissues. Compared to both DAC/IDC-P-adjacent PAC and pure PAC tissues, CD46 expression was significantly higher in DAC/IDC-P tissues (42.3 vs. 28.6, p = 0.041, and 42.3 vs. 24.3, p = 0.0035, respectively). CONCLUSIONS: Herein, TROP-2 and CD46 expression was higher in DAC/IDC-P tissues than in pure PAC and normal prostate tissues. This finding implies that ADCs targeting the two proteins hold significant promise as potential future treatments for DAC/IDC-P.

Cribriform pattern 4/intraductal carcinoma of the prostate and persistent prostate-specific antigen after radical prostatectomy.

Objectives: The objective of this study is to identify the effect of cribriform pattern 4 carcinoma/intraductal carcinoma of the prostate (CC/IDCP) on persistent prostate-specific antigen (PSA) levels after robot-assisted radical prostatectomy (RARP) in patients with localized prostate cancer (PCa). Patients and Methods: This retrospective study included 730 consecutive patients with localized PCa who underwent RARP at Mie University (n = 392) and Aichi Medical University (n = 338) between 2015 and 2021. Patients with clinically metastatic PCa (cN1 and cM1) and those who received neoadjuvant and/or adjuvant therapy before biochemical recurrence were excluded. We evaluated the effects of CC/IDCP on persistent PSA levels after RARP. Persistent PSA was defined as PSA level ≥0.2 ng/mL at 1 month postoperatively and consecutively thereafter. Using factors from logistic regression analysis, models were developed to predict persistent PSA levels. Results: Approximately 6.3% (n = 46) of the patients had persistent PSA levels. Patients with biopsy CC/IDCP (bCC/IDCP) and pathological CC/IDCP (pCC/IDCP) based on RARP specimens were 11.6% (85/730) and 36.5% (267/730), respectively. Multivariate analysis of the prediction of persistent PSA levels using preoperative factors revealed that PSA density, percentage of positive cancer cores, biopsy grade group and bCC/IDCP were independent prognostic factors. Furthermore, multivariate analysis of the prediction of persistent PSA levels using postoperative factors, excluding pN1, revealed that pathological grade group, pCC/IDCP, seminal vesicle invasion and lymphovascular invasion were independent prognostic factors. In the receiver operating characteristic curve analysis for predicting persistent PSA after RARP, areas under the receiver operating characteristic curve for the model with preoperative factors, postoperative factors, including pN1, and postoperative factors, excluding pN1, were 0.827, 0.833 and 0.834, respectively. Conclusions: bCC/IDCP predicted persistent PSA after RARP in the overall population, while pCC/IDCP predicted persistent PSA only when the pN1 population was excluded. This may be useful for predicting susceptible patients with worse outcomes.

Cribriform versus Intraductal: How to Determine the Difference.

Over the years, our understanding of cribriform and intraductal prostate cancer (PCa) has evolved significantly, leading to substantial changes in their classification and clinical management. This review discusses the histopathological disparities between intraductal and cribriform PCa from a diagnostic perspective, aiming to aid pathologists in achieving accurate diagnoses. Furthermore, it discusses the ongoing debate surrounding the different recommendations between ISUP and GUPS, which pose challenges for practicing pathologists and complicates consensus among them. Recent studies have shown promising results in integrating these pathological features into clinical decision-making tools, improving predictions of PCa recurrence, cancer spread, and mortality. Future research efforts should focus on further unraveling the biological backgrounds of these entities and their implications for clinical management to ultimately improve PCa patient outcomes.

GRIN3A: A biomarker associated with a cribriform pattern and poor prognosis in prostate cancer.

