Paediatric pancreatic acinar cell carcinoma (PACC) presents a diagnostic challenge, often confused with pancreatoblastoma (PB) due to its rarity. It is crucial to differentiate between PB and PACC, given their distinct therapeutic strategies and prognoses. Histologically, the absence of squamoid nests and scarcity of tumor mesenchyme support PACC. Conversely, the identification of a BRAF alteration leans towards PACC. Here, we present the case of an 8-year-old girl with a well-defined mass in the pancreas. The tumor exhibited a SEC31A-BRAF fusion gene and amplification of 18p, showcasing unequivocal acinar differentiation and a minor degree of neuroendocrine differentiation. Additionally, the tumor displayed scant fibrous stroma, and an absence of squamoid nests, further supporting PACC. Notably, this is the first reported instance of a solid tumor featuring a SEC31A-BRAF gene fusion. The discovery of this novel fusion gene expands our understanding of BRAF fusion partner profiles, particularly in the context of paediatric PACC.

BACKGROUND: This is the first report of an ROS1-CENPW fusion gene in pancreatic malignancies.
METHODS: A 77-year-old woman with a pancreatic tumor and multiple liver metastases was admitted to our hospital. Genetic testing revealed the presence of the ROS1-CENPW fusion gene, a rare fusion gene that has not been previously reported in the field of pancreatic cancer. The patient received crizotinib plus AG (albumin paclitaxel plus gemcitabine) chemotherapy. After treatment, the patient\'s condition stabilized, and her prognosis was good.
CONCLUSIONS: The ROS1-CENPW gene treatment regimen used in this case is an excellent treatment option that provides new hope for patients with advanced pancreatic cancer and similar genetic mutations. To date, owing to the rarity of the ROS1-CENPW fusion gene, our team has encountered only a single case. Therefore, the efficacy of crizotinib plus AG chemotherapy in patients with pancreatic acinar cell carcinoma harboring the ROS1-CENPW fusion gene requires further validation.

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic malignancy with unique clinical, molecular, and morphologic features. The long-term survival of patients with PACC is substantially better than that of patients with ductal adenocarcinoma of the pancreas. Surgical resection is considered the first choice for treatment; however, there is no standard treatment option for patients with inoperable disease. The patient with metastatic PACC reported herein survived for more than 5 years with various treatments including chemotherapy, radiotherapy, antiangiogenic therapy and combined immunotherapy.

UNASSIGNED: Pancreatic acinar cell carcinoma (PACC) is rare, and its appropriate treatment remains unknown. We aim to explore the characteristics and optimal treatment of it.
UNASSIGNED: The data on clinicopathologic characteristics, molecular alteration, treatment, and survival of patients diagnosed with PACC at the Sun Yat-sen University Cancer Center from 2005 to 2020 were collected. The optimal treatment was explored by co-analyzing our results and published literatures.
UNASSIGNED: Twenty-two PACC patients were enrolled. Eight of 17 non-metastatic patients received adjuvant chemotherapy. The patients receiving fluoropyrimidine-based regimen (n = 3) had a better median disease-free survival (mDFS) than those with gemcitabine-based regimen (n = 5) (unreached vs 27 months). Eight metastatic patients received first-line chemotherapy. Four patients received second-line chemotherapy. The objective response rate (ORR) of the fluoropyrimidine-based regimen was 85.7% (6/7), much better than that of the gemcitabine-based regimen (0/5). One patient who had responded to the first-line FOLFIRINOX (5-fluorouracil + oxaliplatin + leucovorin + irinotecan) regimen received olaparib as maintenance treatment for 5 months with good tolerance. Thirty-one published literatures, with a total of 86 cases, were included in the co-analysis. The ORR of the first-line fluoropyrimidine-based regimen (n = 47) was higher than that of gemcitabine-based regimen (n = 39) (59.6% vs 15.3%, P < .001). Eight of 11 patients treated with the FOLFIRINOX regimen achieved partial response (PR).
UNASSIGNED: For patients with metastasis, a fluorouracil-based regimen such as FOLFIRINOX may be preferred, and maintenance treatment of poly ADP-ribose polymerase (PARP) inhibitors after effective platinum-containing treatment for breast cancer susceptibility gene (BRCA) mutation patients must be assessed.

BACKGROUND: Multiple primary malignant tumors are two or more malignancies in an individual without any relationship between the neoplasms. In recent years, an increasing number of cases have been reported. However, concomitant primary gastric and pancreatic cancer reported a relatively small incidence, involving no pancreatic acinar cell carcinoma reports. Here, we present the first case of concomitant pancreatic acinar cell carcinoma and gastric adenocarcinoma.
METHODS: A 69-year-old male presented to our department with a history of vomiting, epigastric pain, and weight loss. Imaging revealed space-occupying lesions in the stomach and the tail of the pancreas, respectively. The patient underwent laparoscopic radical gastrectomy and pancreatectomy simultaneously. The pathologies of surgical specimens were completely different: The resected gastric specimen was moderate to poorly differentiated adenocarcinoma, whereas the pancreatic tumor was consistent with acinar cell carcinoma. The patient was treated with six cycles of oxaliplatin and S-1 chemotherapy. As of March 2021, the patient was healthy without any recurrence or metastasis. After thoroughly reviewing the literature on simultaneous pancreatic and gastric cancers at home and abroad, we discussed the clinical characteristics of these rare synchronous double cancers. Most of the cases had undergone surgery and adjuvant chemotherapy, and all of the cases were pathologically confirmed by the postoperative specimen.
CONCLUSIONS: Synchronous pancreatic acinar cells and gastric adenocarcinoma can occur and should be considered when tumors are found in these organs.

