BACKGROUND: Acinic cell carcinoma (AciCC) of the breast is a rare subtype of breast cancer. It was considered a low-grade triple-negative breast cancer (TNBC) with the potential to progress or transform into a high-grade lesion because of the molecular similarities with conventional aggressive TNBC in several genetic studies. Microscopically, the coexistence of classical low-grade and high-grade triple-negative components in breast AciCC is not uncommon. However, there is a scarcity of research on the comparative histopathological and genetic aspects of both components.
METHODS: A 34-year-old woman with a nontender mass in the upper outer quadrant of the left breast was initially diagnosed with a malignant small round cell tumor (undifferentiated or poorly differentiated carcinoma) based on a preoperative biopsy, which was later identified as breast AciCC with a high-grade solid component. Left breast-conserving surgery with sentinel lymph node biopsy was performed. Microscopically, the breast AciCC consisted of a classical acinic component and a high-grade component. The latter demonstrated a solid sheet-like pattern characterized by large, round, pleomorphic or vesicular nuclei, prominent nucleoli, and frequent mitotic activities. Classical acinic architectures focally merged together to form solid nests and transited into high-grade areas. Remarkably, in the high-grade lesion, conventional immunochemical markers for breast AciCC, such as α1-antitrypsin (AAT), Lysozyme (LYS), Epithelial membrane antigen (EMA), S100 protein (S100), and cytokeratin (CK) were negative, whereas cell cycle protein D1 (cyclin D1) and vimentin showed diffuse expression. Next‑generation sequencing (NGS) revealed that 43.5% of variants were identical in both components. Furthermore, PAK5 mutation; copy number (CN) loss of CDH1, CHEK1, and MLH1; and CN gains of CDK6, HGF, and FOXP1 were identified in the high-grade lesion. The patient was treated with eight cycles of adjuvant chemotherapy (epirubicin combined with cyclophosphamide) and radiotherapy after surgery, and she is currently alive for 43 months with no metastases or recurrences.
CONCLUSIONS: This case demonstrates a comparative analysis of the histopathological and genetic characteristics of classical low-grade and high-grade components of AciCC within the same breast. This information may serve as a morphological and molecular basis for further investigation into the molecular mechanisms underlying high-grade lesions in breast AciCC.

Acinic cell carcinoma of the salivary gland (AciCC) is a low-grade carcinoma characterized by the overexpression of the transcription factor nuclear receptor subfamily 4 group A member 3 (NR4A3). AciCC has been the subject of a few molecular research projects. This study delves into AciCC\'s molecular landscape to identify additional alterations and explore their clinical implications. RNA sequencing and immunohistochemical staining for markers NR4A3/NR4A2, DOG-1, S100, and mammaglobin were utilized on 41 AciCCs and 11 secretory carcinoma (SC) samples. NR4A3 was evident in 35 AciCCs, while the residual 6 were NR4A3-negative and NR4A2-positive; SC samples were consistently NR4A3-negative. A novel fusion, PON3 exon 1- LCN1 exon 5, was detected in 9/41 (21.9%) AciCCs, exhibiting a classical histologic pattern with serous cell components growing in solid sheets alongside the intercalated duct-like component. Clinical follow-up of 39 patients over a median of 59 months revealed diverse prognostic outcomes: 34 patients exhibited no disease evidence, whereas the remaining 5 experienced poorer prognosis, involving local recurrence, lymph node, and distant metastasis, and disease-associated death, 4 of which harbored the PON3::LCN1 fusion. In addition, the HTN3::MSANTD3 fusion was recurrently identified in 7/41 AciCC cases. SC patients lacked both fusions. Immunohistochemistry uncovered differential expression of DOG-1, S100, and mammaglobin across samples, providing nuanced insights into their roles in AciCC. This study accentuates PON3::LCN1 and HTN3::MSANTD3 fusions as recurrent molecular events in AciCC, offering potential diagnostic and prognostic utility and propelling further research into targeted therapeutic strategies.

