Acinar Cell Carcinoma of the Pancreas: A Literature Review and Update

Rare tumours of the pancreas: monocentric study

PURPOSE

The biology of rare pancreatic tumours, which differs from that of ductal pancreatic cancer, requires increased attention. Although the majority of rare pancreatic tumours are benign, it is difficult to decide whether an invasive component exists without complete removal of the lesion, despite considerable progress in diagnosis. We are investigating a large cohort of patients with histologically confirmed epithelial non-ductal non-neuroendocrine neoplasms of the pancreas.

METHODS

Here we analyze long-term survival from patients, who underwent resection of histologically confirmed epithelial non-ductal non-neuroendocrine neoplasms of the pancreas. At our department between Jan 1st, 1999, and Dec 31st, 2019. The median follow-up was 61 (range 0-168) month. All statistical analyses were performed using SPSS 26.0 (IBM, Chicago, IL, USA) software.

RESULTS

46 patients (48%) were followed up for more than 5 years, 18 patients (19%) for more than 10 years. The 5-year and 10-year survival rates for rare non-invasive pancreatic tumours were 72% and 55% respectively. The proportion of rare tumour entities (non-ductal and non-neuroendocrine) increased continuously and statistically significantly (p = 0.004) from 4.2 to 12.3% in our clinic between 1999 and 2019. If there is no invasive growth yet, there is a varying risk of malignant degeneration in the course of the disease. Therefore, the indication for pancreatic resection is still the subject of discussion.

CONCLUSION

The long-term prognosis of rare epithelial pancreatic tumours after R0 resection-even if they are already malignant-is much better than that of ductal pancreatic cancer.

Successful Treatment of an Acinar Pancreatic Carcinoma in an Inland Bearded Dragon (Pogona vitticeps): A Case Report

An adult, 362 g, male, intact inland bearded dragon (Pogona vitticeps) was admitted to a veterinary clinic due to a temporary cloacal prolapse and a two-week history of reduced overall condition and forage intake. Physical examination revealed an approximately 2 × 1 cm round-shaped, rigid intracoelomic tissue mass. Multiple sand deposits were present on the cloacal mucous membranes, though no signs of cloacal prolapse were present. The lizard was otherwise responsive but showed reduced body tension and movement behavior. Initial fecal examination revealed a high-grade oxyuriasis. A 2 × 1.5 cm sized intracoelomic, well-vascularized, round-shaped mass was subsequently visualized by ultrasonography. After a two-day stabilization therapy, the intracoelomic mass was removed by performing a standard ventral coeliotomy under general anesthesia. Histopathological examination of the excised mass revealed an acinar pancreatic adenocarcinoma with infiltration of the peritumorous connective soft tissue. The lizard remained at the clinic for a further seven days. Its postsurgical condition improved slowly. However, the lizard started regular forage intake 10 days after surgery, and general behavior enhanced constantly within the following three weeks. The animal was presented for a follow-up six weeks after surgery, showing bright and alert behavior with no signs of disease or illness. The lizard was re-examined 20 months after the initial presentation due to a reduced overall condition and reduced food intake. Blood chemistry evaluation revealed markedly decreased protein parameters, and moderate ascites was identified ultrasonographically. A distinct association with the preceding neoplastic disease could not be made, and the lizard returned to its regular condition under supportive therapy within three weeks. To the authors' knowledge, this is the first report of successful treatment of a pancreatic carcinoma in a bearded dragon.

Radiotherapy in the management of rare gastrointestinal cancers: A systematic review

The aim of this analysis is to assess radiotherapy's role and technical aspects in an array of rare gastrointestinal (GI) cancers for adult patients. Collection data pertaining to radiotherapy and digestive rare cancers were sourced from Medline, EMBASE, and Cochrane Library. Preoperative chemoradiotherapy improved outcomes for patients with esophageal undifferentiated carcinoma compared with esophageal salivary gland types of carcinomas. For rare gastric epithelial carcinoma, perioperative chemotherapy is the common treatment. Adjuvant chemoradiotherapy showed no benefice compared with adjuvant chemotherapy for duodenal adenocarcinoma. Small bowel sarcomas respond well to radiotherapy. By analogy to anal squamous cell carcinoma, exclusive chemoradiotherapy provided better outcomes for patients with rectal squamous cell carcinoma. For anal adenocarcinoma, neoadjuvant chemoradiotherapy, followed by radical surgery, was the most effective regimen. For pancreatic neuroendocrine tumors, chemoradiotherapy can be a suitable option as postoperative or exclusive for unresectable/borderline disease. The stereotactic body radiotherapy (SBRT) is a promising approach for hepatobiliary malignancy. Radiotherapy is a valuable option in gastrointestinal stromal tumors (GIST) for palliative intent, tyrosine kinase inhibitors (TKIs) resistant disease, and unresectable or residual disease. Involved field (IF) radiotherapy for digestive lymphoma provides good results, especially for gastric extranodal marginal zone lymphoma (MALT). In conclusion, radiotherapy is not an uncommon indication in this context. A multidisciplinary approach is needed for better management of digestive rare cancers.

