Locally advanced acinar cell carcinoma of the pancreas successfully treated by capecitabine and concurrent radiotherapy: report of two cases

Comprehensive review of pancreatic acinar cell carcinoma: epidemiology, diagnosis, molecular features and treatment

Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from pancreatic ductal adenocarcinoma. Pancreatic acinar cell carcinoma occurs more frequently in males and can occur in children. Serum lipase is elevated in 24-58% of patients with pancreatic acinar cell carcinoma. Pancreatic acinar cell carcinomas tend to be large at diagnosis (median tumour size: ~5 cm) and are frequently located in the pancreas head. Radiologically, pancreatic acinar cell carcinoma generally exhibits a solid appearance; however, necrosis, cystic changes and intratumoral haemorrhage can occur in larger lesions. Immunostaining is essential for the definitive diagnosis of pancreatic acinar cell carcinoma. Compared with pancreatic ductal adenocarcinoma, pancreatic acinar cell carcinoma has a more favourable prognosis. Although radical surgery is recommended for patients with pancreatic acinar cell carcinoma who do not have distant metastases, the recurrence rate is high. The effectiveness of adjuvant therapy for pancreatic acinar cell carcinoma is unclear. The response to FOLFIRINOX is generally favourable, and some patients achieve a complete response. Pancreatic acinar cell carcinoma has a different genomic profile compared with pancreatic ductal adenocarcinoma. Although genomic analyses have shown that pancreatic acinar cell carcinoma rarely has KRAS, TP53 and CDKN2A mutations, it has a higher prevalence of homologous recombination-related genes, including BRCA1/2 and ATM, than pancreatic ductal adenocarcinoma, suggesting high sensitivity to platinum-containing regimens and PARP inhibitors. Targeted therapies for genomic alternations are beneficial. Therefore, genetic testing is important for patients with pancreatic acinar cell carcinoma to choose the optimal therapeutic strategy.

Survival Outcomes of Acinar Cell Pancreatic Cancer: A National Cancer Database Analysis

OBJECTIVES

Acinar cell pancreatic carcinomas (ACPCs) are rare neoplasms accounting for 1% to 2% of pancreatic tumors in adults. The objective of this study is to evaluate the benefit of chemotherapy in the adjuvant setting in resected ACPC and in the palliative setting for metastatic ACPC.

METHODS

Data were obtained from all US hospitals that contributed to the National Cancer Database between 2004 and 2014. Cases were identified using the histology code 8550.

RESULTS

A total of 593 patients with ACPC were identified. The mean age was 64.4 years (range, 18-90 years), with a male preponderance (72.8%, n = 432). Localized stage disease comprised 52.3% (n = 310) of patients. Among localized ACPC patients, 88.0% (n = 191) underwent surgery and 50.6% (n = 91) received adjuvant chemotherapy. The 5-year overall survival in those who received adjuvant treatment was slightly higher than those who did not receive adjuvant treatment (46.7% vs 44.8%, P = 0.3271). Among advanced-stage ACPC patients, 67.6% received chemotherapy, which translated into improved 5-year overall survival compared with no chemotherapy (8.1% vs 0%, P < 0.0001).

CONCLUSIONS

Chemotherapy in the palliative setting for advanced-stage ACPC patients was associated with improved survival. Adjuvant therapy did not translate into significant survival benefit.

The contemporary trend in worsening prognosis of pancreatic acinar cell carcinoma: A population-based study

BACKGROUND

Primary acinar cell carcinoma (ACC) is a rare exocrine tumor of the pancreas with unclear clinical characteristics. Our goal was to determine the incidence and update the clinical characteristics and outcomes of ACC.

METHODS

Through the Surveillance, Epidemiology, and End Results (SEER) database, we identified 252 patients with the latest diagnosis of ACC (2004-2016). The age-adjusted incidence (AAI) was calculated using the SEER*Stat Software version 8.3.6. The Kaplan-Meier method was used to draw survival curves and differences among them were compared by the log-rank test. Cox proportional hazards models were used to evaluate factors that had independent predictive effects on the overall survival.