胰腺混合性腺泡导管癌是一种罕见的侵袭性胰腺癌，肿瘤中包含胰腺导管及胰腺腺泡分化2种成分。胰腺导管内混合性腺泡导管癌则更为罕见。本文报道1例发生在58岁女性胰腺导管内的混合性腺泡导管癌病例，就诊时以慢性胰腺炎伴导管扩张迁延起病。肿瘤大体沿胰腺导管乳头样生长，伴导管扩张。镜下肿瘤沿导管生长，呈乳头样息肉凸起。可见2种成分，腺泡细胞癌的成分：肿瘤实性生长，细胞具有嗜酸颗粒状胞质及明显核仁；腺癌的成分：肿瘤细胞形成腺管结构，具有细胞内外黏液。免疫组织化学染色示腺泡细胞癌成分bcl-10及糜蛋白酶阳性，导管癌成分阿辛蓝-过碘酸雪夫染色阳性；2种成分广谱细胞角蛋白及β-catenin均膜阳性，而神经内分泌标志物CD56、突触素及嗜铬粒素A均阴性；p53弱到中度阳性，Ki-67阳性指数15%。胰腺导管内的生长方式是胰腺混合性腺泡导管癌一种极为少见的生长方式，患者以非特异性胰腺炎症状慢性迁延起病，临床表现不典型，及时正确的诊断对患者的治疗和预后评估非常重要。.

暂无摘要。

Objective: To explore the effectiveness of minimally invasive surgical treatment for pancreatic acinar cell carcinoma (PACC). Methods: Six patients with PACC diagnosed in Peking University Third Hospital from January 2010 to September 2022 were retrospectively selected. Preoperative evaluation was performed on whether the lesions were eligible for surgery, including whether radical resection of liver metastases could be performed. Laparoscopic or Da Vinci robot-assisted resection was performed on six patients, and spleen retention was determined according to the original lesions and the relationship with peripheral blood vessels and tissues, while simultaneous resection was performed on cases of peripheral organ tissue invasion. The patients\' basic information, preoperative general conditions, preoperative diagnosis and tumor stage, minimally invasive surgery methods, postoperative complications, pathological results, tumor stage and follow-up data were collected and analyzed to explore the effectiveness of minimally invasive surgery. Results: Among the six patients, four were males and two were females, with the age of 25-69 years. Five patients had abdominal pain and distension before surgery, five patients had tumors located at the tail of the pancreatic body, and one patient had tumors located at the head of the pancreas. Preoperative imaging (enhanced CT and MRI) was performed to measure the tumor diameter (2.8-10.0 cm). Tumor markers were elevated in two patients before surgery, and six patients underwent surgery through laparoscopy or robotic platform. No complications such as postoperative pancreatic fistula and bleeding were clinically relevant during and after surgery. There were two cases with concurrent or heterochronous liver metastasis, two cases with lymph node metastasis and nodular metastasis, four cases with tumor invasion of surrounding organs (stomach, spleen or duodenum), and three cases with vascular cancer thrombi. The follow-up time of the six patients was 12 to 165 months, and one patient underwent three operations due to postoperative liver metastasis and residual pancreatic recurrence, and the results were satisfactory. All the six patients survived at the last follow-up. Conclusions: PACC is prone to invade the surrounding organs, and has a large tumor diameter. Radical surgery for PACC can be completed through minimally invasive surgery, and satisfactory oncology prognosis can be obtained. In addition, some PACC patients with recurrence and metastasis can still be treated by surgery.
目的： 探讨微创手术治疗胰腺腺泡细胞癌（PACC）的效果。 方法： 回顾性选择北京大学第三医院2010年1月至2022年9月确诊的6例PACC患者为研究对象。术前评估病变是否具备手术条件，包括肝脏转移病灶能否行根治性切除，对6例患者行腹腔镜或者达芬奇机器人辅助切除术，根据术中原发病灶情况以及与周围血管和组织关系决定是否保留脾脏，对于周围器官组织侵犯病例行同期切除。收集并分析患者的基本资料、术前一般情况、术前诊断和肿瘤分期、采用的微创手术方式、术后并发症、病理结果、肿瘤分期和随访等，探讨微创手术的效果。 结果： 6例患者中男4例、女2例，年龄25~69岁。5例患者术前有腹痛和腹胀，5例患者肿瘤位于胰腺体尾部，1例患者肿瘤位于胰头部。通过术前影像学（增强CT和MRI）测量肿瘤直径2.8~10.0 cm，有2例患者术前肿瘤标记物升高，6例患者均通过腹腔镜和机器人平台完成手术，术中及术后无临床相关性术后胰瘘和出血等并发症。有2例合并同时性或异时性肝转移，2例术后病理提示出现了淋巴结转移和癌结节转移，有4例肿瘤侵犯了周围脏器（胃、脾脏或十二指肠），3例提示有脉管癌栓。6例患者随访时间12~165个月，其中1例患者由于术后肝脏转移和残余胰腺再发肿瘤经历3次手术，效果满意，截至末次随访6例患者均存活。 结论： PACC肿瘤容易侵犯周围脏器，肿瘤直径较大，通过微创手术可以完成PACC 的根治性手术，经过微创手术能够取得满意的肿瘤学预后，并且部分复发和转移后的PACC仍可进行手术治疗。.

