Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic tumor type, and ruptured pancreatic tumors are rarer. Computed tomography (CT) in a 48-year-old man incidentally revealed a raptured pancreatic tail tumor. The patient was treated conservatively because he was asymptomatic, and his general condition was stable. After a detailed examination, the pancreatic tumor was diagnosed as raptured PACC. Considering the potential infiltration of tumor cells into the hematoma within the omental sac, our decision is to initiate chemotherapy as the primary course of action. A liquid biopsy was performed, and comprehensive genomic profiling of circulating tumor DNA showed a tumor BRCA2 mutation. Chemotherapy with modified FOLFIRINOX (mFFX) was selected as the first treatment. After seven courses of mFFX, the primary tumor diminished remarkably. At this time, the radical resection was performed via distal pancreatectomy with simultaneous resection of the gastric wall and colon, which had adhered strongly to the tumor. Histopathological examination revealed that the tumor had shrunk to less than 5% of its original size due to chemotherapy (Grade 3 of Evans Classification). Devising treatment strategies for ruptured pancreatic malignant tumors is challenging due to the worsening general condition caused by severe abdominal symptoms and intra-abdominal bleeding. In this context, this case-report documents a rare instance of raptured PACC with a tumor BRCA2 mutation that underwent radical resection following mFFX treatment.

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.

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.

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.

We present a case of acinar cell carcinoma of the pancreas (ACC) with metastasis to the liver in a patient who presented with complaints abdominal pain. The presentation, diagnosis, and management of a 56-year-old man with ACC are discussed here. Imaging with computerized tomography (CT) in particular is crucial in the diagnosis, which can identify the primary lesion as well as metastases. ACC should be considered in the differential as a source of abdominal, epigastric, or back pain with imaging that is suggestive of the diagnosis as prompt recognition and initiation of treatment is paramount in the overall prognosis.

Pancreatic carcinomas with acinar differentiation are rare, accounting for 1%-2% of adult pancreatic tumors; they include pancreatic acinar cell carcinoma (PACC), pancreatoblastoma, and carcinomas of mixed differentiation. Patients with PACC have a prognosis better than pancreatic ductal adenocarcinomas but worse than pancreatic neuroendocrine tumors. Reports of overall survival range from 18 to 47 mo. A literature review on PACCs included comprehensive genomic profiling and whole exome sequencing on a series of more than 70 patients as well as other diagnostic studies including immunohistochemistry. Surgical resection of PACC is the preferred treatment for localized and resectable tumors. The efficacy of adjuvant treatment is unclear. Metastatic PACCs are generally not curable and treated with systemic chemotherapy. They are moderately responsive to chemotherapy with different regimens showing various degrees of response in case reports/series. Most of these regimens were developed to treat patients with pancreatic ductal adenocarcinomas or colorectal adenocarcinomas. Review of PACC\'s molecular profiling showed a number of gene alterations such as: SMAD4, BRAF, BRCA2, TP53, RB1, MEN1, JAK-1, BRCA-1, BRCA-2, and DNA mismatch repair abnormalities. PACCs had multiple somatic mutations with some targetable with available drugs. Therefore, molecular profiling of PACC should be an option for patients with refractory PACC.

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic tumor, with an estimated frequency of less than 1% of pancreatic malignancies. There are no prospective studies to guide diagnostic or therapeutic algorithms. We report the case of a 36 year-old woman, diagnosed of a pancreatic tumor with liver and peritoneal metastases that was initially managed as a neuroendocrine tumor with temozolomide and capecitabine. After two cycles a severely painful arthritis developed in her left ankle with panniculitis and extensive fat necrosis, and CT scan demonstrated progressive disease. Pathology of the primary was reassessed establishing the diagnosis of PACC. The patient started treatment with FOLFIRINOX regimen, achieving clinical benefit and disease stabilization. We also briefly reviewed the literature on this rare subtype of pancreatic tumor.