Prostate cancer with a cribriform pattern, including invasive cribriform carcinoma (ICC) and/or intraductal carcinoma (IDC) is associated with a poor prognosis, and the underlying mechanisms are unclear. Therefore, we aimed to identify biomarkers for this feature. Using a radical prostatectomy cohort, we performed within-patient differential expression analyses with RNA sequencing data to compare samples with a cribriform pattern to those with non-cribriform Gleason pattern 4 (NcGP4; n=13). ACSM1, GRIN3A, PCDHB2, and REG4 were identified as differentially expressed, and validation was performed using real-time reverse transcription polymerase chain reaction (n=99; 321 RNA samples) and RNA in situ hybridization on tissue microarrays (n=479; 2047 tissue cores). GRIN3A was significantly higher expressed in cribriform pattern vs. NcGP4, when assessed within the same patient (n=27; p=0.005) and between different patients (n=83; p=0.001). Tissue cores with IDC more often expressed GRIN3A compared to ICC, NcGP4, and benign tissue (52 % vs. ≤ 32 %). When IDC and NcGP4 was compared within the same patient (173 pairs of tissue cores; 54 patients), 38 (22 %) of the tissue microarray core pairs had GRIN3A expression in only IDC, 33 (19 %) had expression in both IDC and NcGP4, 14 (8 %) in only NcGP4 and 88 (51 %) were negative in both entities (p=0.001). GRIN3A was as well associated with biochemical recurrence (log-rank, p=0.002). In conclusion, ectopic GRIN3A expression is an RNA-based biomarker for the presence of cribriform prostate cancer, particularly for IDC.

Pure Apocrine Intraductal Carcinoma of Salivary Glands: Reassessment of Molecular Underpinnings and Behavior.

BACKGROUND: Intraductal carcinoma (IDC) of the salivary glands is a confounding entity, our understanding of which continues to evolve. At least four forms have been elucidated based on histomorphology, immunophenotype, and molecular profile: (1) intercalated duct-like, S100/SOX10+ with frequent NCOA4::RET fusions; (2) oncocytic, S100/SOX10+ with TRIM33::RET, NCOA4::RET, and BRAF V600E; (3) apocrine, AR+ with PI3 kinase pathway mutations; and (4) mixed/hybrid intercalated duct-like/apocrine, with S100/SOX10+ and AR+ areas and frequent TRIM27::RET. The revelation that myoepithelial cells harbor the same fusion as luminal cells suggested that fusion-positive cases are not in situ carcinomas as previously believed. To this point, purely apocrine IDC with entirely intraductal growth has not been found to harbor fusions, but very few cases have been tested. METHODS: IDCs with pure apocrine morphology, entirely intraductal growth, and no precursor lesion (pleomorphic adenoma or sclerosing polycystic adenoma) were retrieved from the authors' archives. Several immunostains (S100, SOX10, GCDFP-15, AR, p40/SMA) and targeted next generation sequencing (NGS) panel including 1425 cancer-related genes were performed. RESULTS: Seven entirely IDC with pure apocrine type were collected. The cases arose in the parotid glands (mean, 1.9 cm) of 5 men and 2 women ranging from 51 to 84 years (mean, 69.7 years). Histologically, tumors consisted of rounded to angulated ductal cysts lined by epithelial cells with abundant finely granular eosinophilic cytoplasm and large nuclei with prominent nucleoli. Pleomorphism was mild to moderate, the mitotic rate was low, and necrosis was absent. Conventionally invasive foci or areas of intercalated duct-like morphology were not identified. In all cases, luminal cells were diffusely positive for AR and GCDFP-15 while negative for S100/SOX10, and the ducts were completely surrounded by myoepithelial cells highlighted by p40 and SMA. Molecular analysis was successful in 6 cases. Three harbored fusions: one with NCOA4::RET, another with STRN::ALK and one with both CDKN2A::CNTRL and TANC1::YY1AP1. The three fusion-negative cases all harbored HRAS mutations; additional mutations (PIK3CA, SPEN, ATM) were found in 2 of 3 cases. All patients were treated by surgery alone. Six of them are currently free of disease (follow up 12-190 months), but the case harboring NCOA4::RET developed lymph nodes metastasis in the form of a fusion-positive invasive salivary duct carcinoma. CONCLUSIONS: Purely apocrine IDC is a heterogeneous disease. A subset seems to be genetically similar to salivary duct carcinoma and may indeed represent carcinoma in situ. The other group harbors fusions, similar to other forms of IDC. Moreover, the occurrence of lymph node metastasis discredits the idea that any fusion-positive IDC with a complete myoepithelial cell layer has no metastatic potential. With the wide use of RET-and ALK-based targeted therapies, our findings further underscore the importance of fusion analysis for IDC.