Rare Solid Pancreatic Lesions on Cross-Sectional Imaging

Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.

CELA3B immunostaining is a highly specific marker for acinar cell carcinoma of the pancreas

Chymotrypsin-like elastase family member 3B (CELA3B, elastase-3B) is a pancreatic enzyme with digestive function in the intestine. Since RNA analyses of normal tissues suggest that CELA3B expression is limited to the pancreas, the potential diagnostic utility of CELA3B immunohistochemistry for the distinction of pancreatic from extrapancreatic cancers and in the distinction of acinar cell carcinoma from ductal adenocarcinoma was assessed. CELA3B expression was successfully analyzed in 13,223 tumor samples from 132 different tumor types and subtypes as well as 8 samples each of 76 different normal tissue types by immunohistochemistry in a tissue microarray format (TMA). In normal tissues, CELA3B immunostaining was only seen in acinar cells and in a fraction of ductal cells of the pancreas as well as on some apical membranes of surface epithelial cells of the intestine. Among tumors, CELA3B immunostaining was seen in 12 of 16 (75%) acinar cell carcinoma of the pancreas including 6 cases with strong staining (37.5%) as well as in 5 of 13,207 other tumors (0.04%). These included 1.2% of 91 adenoid cystic carcinomas, 1.2% of 246 mucoepidermoid carcinomas and 0.8% of 127 acinic cell carcinomas of salivary glands. Our data show a good sensitivity (75%) and a high specificity (99.9%) of CELA3B immunohistochemistry for diagnosing acinar cell carcinoma of the pancreas.

A case of unresectable ectopic acinar cell carcinoma developed in the portal vein in complete response to FOLFIRINOX therapy

A 56-year-old man presented to our hospital for close examination of a mass in the portal vein. CT showed a homogeneously enhanced mass occupying the portal vein. No other lesions suggestive of a primary tumor were detected. Endoscopic ultrasound-guided fine-needle aspiration revealed that the tumor was pathologically acinar cell carcinoma (ACC) based on the positive staining for both BCL-10 and trypsin. He was diagnosed with an ectopic ACC developed in the portal vein. Because the tumor invaded secondary branches of the right intrahepatic portal vein and the superior mesenteric vein, it was considered surgically un-resectable. Therefore, chemotherapy with gemcitabine plus nab-paclitaxel (GEM + nab-PTX) was started. After 2 courses, CT showed progressive disease, so the regimen was switched to FOLFIRINOX. After starting treatment with FOLFIRINOX, the tumor shrank gradually. After 29 courses, CT scan eventually showed disappearance of the tumor and complete response was achieved. After 34 courses, the chemotherapy was discontinued. Since then, the patient has been recurrence-free for 5 years. Our English literature review yielded 6 cases, including this case, of un-resectable ACC in which complete response was achieved by chemotherapy. Our case suggest that platinum-based regimen might be an effective therapy for un-resectable ACC, including ectopic ACC.

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.

Acinar cell carcinoma with PRKAR1A and PTEN alterations and paraneoplastic panniculitis

Pancreatic acinar cell carcinoma is a rare type of pancreatic malignancy, which can be confused with pancreatic neuroendocrine neoplasm. Here, we describe a woman in her 80s who presented with abdominal pain and bilateral lower extremity panniculitis. She underwent surgery for a presumed diagnosis of neuroendocrine tumour with PTEN and PRKAR1A alterations; 19 months, later, a recurrence of her pancreatic malignancy was discovered. The patient underwent repeat resection and this time immunohistochemical staining confirmed the diagnosis of acinar cell carcinoma. Staining for acinar cell carcinoma should be prompted based on clinical suspicion in context of PTEN or PRKAR1A mutation when appropriate.

