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.

A 73-year-old Japanese man with a history of distal biliary cancer treated by pancreatoduodenectomy developed pancreatic acinar cell carcinoma (PACC) treated by remnant pancreatectomy and adjuvant chemotherapy. Thirteen months after surgery, multiple liver metastases developed and FOLFOX chemotherapy was initiated. Based on the PACC diagnosis and a positive family history for breast and ovarian cancer genetic testing was performed which revealed a pathogenic germline BRCA2 variant (c.8629G > T, p.Glu2877Ter). Olaparib therapy was initiated and the metastases responded well (partial response). PACC is a BRCA2-associated cancer which may respond well to PARP inhibitors.

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。.

Pancreatic acinar cell carcinomas are rare malignant neoplasms. High-quality evidence about the best treatment strategy is lacking. We present the case of a 52-year-old male with a BRAFV600E -mutated PACC who experienced a complete remission after chemotherapy with BRAF-/MEK-inhibitors.
The patient presented with upper abdomen pain, night sweat, and weight loss. CT scan showed a pancreatic tumor extending from the pancreas head to body. Histological workup identified an acinar cell carcinoma. As the tumor was inoperable, chemotherapy with FOFIRNIOX was initiated and initially showed a slight regression of disease. The regimen had to be discontinued due to severe side effects. Molecular analysis identified a BRAFV600E mutation, so the patient was started on BRAF- and MEK-inhibitors (dabrafenib/trametinib). After 16 months, CT scans showed a near complete remission with a markedly improved overall health.
Studies suggest that up to one-fourth of PACCs carry a BRAF mutation and might therefore be susceptible to a BRAF-/MEK-inhibitor therapy. This offers a new therapeutic pathway to treat this rare but malignant neoplasm.

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.

A 31-year-old man with a big epigastric mass from pancreas body was completely removed by distal pancreatectomy and segmental gastrectomy. Two years after oral administration of S-1 for 4 courses, peritoneal dissemination on the right subdiaphragmatic space was detected. Laparotomy revealed white colored round nodules were found scattered on the peritoneal surface, and the peritoneal cancer index(PCI)was 18. To achieve complete resection of peritoneal nodules, peritonectomy was performed. After complete removal of macroscopic peritoneal metastasis(PM), intraoperative hyperthermic intraoperative peritoneal chemotherapy using 1 gr of gemcitabine and 60 mg of docetaxel was performed for 40 min with thermal dose of 41.5 min. Postoperative course was uneventful. Drug sensitivity test(HDRA method)showed that gemcitabine that gemcitabine showed the highest inhibition rate. The patient was treated with systemic gemcitabine chemotherapy. He is still alive without recurrence 18 months after peritonectomy plus intraoperative HIPEC. Pathological examination showed pancreatic acinar cell carcinoma(PACC)demonstrating positive for chymotrypsin. In conclusion, we present a PACC-case with PM successfully treated by a comprehensive treatment. Intraoperative HIPEC using gemcitabine may be effective for PACC patients with PM in treating residual micrometastasis after peritonectomy.

暂无摘要。

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.

Secretory carcinoma is a relatively recently discovered low-grade salivary gland carcinoma with morphological similarities to its breast counterpart. The histopathological features of this entity are well established; however, the cytomorphological features are not well evaluated, leading to diagnostic challenges and pitfalls. We report a case of secretory carcinoma (SC) of the parotid gland, which was misdiagnosed as acinic cell carcinoma (ACC) on fine-needle aspiration cytology, to describe the cytological features.

Lipase hypersecretion syndrome (LHS) is a rare paraneoplastic syndrome, associated with acinar cell carcinoma of the pancreas (ACCP) in 10% to 15% of patients. Clinically, LHS manifests itself with the appearance of subcutaneous fibrocystic nodules, associated with trophic changes in the overlying skin, such as ulcers or fistulas that are difficult to manage, mainly affecting the lower extremities. Additionally, lipolysis near the joints and in the intraosseous adipose tissue can cause bilateral arthralgias, especially of the knees and ankles. We report a 57-year-old man, with a history of insulin resistance and allergic rhinitis, who presented in June 2019 with multiple subcutaneous nodules in the lower extremities, predominantly in both ankles, associated with arthralgia in that region. Additionally, a CT scan of the abdomen revealed a significant abdominal mass, measuring approximately 17 cm and in contact with the body and tail of the pancreas, pathologically compatible with an ACCP. Treatment with capecitabine was started with a favorable progression. The patient currently presents a small left lateral retro malleolar fistula, which, given the analyzes, studies and reviewed literature is concluded to be a lesion in the context of LHS.