Macrocystic and non-necrotic salivary duct carcinoma of the submandibular gland: A case report.

Salivary duct carcinoma (SDC) is a major malignant salivary gland tumor that usually forms a solid tumor. Non-necrotic macrocystic SDCs have rarely been reported among salivary gland tumors. A 78-year-old Japanese man with a submandibular gland tumor was evaluated radiologically, pathologically, and immunohistochemically. A multilocular lesion with a maximum size of 6 cm was radiologically observed in the left submandibular region. It had been noticed 20 years earlier. Malignant cytological result was obtained, and surgical resection was performed. Pathological examination revealed a non-necrotic, macrocystic submandibular gland tumor lined with glandular, cribriform, or papillary forms of atypical cuboidal cells. Frankly invasive components were observed in intercystic areas. Intraductal, mucoepidermoid, and secretory carcinomas were identified as pathological differential diagnoses because of their macrocystic morphology. We diagnosed SDC because there was no intraductal growth based on the lack of myoepithelial markers, diffuse immunoreactivity to gross cystic disease fluid protein15, androgen receptor, and mammaglobin and immunonegativity to S100 and p63. Postoperative positron emission tomography revealed the absence of lymph node and distant metastases. The patient was disease-free 9 months after surgery. Salivary duct carcinoma can be included in the differential diagnoses of cystic salivary gland tumors.

Clinical Management of Intraductal Carcinoma of the Prostate.

Intraductal carcinoma of the prostate (IDC-P) has emerged as a distinct entity with significant clinical implications in prostate cancer (PCa) management. Despite historically being considered an extension of invasive PCa, IDC-P shows unique biological characteristics that challenge traditional diagnostic and therapeutic settings. This review explores the clinical management of IDC-P. While the diagnosis of IDC-P relies on specific morphological criteria, its detection remains challenging due to inter-observer variability. Emerging evidence underscores the association of IDC-P with aggressive disease and poor clinical outcomes across various PCa stages. However, standardized management guidelines for IDC-P are lacking. Recent studies suggest considering adjuvant and neoadjuvant therapies in specific patient cohorts to improve outcomes and tailor treatment strategies based on the IDC-P status. However, the current level of evidence regarding this is low. Moving forward, a deeper understanding of the pathogenesis of IDC-P and its interaction with conventional PCa subtypes is crucial for refining risk stratification and therapeutic interventions.

Unveiling the Genomic Landscape of Intraductal Carcinoma of the Prostate Using Spatial Gene Expression Analysis.

Intraductal carcinoma of the prostate (IDCP) has recently attracted increasing interest owing to its unfavorable prognoses. To effectively identify the IDCP-specific gene expression profile, we took a novel approach of characterizing a typical IDCP case using spatial gene expression analysis. A formalin-fixed, paraffin-embedded sample was subjected to Visium CytAssist Spatial Gene Expression analysis. IDCP within invasive prostate cancer sites was recognized as a distinct cluster separate from other invasive cancer clusters. Highly expressed genes defining the IDCP cluster, such as MUC6, MYO16, NPY, and KLK12, reflected the aggressive nature of high-grade prostate cancer. IDCP sites also showed increased hypoxia markers HIF1A, BNIP3L, PDK1, and POGLUT1; decreased fibroblast markers COL1A2, DCN, and LUM; and decreased immune cell markers CCR5 and FCGR3A. Overall, these findings indicate that the hypoxic tumor microenvironment and reduced recruitment of fibroblasts and immune cells, which reflect morphological features of IDCP, may influence the aggressiveness of high-grade prostate cancer.

Cribiform and intraductal carcinoma in hereditary prostate cancer: clinical and pathological analysis of 20 cases.