RESULTS

The AAI of pancreatic ACC was on the rise with the mean age at diagnosis of 63.79±14.79 years. Most patients (15.9%) had poorer differentiated tumors. The patients presented with distant stage were 54.4% compared with 53.1% between 1988 and 2003. The 1-, 2-, and 5-years survival rates for pancreatic ACC patients were 53.5%, 34.6%,17.5%, respectively (compared with 78.5%, 67.0%, and 42.8%, between 1988 and 2003). The multivariate COX analysis showed that the patient's age, surgery, chemotherapy, and summary stage, but not marital status were independent prognosis factors for ACC.

CONCLUSIONS

Pancreatic ACC is a highly malignant tumor with an increasing incidence in recent years. The rate of distant metastasis is increasing and the survival rate is worse than in the past, suggesting that it may require more aggressive treatment and follow-up. Surgery, radiotherapy, and chemotherapy are all effective treatments, but prospective studies are still needed to verify them.

Patients With Acinar Cell Carcinoma of the Pancreas After 2005: A Large Population Study

OBJECTIVES

Acinar cell carcinoma of the pancreas is a rare tumor with limited data. We aim to evaluate the characteristics, treatments, and outcomes of pancreatic acinar cell carcinoma after 2005.

METHODS

We retrospectively reviewed patients with pancreatic acinar cell carcinoma treated in Peking University Cancer Hospital and Institute (2005-2018) and identified cases from Surveillance, Epidemiology, and End Results database (2005-2015).

RESULTS

A total of 306 cases in our institute (n = 11) and Surveillance, Epidemiology, and End Results database (n = 295) were identified. The median age was 67 years, and 73.5% were male. The 5-year survival was 36.8% for all patients (median, 27 months). About 37% underwent surgical resection. The 5-year survival was 65.6% for resected patients as compared with 16.9% for unresected ones (P < 0.0001). Among locoregional and metastatic diseases, surgery significantly prolonged survival as well (P = 0.0003). Stage IV patients who received chemotherapy had a better survival than those without it (median, 16 vs 3 months; P = 0.0019). Aging, stage IV, and no surgery were independent predictors of poor overall survival.

CONCLUSIONS

For pancreatic acinar cell carcinoma, surgery is a potentially curative treatment contributing to long-term survival and suggested even in advanced diseases. Chemotherapy improved survival for metastatic patients.

Successful chemotherapy with modified FOLFIRINOX for pancreatic acinar cell carcinoma

Abdominal ultrasonography revealed a pancreatic mass in a 67-year-old man with diabetes mellitus. Endoscopic ultrasound-guided fine needle aspiration led to the histological diagnosis of acinar cell carcinoma. The clinical stage was determined to be IVb based on findings of multiple metastatic lesions in the liver and lymph nodes, as well as splenic vein infiltration. Because the patient was not a surgical candidate, he underwent chemotherapy with modified FOLFIRINOX. In the absence of any severe adverse events, 12 courses of chemotherapy were delivered, resulting in marked shrinkage of both the primary and metastatic lesions. The outcome was judged to be a partial response, which was maintained even 9 months from the introduction of the chemotherapy. The results of this case suggest that modified FOLFIRINOX is safe and effective in the treatment of pancreatic acinar cell carcinoma.