A 48-year old woman was diagnosed with metastatic pancreatic acinar cell carcinoma (PACC) and with a marked elevation in alpha-fetoprotein (AFP), this being a recognized but uncommon feature of PACC. As she refused chemotherapy, the combined therapy of lenvatinib and sintilimab (lenvatinib 8 mg, orally, qd; and sintilimab 100 mg, intravenous glucose tolerance test, q21d) was given, which conferred significant tumor shrinkage and long progression-free survival (>21 months). This study is the first report and description of a PACC demonstrating favorable response to the combination therapy of an antiangiogenic agent and immunotherapy.

BACKGROUND: Pancreatic acinar cell carcinoma (PACC) is a rare malignancy that accounts for less than 1% of primary pancreatic neoplasms. Currently, the lack of large-scale clinical studies limits our understanding of PACC. The aim of this study was to investigate the clinical characteristics and prognosis of PACC.
METHODS: In a retrospective analysis, 52 patients with PACC and 355 patients with pancreatic ductal adenocarcinoma (PDAC) who underwent surgical interventions were evaluated. Clinical characteristics and treatment outcomes were compared between the two groups.
RESULTS: The mean age was lower for patients with PACC than for those with PDAC (mean: 50.8 ± 10.9 versus 59.4 ± 10.9 years; p < 0.001). Except for alpha-fetoprotein (AFP), tumour markers were also lower in the PACC group than the PDAC group. In regard to tumour characteristics, maximum diameters of the primary tumour [median (range): 5.0 cm (1.0-18.2 cm) versus 3.5 cm (0.6-15.0 cm); p < 0.001] and hepatic metastatic lesions [6.7 cm (1.5-12.6 cm) versus 1.2 cm (0.3-3.3 cm); p < 0.001] were larger in patients with PACC than patients with PDAC, but vascular invasion [23.1% (12/52) versus 35.5% (126/355); p = 0.044] and perineural invasion [7.7% (4/52) versus 56.1% (199/355); p < 0.001] were more common in patents with PDAC than in patients with PACC. For treatment, radical resection was performed in 57.7% of patients with PACC, which increased the 5-year survival rate to 31.8%. In regard to prognosis, the 5-year survival rate was 21.4% for PACC and 9.7% for PDAC (p < 0.0001).
CONCLUSIONS: PACC is more indolent than PDAC, which makes early diagnosis more difficult. Although the stage may be advanced at diagnosis, the overall survival (OS) of PACC is much better than that of PDAC, and the prognosis greatly improves after radical resection.

BACKGROUND: Pancreatic acinar cell carcinoma (PACC) is a rare tumor, accounting for about 1% of all pancreatic exocrine cancers. Consensus on the management of metastatic PACC remains unclear.
METHODS: Starting from April 2019, a patient first received chemotherapy with two cycles of gemcitabine and nab-paclitaxel and two cycles of SOX regimen. After progression of disease evaluated based on RECIST 1.1, toripalimab and SOX regimen was administered because of PD-L1-positive expression, high tumor mutation burden (TMB), and somatic FANCA deletion in the tumor. Both the primary and metastatic tumor mass shrank significantly after two courses. The patient exhibited sustained partial response for at least six courses with well-controlled toxic effects. Then the treatment had to be stopped for 2 months because of the coronavirus disease 2019 pandemic. Computed tomography scan in March 2020 showed disease progression. Time from initiating treatment to tumor progression on toripalimab and SOX regimen treatment took up to at least 8 months.
CONCLUSIONS: We present the first case report where a PD-L1 positive, high TMB, and FANCA-deleted pancreatic acinar cell carcinoma was treated using chemotherapy combined with immunotherapy, in which the patient exhibited satisfactory response and tolerance.

To retrospectively review the clinical features and computed tomography (CT) and magnetic resonance imaging (MRI) findings of PAAC so as to improve the accuracy of imaging diagnosis. Seventeen patients with pathologically proven PAAC were enrolled. Their clinical and imaging findings were retrospectively reviewed. The median age of the patients was 56 years (range, 7-74 years). The tumors were located in any part of the pancreas or exophyitc growth, with a median maximal diameter of 68 mm. Thirteen masses presented with ovoid shape. Nine masses had less clear boundaries. Eleven masses showed a variable degree of intratumoral hypodense or necrosis before contrast administration on CT images. Five masses showed hypointense on unenhanced T1 weighted images and hyperintense on T2 weighted images. After contrast administration, the most common enhancement pattern was slight enhancement on arterial phase and persistent enhancement on portal vein phase. Infiltration of tumor into duct and vessels was not common. Five and 2 patients developed hepatic metastasis and local lymphadenopathy, respectively. By the end of the last follow-up, 11 patients survived free of disease. PAAC should be included in the differential diagnosis when a bulky, ovoid, heterogeneous mass, with clear or less clear margins, in the pancreas or peripancreas, with slight and persistent enhancement after contrast administration on CT or MRI images is seen, particularly in elder men.