Cribiform and intraductal carcinoma are patterns of aggressive prostate carcinoma. This study investigated the clinical and pathological features of hereditary prostate cancer. Twenty cases of hereditary prostate cancer from 11 family lines treated at the First Affiliated Hospital of Zhejiang University School of Medicine between 2016-2022 were included to summarize the clinical and pathological features by analyzing clinical information including follow up the survival of the patients and pathological features. Of the 20 hereditary prostate cancer cases, 19 were radical prostate specimens and 1 was a biopsy specimen. The mean age at diagnosis of the patients was 67.55 years and the mean PSA was 15.44 ng/ml, of which 10 cases had PSA ≥ 10 ng/ml and 5 cases had PSA ≥ 20 ng/ml. Of the 19 radical prostate specimens, Gleason cribriform pattern (Gleason grade 4) of PCa is observed in 15 cases (78.95%), and intraductal carcinoma, usually a rare form, is seen in 9 cases (47.3%). Two cases demonstrated pelvic lymph node metastasis, and 7 cases (35%) belonged to high-risk or very high-risk PCa. One case (5.26%) showed partial deletion of expression of RB1, and 13 cases (68.42%) showed deletion of expression of PTEN. Follow-up was 4-90 months, 2 cases had biochemical recurrence and 1 case died from prostate cancer. The mean age at diagnosis of this group of patients with hereditary prostate cancer was 67.55 years, the mean preoperative PSA was 15.44 ng/ml, and their histomorphology was characterized by a high percentage of intraductal carcinoma and cribriform pattern of the prostate.

Low-grade intraductal carcinoma in minor salivary glands: A case report and clinical insights.

Rationale: Low-grade intraductal carcinoma (LG-IC), is a rare malignant tumour of the salivary glands which has a very good prognosis and must be differentiated from the other types of salivary gland malignant tumours, which have a totally different behaviour and a worse prognosis. Patient Concerns: A case is presented of a 52-year-old woman who was first diagnosed and treated in another clinic in 2019 for an LG-IC in the left submandibular gland space. Two years later, she was admitted to our department with a new lesion, this time in the upper jaw lip on the left side, which also turned out to be LG-IC. Diagnosis: Magnetic resonance imaging and positron emission tomography-computed tomography were performed in order to diagnose and adequately stage the disease prior to the therapeutic intervention. Outcomes: A 6-month follow-up reveals no sign of recurrence. Takeaway Lessons: Literature on this rare histopathological entity, as well as the differential diagnosis with the other malignant lesions of the salivary glands and the frequency of metastasis, were reviewed.

Corrigendum: Radiomic machine learning and external validation based on 3.0T mpMRI for prediction of intraductal carcinoma of prostate with different proportion.

[This corrects the article DOI: 10.3389/fonc.2022.934291.].

Ductal, intraductal, and cribriform carcinoma of the prostate: Molecular characteristics and clinical management.

Prostatic acinar adenocarcinoma accounts for approximately 95% of prostate cancer (CaP) cases. The remaining 5% of histologic subtypes of CaP are known to be more aggressive and have recently garnered substantial attention. These histologic subtypes - namely, prostatic ductal adenocarcinoma (PDA), intraductal carcinoma of the prostate (IDC-P), and cribriform carcinoma of the prostate (CC-P) - typically exhibit distinct growth characteristics, genomic features, and unique oncologic outcomes. For example, PTEN mutations, which cause uncontrolled cell growth, are frequently present in IDC-P and CC-P. Germline mutations in homologous DNA recombination repair (HRR) genes (e.g., BRCA1, BRCA2, ATM, PALB2, and CHEK2) are discovered in 40% of patients with IDC-P, while only 9% of patients without ductal involvement had a germline mutation. CC-P is associated with deletions in common tumor suppressor genes, including PTEN, TP53, NKX3-1, MAP3K7, RB1, and CHD1. Evidence suggests abiraterone may be superior to docetaxel as a first-line treatment for patients with IDC-P. To address these and other critical pathological attributes, this review examines the molecular pathology, genetics, treatments, and oncologic outcomes associated with CC-P, PDA, and IDC-P with the objective of creating a comprehensive resource with a centralized repository of information on PDA, IDC-P, and CC-P.

