Acinar cell carcinoma: a rare pancreatic malignancy

Misunderstood Gastric Perforation of a Pancreatic Acinar Cell Carcinoma: A Wolf in Sheep’s Clothing

A 70-year-old man was admitted to the Emergency Department (ED) for marked asthenia and severe anemia. In addition, a high level of lipase was found. During hospitalization, a locally advanced gastric cancer was diagnosed, with endoscopic evidence of a large polyploid formation originating under the cardias that occupied most of the gastric lumen. A total body CT scan was performed before surgery; the tumor affected the posterior gastric wall, with tenacious infiltration of the pancreatic body. Therefore, we performed a total gastrectomy with esophageal jejunum anastomosis and reconstruction of intestinal continuity according to Roux, distal spleno-pancreatectomy, and cholecystectomy. At histology, a pancreatic acinar cell carcinoma (PACC) with full thickness infiltration of the gastric wall was diagnosed. Acinar cell carcinomas are highly aggressive neoplasms, and surgical resection, when feasible, is the treatment of choice regardless of size, also because the role of neoadjuvant or adjuvant chemo- or radiotherapy remains uncodified.

4H12, a Murine Monoclonal Antibody Directed against Myosin Heavy Chain-9 Expressed on Acinar Cell Carcinoma of Pancreas with Potential Therapeutic Application

Background:

PACC is a rare type of pancreatic exocrine neoplasm that is frequently diagnosed at late stages with a high rate of metastasis. Identification of new biomarkers for PACC can improve our knowledge of its biology, early detection, or targeted therapy. In this study, hybridoma technology was used to generate mAbs against Faraz-ICR, a pancreatic acinar cell carcinoma cell line.

Methods:

Cell ELISA and flow cytometry were used for screening, and the 4H12 hybridoma clone was selected for further analysis. The 4H12 mAb was specific for MYH9 as determined by Immunoprecipitation, Western blot, and mass spectrometry.

Results:

This antibody reacted variably with other cancer cells, in comparison to Faraz-ICR cell. Besides, by immunohistochemical staining, the acinar cell tumor, which was the source of Faraz-ICR, showed high MYH9 expression. Among 21 PDAC cases, nine (42.8%) expressed MYH9 with low intensity, while 10 (47.8%) and 2 (9.5%) cases expressed MYH9 with moderate to strong intensities, respectively. The 4H12 mAb inhibited the proliferation of Faraz-ICR cells in a dose-dependent manner from 0.75 to 12.5 μg/ml concentrations (p < 0.0001 and p < 0.002). IC₅₀ values were achieved at 12.09 ± 4.19 µg/ml and 7.74 ± 4.28 µg/ml after 24- and 48-h treatment, respectively.

Conclusion:

Our data suggest that the 4H12 mAb can serve as a tool for investigating the role of MYH9 pancreatic cancer biology and prognosis.

Pancreatic acinar cell carcinoma--literature review and case report of a 56-year-old man presenting with abdominal pain

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 acinar cell carcinoma presenting with panniculitis, successfully treated with FOLFIRINOX: A case report

Pancreatic acinar cell carcinoma (PACC) is a rare tumor of the exocrine pancreas, representing only 1% of all pancreatic malignancies. A 50-year-old man presented with edema of the thumb joints bilaterally, followed by an appearance of masses in the bilateral lower extremities and fever (38°C). The masses were diagnosed as panniculitis by skin biopsy, and multiple intraperitoneal masses were incidentally detected on pelvic magnetic resonance imaging performed to investigate the leg abnormalities. The patient was referred to the Kyushu University Hospital for further investigation, and fluorodeoxyglucose-positron emission tomography/computed tomography (CT) revealed high-uptake tumors in the pancreatic tail, in the periphery of the liver, and in the pelvis. Laboratory examinations revealed high serum concentrations of pancreatic exocrine enzymes, such as lipase, trypsin, elastase 1 and pancreatic phospholipase A2. Histological examination of a bioptic specimen obtained from a hepatic lesion revealed proliferation of atypical cells arranged in a tubular or glandular pattern. Immunohistochemical staining revealed that the atypical cells were positive for cytokeratin (CK)7, CK19 and lipase, but negative for CK20 and thyroid transcription factor-1, leading to a final diagnosis of acinar cell carcinoma of the pancreatic tail (T4bN0M1, stage IV according to the 7th edition of the TNM Classification of Malignant Tumors). Combined chemotherapy with oxaliplatin, irinotecan and fluorouracil (FOLFIRINOX) was administered and fever was soon alleviated. The serum levels of lipase also declined and panniculitis completely resolved. As of the start of the 8th course of chemotherapy, the levels of the pancreatic exocrine enzymes were within normal ranges and CT revealed partial response. Therefore, the severe lipase hypersecretion syndrome was well controlled by the FOLFIRINOX regimen and shrinkage of the mass was also achieved. Thus, the FOLFIRINOX regimen may represent an effective treatment option for advanced PACC.

Systematic Review and Case Series Report of Acinar Cell Carcinoma of the Pancreas

BACKGROUND

Acinar cell carcinoma of the pancreas is a rare malignancy representing less than 1% of all pancreatic malignancies.

METHODS

We report on a case series of 21 patients with acinar cell carcinoma of the pancreas treated at a high-volume quaternary center. A systematic review of the medical literature was performed that described typical therapeutic management approaches for acinar cell carcinoma of the pancreas and reported on disease control and survival rates. Data for the case series were obtained from a prospective database.

RESULTS

In our systematic review of 6 articles, study patients had a median age of 61 years, 66% were male, 52% had stage I/II disease, and 55% of lesions were located in the pancreatic head. The rates of median survival were approximately 47 months after resection with adjuvant therapy, 38 months for nonmetastatic, locally unresectable disease, and 17 months for metastatic disease treated with chemotherapy. Combination fluoropyrimidine-based chemotherapy regimens had better rates of disease control than other therapies. Our case series included 21 study patients, 14 of whom required resection and 7 who had metastatic disease. The rates of median survival were 40.2 ± 31.9 months in those who underwent surgery and were treated with adjuvant therapy and 13.8 ± 11.3 months for patients with metastatic disease.

CONCLUSIONS

Multidisciplinary treatment for acinar cell carcinoma of the pancreas should be considered due to the rarity of the disease and its lack of high-level therapeutic data. Progress in the molecular analysis of this tumor may improve outcomes through the use of personalized therapy based on underlying tumor mutations.

Clinical features and CT/MRI findings of pancreatic acinar cell carcinoma

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.