Pancreatic acinar cell carcinoma with extensive tumor embolism at the trunk of portal vein and pancreatic intraductal infiltration

A 59-year-old man was admitted to the hospital with acute pancreatitis. The cause was suggested to be a pancreatic tumor based on computed tomography (CT). The pancreatic tumor was 45 mm with an extensive tumor embolism at the trunk of the portal vein and intraductal infiltration of the main pancreatic duct (MPD). The pancreatic tumor was diagnosed as acinar cell carcinoma (ACC) by endoscopic ultrasound guided fine needle aspiration. Therefore, the cause of acute pancreatitis was diagnosed to be intraductal infiltration of ACC in the MPD. Chemotherapy was initially performed because it was difficult to perform surgery due to extensive tumor embolism at the trunk of the portal vein. Degeneration and reduction of ACC and tumor embolism of the portal vein was noted on CT after chemotherapy, and extended distal pancreatectomy with portal vein reconstruction was performed. There has been no relapse for 5 years postoperative follow-up. This is an interesting and rare case because ACC with intraductal infiltration of MPD is low in frequency; most ACCs are asymptomatic when they are found, and many cases tend to have poor prognosis in spite of surgical cases.

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.

Acinar Cell Carcinoma of the Pancreas Successfully Controlled by IRIS: A Case Report and Literature Review

Acinar cell carcinoma (ACC) of the pancreas is a rare pancreatic tumor with poor prognosis. We present the first case of ACC of the pancreas successfully controlled by S-1 combined with a colorectal regimen. A 49-year-old Japanese female was referred to our clinic for right upper quadrant pain. Imaging studies demonstrated 2 solid tumors under the pancreas, and pancreatoduodenectomy with tumor resection was performed. Based on pathologic examination, the diagnosis of ACC of the pancreas was made according to the World Health Organization criteria. Eleven months after surgery, lymph node recurrence with elevations in serum concentrations of carbohydrate antigens (CA) 19–9 and CA125 were recognized. Treatments with carboplatin combined with paclitaxel, docetaxel, and gemcitabine, respectively, were attempted; however, there were no significant responses to these regimens. After starting S–1/irinotecan combination chemotherapy (IRIS), the concentrations of the tumor markers declined, accompanied by a reduction in tumor size. Because S-1 is an oral anticancer agent used on an outpatient basis with a low incidence of side effects, we believe that S–1-based chemotherapy is a strong candidate for the first-line treatment of recurrent or unresectable ACC.

Long-term survival following pancreatectomy and s-1 chemotherapy for pancreatic acinar cell carcinoma with peritoneal dissemination: a case report and literature review

Current case is the third report of S-1 chemotherapy against acinar cell carcinoma (ACC) of pancreas, and our patient has achieved the longest reported recurrence-free survival, longer than 6 years, despite the presence of disseminated nodules at laparotomy.A 77-year-old man presented with abdominal discomfort. Computed tomography showed a low-density tumor in the pancreas tail and the patient was referred for surgery. A 3-cm sized pancreatic tumor, with localized disseminated nodules, was detected on laparotomy. Distal pancreatectomy with concomitant resection of disseminated nodules was performed, and histopathological examination revealed an ACC. Oral S-1 chemotherapy was administered postsurgery, and the patient showed no sign of recurrence during 73 months of follow-up. This is the first report of long-term survivor of pancreatic ACC with peritoneal dissemination, following pancreatectomy and S-1 chemotherapy.Current case suggests a beneficial effect of S-1 chemotherapy in cases of ACC.

[A case of acinar cell carcinoma of pancreas, manifested by subcutaneous nodule as initial clinical symptom]

Pancreas acinar cell carcinoma (ACC) accounts for only 1-2% of pancreatic exocrine malignant tumor. The symptoms of patients with ACC are usually non-specific, for example the anorexia and weight loss. Patients may develop Schmid's triad including subcutaneous fat necrosis, polyarthritis, and eosinophilia. We reported a case of ACC which was manifested by subcutaneous nodule as initial clinical symptom. To our knowledge, this is the first reported case of ACC presenting as subcutaneous fat necrosis in Korea.