Intraductal Carcinoma of the Prostate versus Simulants: A Differential Diagnosis Growing in Clinical Impact.

Despite its first recognition even longer ago, in the past nearly 20 years, intraductal carcinoma of the prostate has become a standard histopathologic reporting parameter conveying a strong negative prognostic factor for prostatic adenocarcinoma. When seen at biopsy, intraductal carcinoma of the prostate is associated with risk for aggressive prostatectomy outcomes, including frequently high-grade, high-stage, high-volume disease, with increased risk for recurrence and progression. Multiple organizations, including the uropathology subspecialty societies to the World Health Organization, recognize and recommend reporting the presence of intraductal carcinoma, whether sampled in "pure" form or present with concomitant invasive adenocarcinoma. Moreover, emerging scholarship relates intraductal carcinoma to higher prevalence of homologous recombination repair deficiency mutations in prostatic adenocarcinoma, whether somatic or germline, which serve as indications for approved targeted therapies. Taken together, this is a diagnosis for the histopathologist not to miss. In view of these elevated stakes and the opportunity to further precision medicine, this review details neoplastic and non-neoplastic simulants in the differential diagnosis of intraductal carcinoma of the prostate.

Identification of recurrent BRAF non-V600 mutations in intraductal carcinoma of the prostate in Chinese populations.

While BRAF alterations have been established as a driver in various solid malignancies, the characterization of BRAF alterations in prostate cancer (PCa) has not been thoroughly interrogated. By bioinformatics analysis, we first found that BRAF alterations were associated with advanced PCa and exhibited mutually exclusive pattern with ERG alteration across multiple cohorts. Of the most interest, recurrent non-V600 BRAF mutations were found in 3 of 21 (14.3 %) PCa patients demonstrating IDC-P morphology. Furthermore, experimental overexpression of BRAFK601E and BRAFL597R exhibited emergence of oncogenic phenotypes with intensified MAPK signaling in vitro, which could be targeted by MEK inhibitors. Comparison of the incidence of BRAF alterations in IDC-P between western and Chinese ancestry revealed an increased prevalence in the Chinese population. The BRAF mutation may represent important genetic alteration in a subset of IDC-P, highlighting the role of MAPK signaling pathway in this subtype of PCa. To the best of knowledge, this is the first description of non-V600 BRAF mutation in setting of IDC-P, which may in part explain the aggressive phenotype seen in IDC-P and could also bring more treatment options for PCa patients with IDC-P harboring such mutations.

Molecular complexity of intraductal carcinoma of the prostate.

Intraductal carcinoma of the prostate (IDC-P) is an aggressive subtype of prostate cancer characterized by the growth of tumor cells within the prostate ducts. It is often found alongside invasive carcinoma and is associated with poor prognosis. Understanding the molecular mechanisms driving IDC-P is crucial for improved diagnosis, prognosis, and treatment strategies. This review summarizes the molecular characteristics of IDC-P and their prognostic indications, comparing them to conventional prostate acinar adenocarcinoma, to gain insights into its unique behavior and identify potential therapeutic targets.

Treated Primary Cutaneous Malignant Melanoma With Later Metastasis Found in Clinical Presentation of Left Axilla Lymphadenopathy: A Case Report.

This case report details the rare instance of metastatic spread of cutaneous malignant melanoma to the breast in a 50-year-old female. The patient presented with a palpable axillary mass confirmed to be metastasis despite excision and closure of the primary malignancy. The mass seen in clinical and radiological presentations presented with features of complicated differentiation from a primary breast tumor. Biopsy and staining with immunohistochemical markers S100 and Sox10 played a critical role in confirming the melanocytic origin of this metastatic lesion. Breast metastases are associated with poor prognosis, and this case emphasizes the importance of in-depth evaluations for patients with a history of malignant melanoma and the need for ongoing clinical awareness in this field.