暂无摘要。

BACKGROUND: Primary tracheal acinic cell carcinoma (ACC) is an exceptionally rare malignancy, posing challenges in understanding its clinical behavior and optimal management. Surgical resection has traditionally been the primary treatment modality, but we present a compelling case of tracheal ACC managed with endotracheal intervention, challenging conventional approaches.
METHODS: A 53-year-old woman presented with shortness of breath, cough, and hemoptysis. Enhanced computed tomography revealed an obstructive tracheal lesion, leading to her referral for further assessment.
METHODS: Microscopic evaluation, immunohistochemistry, and clinical assessments confirmed primary tracheal ACC, an exceedingly rare condition with limited clinical insights.
METHODS: We utilized rigid bronchoscopy to perform endotracheal intervention, successfully resecting the tumor and restoring tracheal patency. Postoperatively, the patient received no radiotherapy or chemotherapy.
RESULTS: The patient achieved complete recovery, with 24-month follow-up examinations indicating no recurrence or metastatic disease. Only minimal scar tissue remained at the resection site.
CONCLUSIONS: This case demonstrates the potential of endotracheal intervention as a curative approach for primary tracheal ACC, minimizing invasiveness and preserving tracheal function. Collaborative research efforts and extensive case reporting are crucial for advancing our understanding of this rare malignancy and optimizing treatment strategies for improved patient outcomes.

OBJECTIVE: We performed a population-based cohort study to investigate the clinical characteristics and survival rates of primary malignant parotid tumors (MPT) in children and adolescents.
METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all pediatric and adolescent patients with MPT who were diagnosed between 2000 and 2018. Based on a number of parameters, survival curves were produced using Kaplane-Meier estimates. The log-rank test was used to compare survival curves. The influence of each component on overall survival (OS) was examined using a multivariate Cox proportional hazards model.
RESULTS: There were 352 identified pediatric and adolescent patients with MPT. At diagnosis, the age ranged from 1.0 to 19 years, with a median of 15 years. Mucoepidermoid carcinoma (MC) (46.5 %) was the most common histological subtype, followed by acinar cell carcinoma (ACC) (36.4 %) and others (17.1 %) such as adenoid cystic carcinoma and squamous cell carcinoma. All patients had overall survival rates of 98.8 %, 95.6 %, and 94.6 % at 1-year, 3-year and 5-year, respectively. The results of the Cox proportional hazard regression showed that tumor grade, SEER stage, radiotherapy, and treatment regimens were significant independent predictors of overall survival.
CONCLUSIONS: In pediatric and adolescent MPT, tumor grade, SEER stage, adjuvant radiation, and treatment regimens were found to be important independent predictors of survival. More research is required to validate the role of adjuvant radiation.