Acinar cell carcinoma of the pancreas: a rare tumor with a particular clinical and paraclinical presentation

Acinar cell carcinoma (ACC) of the pancreas is a rare tumor with an extremely low incidence rate. While the number of reported patients with ACC is relatively small, a long-term survival rate has been noted in patients with neuroendocrine differentiation. A 39-year-old woman visited our emergency department for upper gastrointestinal bleeding. Endoscopy indicated extrinsic compression of the posterior body of the stomach, together with a large, 10-cm, central ulcer covered with necrotic tissue. Abdominal computed tomography (CT) indicated a lesion that involved the whole of the pancreas, with a fistula in the stomach, which was suspected of being a degenerative intraductal papillary mucinous tumor of the pancreas. Magnetic resonance imaging (MRI) of the pancreas was performed, and the results further strengthened our suspicions by demonstrating the presence of cystic lesions and tumor buds. A total duodenopancreatectomy, including total splenectomy and gastrectomy, was performed, along with two independent Roux-en-Y anastomoses (one esojejunal and one hepaticojejunal). The tumor also had a wide opening in the stomach. The patient's postoperative course was marked by partial thrombosis of the portal vein, which was treated medically. Histopathological examination provided evidence of pancreatic ACC. The diagnosis of ACC should be considered in the presence of cutaneous lesions, which were absent in the case of our patient, and colonoscopy is also highly desirable because of the various forms associated with familial adenomatous polyposis. The prognosis, which includes a 5-year survival rate of 45%, in the population with an R0 resection is better than that for ductular adenocarcinoma, thus prompting the more aggressive management of this type of tumor.

An effective personalized approach to a rare tumor: prolonged survival in metastatic pancreatic acinar cell carcinoma based on genetic analysis and cell line development

Acinar cell carcinoma of the pancreas is an uncommon malignancy, accounting for less than 1% of all pancreatic neoplasms. Because of its rarity, only a few retrospective studies are available to help guide management. We report the case of a patient with metastatic ACC who achieved prolonged survival as a result of personalized treatment designed in part on the basis of molecular and in-vitro data collected on analysis of the tumor and a cell line developed from the liver metastasis. To our knowledge, this represents the first human cell line of ACC. The molecular findings on this case and this patient's cell line may be of use in the management of future cases of this rare tumor and allow the identification of potential novel targets for the effective treatment of this disease.

A case of pancreatic acinar cell carcinoma metastatic to skin

We report a rare case of pancreatic acinar cell carcinoma with widespread metastases in a 68-year-old woman who presented with subcutaneous nodules as the initial symptom. Computed tomography showed a pancreatic mass with hepatic tumors and enlarged lymph nodes besides ring-enhanced subcutaneous nodules. Magnetic resonance diffusionweighted imaging detected the presence of lesions in other organs. Histological analysis of a colonic polypoid lesion revealed carcinoma with endocrine and acinar differentiation compatible with pancreatic origin. Regrettably, she died of a cerebral infarction without any treatment, and autopsy findings confirmed our diagnosis.

Aggressive approach to acinar cell carcinoma of the pancreas: a single-institution experience and a literature review

PURPOSE

Acinar cell carcinomas (ACCs) are a rare pancreatic tumor group with no standardized treatment. The aim of the study is to analyze the clinical and pathologic characteristics of our series and to review the current literature.

METHODS

Retrospective review of prospectively collected data from 1990 to 2007 included patients who underwent pancreatic resection for histologically proven ACCs. All specimens of ACC were rereviewed by an expert pathologist. Follow-up was updated to October 2009. A literature search was performed by Pubmed and COCHRANE library.

RESULTS

Among 1,210 patients who underwent pancreatic resection, we identified nine ACCs. R0 resection was possible for all but one R1. We had no major complications and no mortality. All nine cases were diagnosed as pure ACCs. Five patients received adjuvant chemotherapy. Median overall survival was 31 months, while median disease-free survival was 18 months. All patients developed liver metastases, requiring modification of chemotherapeutic schema, radiofrequency ablation techniques, or reiterate surgery. Currently, only one patient is alive without evidence of disease 85 months after pancreatic resection. One patient is alive 52 months after operation, with evidence of recurrent disease.

CONCLUSIONS

ACC represents a rare solid tumor of the pancreas. Prognosis is dismal, although, compared to the more common ductal adenocarcinoma, survival appears to be longer. Patients with metastatic disease might benefit from aggressive multimodality treatments.