Undifferentiated Pancreatic Carcinomas, Clinical Features and Therapeutic Options: What We Know

Undifferentiated pancreatic carcinomas are rare malignant tumors of the pancreas that are very aggressive and challenging to diagnose. The WHO categorizes them into undifferentiated osteoclast-like giant cell, sarcomatoid, and rhabdoid pancreatic carcinomas. Patients present with nonspecific symptoms such as jaundice, vague abdominal or back pain and itchy skin. Their histological characteristics include positive pan-cytokeratin mononuclear pleomorphic cells, osteoclast-like giant cells and CD68. Patients may have KRAS, TP53 and SMAD4 alterations, homozygous deletions of CDKN2A and CDKN2B, as well as INI1 deficiency. Surgical resection is the only curative treatment. Patients may benefit from postoperative adjuvant therapy. There are no widely accepted guidelines specific to this type of tumor; however, some chemotherapy regimens may be promising. The patient prognosis is mostly poor, especially in patients with unresectable tumors. However, several studies have shown patients achieving long-term survival with adjuvant therapy. In conclusion, although undifferentiated pancreatic carcinoma is rare and very aggressive, there is still potential for improved patient survival with proper diagnosis and treatment.

Pancreatic acinar cell carcinoma: A comprehensive review

Acinar cell carcinoma (ACC) is a rare pancreatic malignancy with distinctive clinical, molecular, and morphological features. The long-term survival of ACC patients is substantially superior to that of pancreatic adenocarcinoma patients. As there are no significant patient series about ACCs, our understanding of this illness is mainly based on case reports and limited patient series. Surgical resection is the treatment of choice for patients with the disease restricted to one organ; however, with recent breakthroughs in precision medicine, medicines targeting the one-of-a-kind molecular profile of ACC are on the horizon. There are no standard treatment protocols available for people in which a total surgical resection to cure the condition is not possible. As a result of shared genetic alterations, ACCs are chemosensitive to agents with activity against pancreatic adenocarcinomas and colorectal carcinomas. The role of neoadjuvant or adjuvant chemoradiotherapy has not been established. This article aims to do a comprehensive literature study and present the most recent information on acinar cell cancer.

Basic pancreatic lesions: Radiologic-pathologic correlation

The basic pancreatic lesions include location, size, shape, number, capsule, calcification/calculi, hemorrhage, cystic degeneration, fibrosis, pancreatic duct alterations, and microvessel. One or more basic lesions form a kind of pancreatic disease. As recognizing the characteristic imaging features of pancreatic basic lesions and their relationships with pathology aids in differentiating the variety of pancreatic diseases. The purpose of this study is to review the pathological and imaging features of the basic pancreatic lesions.

Defining the role of systemic therapy in resectable pancreatic acinar cell carcinoma

INTRODUCTION

Following resection of pancreatic acinar cell carcinoma (PACC) distant recurrence remains high. We utilized the national cancer database (NCDB) to evaluate the role of systemic therapy in early-stage resected PACC.

METHODS

We queried the NCDB registry from 2004 to 2015 for patients with pathologic stage I-IIB PACC. For each stage, patients who underwent surgery alone (SA) were compared to patients who received systemic and/or radiation therapy in addition to surgery (surgery + therapy [S + T]).

RESULTS

A total of 271 patients (101 pI, 81 pIIA, and 89 pIIB) were analyzed. Of all clinically node positive patients (n = 41), the majority (n = 32, 78%) had node-positive disease at resection (pIIB). SA was performed in 112 patients (41.3%), whereas 159 (58.7%) patients received S + T. There was no difference in overall survival (OS) between S + T and SA with respect to pI or pIIA disease. In pIIB disease, S + T was associated with improved OS compared to SA (34.9 vs. 16.9 months, p = 0.031). Single-agent chemotherapy was associated with improved OS for pIIB disease when compared to SA (hazard ratio: 0.38, 95% confidence interval: 0.16, 0.83).

CONCLUSION

In resectable PACC, the survival benefit of adjuvant therapy is limited to pathologic stage IIB disease. This benefit is evident even in patients treated with single-agent chemotherapy.

Carboxypeptidase A1 (CPA1) Immunohistochemistry Is Highly Sensitive and Specific for Acinar Cell Carcinoma (ACC) of the Pancreas

Carboxypeptidase A1 (CPA1) is a zinc metalloprotease that is produced in pancreatic acinar cells and plays a role in cleaving C-terminal branched-chain and aromatic amino acids from dietary proteins. This study assessed the utility of immunohistochemical CPA1 staining for diagnosing pancreatic acinar cell carcinoma (ACC). A total of 12,274 tumor samples from 132 different tumor types and subtypes as well as 8 samples each of 76 different normal tissue types were interpretable by immunohistochemistry in a tissue microarray format. CPA1 was strongly expressed in acinar cells of all normal pancreas samples but not in any other normal tissues. CPA1 immunostaining was detected in 100% of 11 pancreatic ACCs and 1 mixed acinar endocrine carcinoma, but absent in 449 pancreatic ductal adenocarcinomas, 75 adenocarcinomas of the ampulla Vateri, and 11,739 other evaluable cancers from 128 different tumor entities. A weak to moderate diffuse staining of epithelial and stromal cells of cancer tissues immediately adjacent to non-neoplastic pancreatic acinar cells often occurred and was considered to be caused by the diffusion of the highly abundant CPA1 from normal acinar cells that may have suffered some autolytic cell damage. In conclusion, our data show that CPA1 is a highly sensitive and largely specific marker for normal and neoplastic pancreatic acinar cells. CPA1 immunohistochemistry greatly facilitates the otherwise often difficult diagnosis of pancreatic ACC.