BACKGROUND: Primary synovial sarcoma of the prostate is an extremely rare mesenchymal malignant soft tissue tumor with unique morphological features. Synovial sarcoma often occurs in the pararticular tissues of limbs in young people, but rarely occurs in prostate. Because it is very rare, it is easily misdiagnosed as benign prostatic hyperplasia or prostate cancer clinically. A case of synchronous acinar adenocarcinoma of the prostate has not been reported. In this article, we report a unique case of primary prostatic synovial sarcoma with acinar adenocarcinoma.
METHODS: A 58-year-old male patient was found to have a prostate mass during physical examination. Prostate ultrasound examination showed an increase in prostate volume of 5.2 × 3.3 × 3.3 cm, mixed echo mass can be seen on the left side of the prostate, with a size of approximately 4.9 × 4.3 cm, left seminal vesicle compressed.
METHODS: Prostatic synovial sarcoma (biphasic type) combined with prostatic acinar adenocarcinoma (Gleason 3 + 3).
METHODS: The patient received radical prostatectomy, followed by adjuvant chemotherapy and radiotherapy.
RESULTS: After 2 months of follow-up, at the time of writing this article, the patient received a comprehensive treatment plan of adjuvant chemotherapy and radiotherapy for 2 months, and no recurrence or metastasis was found.
CONCLUSIONS: Primary prostatic synovial sarcoma (biphasic type) combined with prostatic acinar adenocarcinoma is a very unique and rare case, and effective treatment guidelines are not yet clear, posing new challenges to clinical treatment. Making full use of pathological and imaging examinations, early diagnosis and radical surgery combined with multidisciplinary treatment seem to be still a positive method.

Objective: To investigate the expression differences of LLGL2 between prostatic ductal adenocarcinoma (PDA) and prostatic acinar adenocarcinoma, and its potential clinical significance. Methods: Eighteen patients diagnosed of PDA or prostatic acinar adenocarcinoma with PDA component by histopathology during January 2015 and December 2019 in the Beijing Hospital, China were retrospectively studied. The transcriptome analysis was conducted using the tissue of PDA and prostatic acinar adenocarcinoma. Differentially expressed genes and the differences in expression profiles were identified. Further, differentially expressed proteins were verified by immunohistochemistry. Results: The tissue from 8 of the 18 patients were used for transcriptome analysis, the results of which were compared with data from public databases. 129 differentially expressed genes were identified. 45 of them were upregulated while 84 were downregulated. The results of gene enrichment analysis and gene oncology (GO) analysis revealed that the differentially expressed genes were mostly enriched in the hypertrophic cardiomyopathy and interleukin-17 related pathways. GPAT2, LLGL2, MAMDC4, PCSK9 and SMIM6 were differentially expressed between PDA and prostatic acinar adenocarcinoma. Moreover, LLGL2 was more likely expressed in the cytoplasm (P=0.04) than the nucleus (P<0.01) in PDA, compared with prostatic acinar adenocarcinoma. Conclusions: The gene expression profiling indicates that PDA are very similar to prostatic acinar adenocarcinoma. Among the differentially expressed proteins screened and verified in this study, the expression of GPAT2, LLGL2, MAMDC4 and PCSK9 is increased in PDA, while that of SMIM6 is reduced in PDA. The expression of LLGL2 shows significantly different patterns between PDA and prostatic acinar carcinoma, and thus may help differentiate PDA from prostatic acinar adenocarcinoma in clinical practice.
目的： 探讨前列腺导管腺癌（PDA）及腺泡腺癌中的差异表达蛋白及其潜在临床意义。 方法： 回顾北京医院2015年1月至2019年12月诊断前列腺癌且病理诊断为PDA或有PDA成分的18例患者的临床和病理信息。对PDA和腺泡腺癌组织进行转录组分析，并对比二者表达谱差异。对表达具有显著差异的蛋白进行免疫组织化学验证，并分析其表达模式差异。 结果： 18例PDA患者中8例进行转录组分析，表达量与公共数据库进行比较，通过差异基因分析，一共确定了129个表达差异基因，其中45个表达上调，84个表达下调。富集分析结果显示差异基因主要富集在与心血管相关（肥厚型心肌病）和白介素17相关的两条通路。表达谱的差异分析发现GPAT2、LLGL2、MAMDC4、PCSK9及SMIM6具有表达差异。进一步免疫组织化学分析显示，与腺泡腺癌相比，PDA的LLGL2细胞质染色强阳性表达较多（P=0.04），细胞核染色呈阴性（P<0.01）。 结论： 基因表达谱的结果表明PDA与腺泡腺癌非常相似。在筛选并验证的差异蛋白中，GPAT2、LLGL2、MAMDC4、PCSK9在PDA中表达增高，SMIM6在PDA中表达降低，其中LLGL2的表达在PDA与腺泡腺癌间存在表达部位的显著差异，可能成为一种潜在的标志物，在PDA与腺泡腺癌的鉴别诊断中得以应用。.