Fluorescence in situ hybridization to visualize genetic abnormalities in interphase cells of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas

OBJECTIVE

To use fluorescence in situ hybridization (FISH) to visualize genetic abnormalities in interphase cell nuclei (interphase FISH) of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas.

PATIENTS AND METHODS

Between April 4, 2007, and December 4, 2008, interphase FISH was used to study paraffin-embedded preparations of tissue obtained from 18 patients listed in the Mayo Clinic Biospecimen Resource for Pancreas Research with a confirmed diagnosis of acinar cell carcinoma, ductal adenocarcinoma, islet cell carcinoma, or pancreas without evidence of neoplasia. FISH probes were used for chromosome loci of APC (see glossary at end of article for expansion of all gene symbols), BRCA2, CTNNB1, EGFR, ERBB2, CDKN2A, TP53, TYMP, and TYMS. These FISH probes were used with control probes to distinguish among various kinds of chromosome abnormalities of number and structure.

RESULTS

FISH abnormalities were observed in 12 (80%) of 15 patients with pancreatic cancer: 5 of 5 patients with acinar cell carcinoma, 5 of 5 patients with ductal adenocarcinoma, and 2 (40%) of 5 patients with islet cell carcinoma. All 3 specimens of pancreatic tissue without neoplasia had normal FISH results. Gains of CTNNB1 due to trisomy 3 occurred in each tumor with acinar cell carcinoma but in none of the other tumors in this study. FISH abnormalities of all other cancer genes studied were observed in all forms of pancreatic tumors in this investigation.

CONCLUSION

FISH abnormalities of CTNNB1 due to trisomy 3 were observed only in acinar cell carcinoma. FISH abnormalities of genes implicated in familial cancer, tumor progression, and the 5-fluorouracil pathway were common but were not associated with specific types of pancreatic cancer.

Fluorescence in situ hybridization to visualize genetic abnormalities in interphase cells of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas

OBJECTIVE

To use fluorescence in situ hybridization (FISH) to visualize genetic abnormalities in interphase cell nuclei (interphase FISH) of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas.

PATIENTS AND METHODS

Between April 4, 2007, and December 4, 2008, interphase FISH was used to study paraffin-embedded preparations of tissue obtained from 18 patients listed in the Mayo Clinic Biospecimen Resource for Pancreas Research with a confirmed diagnosis of acinar cell carcinoma, ductal adenocarcinoma, islet cell carcinoma, or pancreas without evidence of neoplasia. FISH probes were used for chromosome loci of APC (see glossary at end of article for expansion of all gene symbols), BRCA2, CTNNB1, EGFR, ERBB2, CDKN2A, TP53, TYMP, and TYMS. These FISH probes were used with control probes to distinguish among various kinds of chromosome abnormalities of number and structure.

RESULTS

FISH abnormalities were observed in 12 (80%) of 15 patients with pancreatic cancer: 5 of 5 patients with acinar cell carcinoma, 5 of 5 patients with ductal adenocarcinoma, and 2 (40%) of 5 patients with islet cell carcinoma. All 3 specimens of pancreatic tissue without neoplasia had normal FISH results. Gains of CTNNB1 due to trisomy 3 occurred in each tumor with acinar cell carcinoma but in none of the other tumors in this study. FISH abnormalities of all other cancer genes studied were observed in all forms of pancreatic tumors in this investigation.

CONCLUSION

FISH abnormalities of CTNNB1 due to trisomy 3 were observed only in acinar cell carcinoma. FISH abnormalities of genes implicated in familial cancer, tumor progression, and the 5-fluorouracil pathway were common but were not associated with specific types of pancreatic cancer.