Rapid Response to the Combination of Lenvatinib and Sintilimab in a Pancreatic Acinar Cell Carcinoma Patient With Elevated Alpha-Fetoprotein: A Case Report

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.

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.

Complete response of locally advanced left-sided pancreatic cancer after modified FOLFIRINOX chemotherapy followed by conversion surgery: A case report

For years, neoadjuvant chemotherapy for locally advanced pancreatic cancer is being investigated and radical surgical resection with laparoscopic approach is getting up to speed. Pathological complete remission is known as a predictive marker for a good prognosis for various carcinomas. Although there are a few case reports about pathological complete remission, there has been no case report of pathological complete remission resulted from successful extensive resection by laparoscopic surgery after a neoadjuvant modified FOLFIRINOX chemotherapy. A 68-year-old male patient was admitted due to a palpable abdominal mass which turned out to be 16-cm-sized huge locally advanced left-sided pancreatic cancer with possible stomach, left adrenal gland, left kidney, and colon invasion. After administration of 10th modified FOLFIRINOX chemotherapy, the tumor had decreased and he underwent laparoscopic radical distal pancreatectomy with splenectomy, left adrenalectomy, wedge resection of stomach, and segmental resection of transverse colon. Although patient had a postoperative micro-abscess around the colon anastomosis site, he was successfully managed with conservative treatment and discharged on 12 days postoperatively. The final pathology reported complete tumor regression. We hereby emphasize the oncologic significance of neoadjuvant chemotherapy in huge left-sided pancreatic cancer and the potential role of laparoscopic conversion surgery.

Clinical Analysis of Acinar Cell Carcinoma of the Pancreas: A Single-Center Experience of 45 Consecutive Cases

Backgrounds:

Acinar cell carcinoma of the pancreas is a rare malignancy, and its features remain unclear. We aimed to analyze the clinical characteristics, treatment and prognosis of acinar cell carcinoma with our institutional case series.

Methods:

Patients diagnosed with acinar cell carcinoma in our hospital between 2005 and 2019 were reviewed. Investigations on clinicopathological features, treatment details and long-term survival were performed.

Results:

A total of 45 pathologically confirmed acinar cell carcinomas were identified. The median age at diagnosis was 58 years with a male-to-female ratio of 3.1:1. There were 24 (53.3%) localized, 5 (11.1%) locally advanced and 16 (35.6%) metastatic cases, with a pancreatic head-to-body/tail ratio of 1:1.4 for all the primary lesions. In the localized group, there were 10 pancreatoduodenectomy, 12 distal pancreatectomy, 1 total pancreatectomy, and 1 distal pancreatectomy combined with proximal gastrectomy. Among the locally advanced and metastatic cases, 13 patients received chemotherapy, 1 received concurrent radiochemotherapy, 1 underwent synchronous resection of primary tumor and liver metastasis, 1 underwent palliative operation, 1 underwent exploratory laparotomy, and 4 required no treatment. The median overall survival of this series was 18.9 months with a 5-year survival rate of 19.6%. Moreover, the resected acinar cell carcinoma patients were associated with prolonged survival compared with the unresected cases (36.6 vs. 8.5 months, P < 0.001).

Conclusions:

Surgical resection could improve the long-term survival of acinar cell carcinoma patients, which might also improve the prognosis of selected metastatic cases. Large-scale studies are needed to further clarify the biological behavior and clinical features, and to seek the optimal treatments.

Pancreatic acinar cell carcinoma: A multi-center series on clinical characteristics and treatment outcomes

BACKGROUND

Acinar cell carcinoma (ACC) is a very rare tumor of the exocrine pancreas, representing less than 1% of all pancreatic malignancies. The majority of data regarding ACC are limited to small case series.