Four cases of pancreatic acinar cell carcinoma treated with gemcitabine or S-1 as a single agent

Pancreatic acinar cell carcinoma (ACC) is a comparatively rare tumor and account for approximately 1% of all cases of pancreatic cancer. Clinical presentation is usually related to either local spread or metastasis. The clinical features, especially those related to the prognosis and treatment outcomes, have not yet been fully clarified. There are no established treatments for unresectable pancreatic ACC. We administered gemcitabine monotherapy to four patients with ACC; however, the results were not satisfactory. Disease control without obvious tumor shrinkage was observed in one patient. Another patient showed severe renal damage caused by gemcitabine. On the other hand, fluoropyrimidine-based chemotherapy may have some activity against this tumor, because one of the three patients who received S-1 as second-line chemotherapy showed a partial response. Prospective clinical trials are necessary to confirm the effectiveness of fluoropyrimidine for the treatment of pancreatic ACC.

Curative resection of a primarily unresectable acinar cell carcinoma of the pancreas after chemotherapy

Background

Acinar cell carcinoma (ACC) represents only 1–2% of pancreatic cancers and is a very rare malignancy. At the time of diagnosis only 50% of the tumors appear to be resectable. Reliable data for an effective adjuvant or neoadjuvant treatment are not available.

Case presentation

A 65-year old male presented with obstructive jaundice and non-specific upper abdominal pain. MRI-imaging showed a tumor within the head of the pancreas concomitant with Serum-Lipase and CA19-9. During ERCP, a stent was placed. Endosonographic fine needle biopsy confirmed an acinar cell carcinoma. Laparotomy presented an locally advanced tumor with venous infiltration that was consequently deemed unresectable. The patient was treated with five cycles of 5-FU monotherapy with palliative intention. Chemotherapy was well tolerated, and no severe complications were observed. Twelve months later, the patient was in stable condition, and CT-scanning showed an obvious reduction in the size of the tumor. During further operative exploration, a PPPD with resection of the portal vein was performed. Histopathological examination gave evidence of a diffuse necrotic ACC-tumor, all resection margins were found to be negative. Eighteen months later, the patient showed no signs of recurrent disease.

Conclusion

ACC responded well to 5-FU monochemotherapy. Therefore, neoadjuvant chemotherapy could be an option to reduce a primarily unresectable ACC to a point where curative resection can be achieved.

Current diagnosis and management of unusual pancreatic tumors

BACKGROUND

The finding of a solid or cystic mass in the pancreas is becoming more common secondary to the increasing use of cross-sectional imaging and the improved sensitivity of such studies for the detection of pancreatic abnormalities. Because of the aggressive natural history of pancreatic cancer, this has caused concern that all pancreatic abnormalities may be cancer as well as confusion over proper diagnostic and treatment algorithms. This review provides an overview of the natural history, diagnostic considerations, and treatment recommendations for the less common tumors of the pancreas which can be misinterpreted as pancreatic cancer including: solid pseudopapillary tumors (SPT), acinar cell carcinoma (ACC), lymphoplasmacytic sclerosing pancreatitis (LPSP), primary pancreatic lymphoma (PPL), and metastatic renal cell carcinoma to the pancreas.

DATA SOURCES

A Medline search was conducted to identify studies investigating the clinicopathologic features, molecular genetics, pathogenesis, diagnosis, and treatment of SPT, ACC, LPSP, PPL, and pancreatic metastases.

CONCLUSIONS

It is often possible to obtain an accurate pretreatment diagnosis for these unusual pancreatic tumors and to successfully differentiate them from the more common pancreatic malignancies.

Acinar cell carcinoma arising from an ectopic pancreas

We herein report a rare case of ectopic pancreatic acinar cell carcinoma (ACC) which presented as a submucosal tumor of the pylorus. A 73-year-old man came to our hospital presenting with epigastralgia. Esophago-gastroduodenal endoscopy showed no mucosal lesions, but a submucosal tumor was observed around the pylorus. Abdominal computed tomography revealed two round masses. One was located in the pylorus, while the other was found between the portal vein and the inferior vena cava. An examination of a biopsy specimen was inconclusive. We diagnosed a gastrointestinal stromal tumor or malignant lymphoma preoperatively, and decided to perform an operation in order to confirm the diagnosis and select the optimal treatment. Intraoperatively, the mass in the pylorus invaded the pancreatic head, and the lymph node in the hepatoduodenal ligament was swollen. We performed a pancreaticoduodenectomy as a radical excision. The resected specimen showed the 7.6 x 4.9-cm size tumor to mainly originate from the pylorus. Histopathologically, the tumor was identified as pancreatic ACC with lymph node metastasis. The tumor cells were labeled by immunohistochemical staining for alpha1-antitrypsin. Because of the tumor location, we considered the tumor to have originated from the ectopic pancreatic tissue in the stomach. This is only the second case of ACC originating from an ectopic pancreas reported in the literature.

Acinar cell carcinoma arising from an ectopic pancreas

We herein report a rare case of ectopic pancreatic acinar cell carcinoma (ACC) which presented as a submucosal tumor of the pylorus. A 73-year-old man came to our hospital presenting with epigastralgia. Esophago-gastroduodenal endoscopy showed no mucosal lesions, but a submucosal tumor was observed around the pylorus. Abdominal computed tomography revealed two round masses. One was located in the pylorus, while the other was found between the portal vein and the inferior vena cava. An examination of a biopsy specimen was inconclusive. We diagnosed a gastrointestinal stromal tumor or malignant lymphoma preoperatively, and decided to perform an operation in order to confirm the diagnosis and select the optimal treatment. Intraoperatively, the mass in the pylorus invaded the pancreatic head, and the lymph node in the hepatoduodenal ligament was swollen. We performed a pancreaticoduodenectomy as a radical excision. The resected specimen showed the 7.6 x 4.9-cm size tumor to mainly originate from the pylorus. Histopathologically, the tumor was identified as pancreatic ACC with lymph node metastasis. The tumor cells were labeled by immunohistochemical staining for alpha1-antitrypsin. Because of the tumor location, we considered the tumor to have originated from the ectopic pancreatic tissue in the stomach. This is only the second case of ACC originating from an ectopic pancreas reported in the literature.

Acinar cell carcinoma of the pancreas: clinical analysis of 115 patients from Pancreatic Cancer Registry of Japan Pancreas Society

OBJECTIVES

Acinar cell carcinoma (ACC) of the pancreas is a rare tumor, and many aspects remain unclear because no large-scale clinical studies have been conducted.

METHODS

The present study investigated the clinical characteristics, treatment, and therapeutic outcomes of 115 patients registered in the Pancreatic Cancer Registry of the Japan Pancreas Society, and therapeutic plans were reviewed.

RESULTS

Although ACC has been associated with advanced stage and poor prognosis, this tumor was resectable in 76.5% of the patients, and the 5-year survival rate after resection was favorable, being 43.9%.

CONCLUSIONS

Confirming the diagnosis of ACC preoperatively is difficult, but this diagnosis should be kept in mind while planning surgery for ordinary pancreatic cancer. Once the diagnosis has been confirmed, a possibility of surgical resection should be pursued to achieve better prognosis. If ACC is unresectable or recurrent, chemotherapy is likely to prove useful. Multidisciplinary therapy centering on the role of surgery will need to be established.

Less common neoplasms of the pancreas

Recently, there has been an increased recognition of neoplasms of the pancreas other than ductal adenocarcinoma. Although not as well studied or characterized as pancreatic adenocarcinoma there are many distinct lesions which exhibit diverse biological behaviors and varying degrees of malignancy. These lesions include: endocrine neoplasms, cystic tumors, solid pseudopapillary tumors, acinar cell carcinoma, squamous cell carcinoma, primary lymphoma of the pancreas, and metastatic lesions to the pancreas. These less common neoplasms are being diagnosed more frequently as the number and sensitivity of diagnostic imaging studies increase. This review article discusses the clinical course, diagnosis, and treatment of these less common, but quite relevant, neoplasms of the pancreas.