METHODS

This is a retrospective study conducted at a large healthcare system from 1996 to 2019. Patients with pathologically confirmed ACC were included, and demographic data, tumor characteristics, and treatment outcomes were abstracted by chart review. Survival curves were obtained by using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Sixty-six patients with ACC were identified. The median patient age at diagnosis was 64, and 42% presented with metastatic disease. The majority presented with abdominal pain or pancreatitis (69%), and laboratory parameters did not correlate with tumor size, metastatic disease, or survival. Several somatic abnormalities were noted in tumors (BRCA2, TP53, and mismatch-repair genes). In patients with localized disease that underwent resection, the median time to develop metastatic lesions was 13 months. The median overall survival (OS) was 24.7 months from diagnosis, with a survival difference based on metastatic disease at diagnosis (median 15 vs 38 mos). Surgery was associated with improved survival in non-metastatic cases (p = 0.006) but not metastatic cases (p = 0.22), and chemotherapy showed OS benefit in metastatic disease (p < 0.01). Patients with metastatic ACC treated after 2010 utilized more platinum-based agents, and there was a OS benefit to FOLFOX or FOLFIRINOX chemotherapy compared to gemcitabine or capecitabine-based regimens (p = 0.006).

CONCLUSION

Pancreatic ACC patients often present with advanced disease. Surgery was associated with survival benefit among patients presenting with localized disease. The use of FOLFOX or FOLFIRINOX chemotherapy regimens was associated with improved OS in metastatic patients. These data add to our knowledge in this rare malignancy, and improves understanding about the genomic underpinnings, prognosis and treatment for acinar cancers.

Extended pancreato-duodenectomy coupled with adjuvant chemotherapy for SMARCB1/INI1 deficient pancreatic carcinoma: A case report and literature review

Introduction

SMARCB1/INI1 gene deletion appears to be associated with a rare, malignant and aggressive form of pancreatic carcinoma whose diagnosis is challenging. Our objective is to illustrate that the tumor may masquerade as a duodenal papillary carcinoma, be difficulty to identify on diagnostic imaging and that making an accurate diagnosis may be challenging, however surgical resection may be possible.

Case report

We present a case of a 24-year old male patient presenting with jaundice and itchy skin, elevated TBIL, AST, ALP and CA125. A 2.2 × 1.7 cm pancreatic nodule, later diagnosed as a SMARCB1/INI deficient pancreatic carcinoma was detected on Endoscopic Ultrasound - Fine Needle Aspiration (EUS-FNA). The patient was successfully treated with extended pancreato-duodenectomy coupled with adjuvant chemotherapy, a 7 × 5 × 5 cm tumor resected.

Discussion

SMARCB1/INI deficient pancreatic carcinoma has been reported in couple of other articles. However, unlike other cases, in our case identification and accurate assessment of the tumor was particularly difficulty both on imaging and during operation. Our patient has thus far had a positive outcome with no recurrence.

Conclusion

For rare forms of pancreatic carcinoma, identification and assessment of the tumor size may be challenging on imaging and during operation. However, careful assessment should be performed before ruling out surgical resection. Furthermore, adjuvant chemotherapy may be beneficial to the patient.

•

SMARCB1/INI gene deletion is associated with undifferentiated carcinoma characterized by malignancy and aggressiveness.

•

This case highlights the ambiguity in manifestation and diagnosis of SMARCB1 pancreatic carcinoma.

•

Assessment and accurate determination of the tumor size may not be possible on imaging and preoperatively.

•

Adjuvant chemotherapy may be beneficial to patient prognosis post-surgery.

Acinar cell carcinoma in childhood: A case report of a very rare tumor

Introduction

Pancreatic tumors are reported rarely in childhood and represent an extremely rare entity in Pediatric Oncology. One of the least common types of pediatric pancreatic tumor is acinar cell carcinoma (ACC). We aim to present a rare case of ACC and the difficulties we faced during diagnosis and treatment.

Patient and Methods

An 8-year old girl presented with jaundice. Workup revealed a tumor originating from the head of the pancreas with multiple metastatic lesions in her liver. Evaluation of tumor markers revealed elevated levels of AFP. Pathology report was indicative of acinar cell carcinoma of the pancreas.

Results

After consulting the EXPeRT group (European Cooperative Study Group for Pediatric Rare Tumors), chemotherapy was initiated. Partial response was observed after the first 4 courses with decrease of AFP levels. While planning her surgery, AFP elevated and a second-line course of chemotherapy was administered. Our patient underwent Whipple’s Duodenopancreatectomy with partial metastasectomy. Although the postoperative period was uneventful, AFP continued to rise even after postoperative chemotherapy was administered. There were signs of metastatic disease progression. Our patient received a third-line regimen with no improvement. She received local radiotherapy and a next-line chemotherapy course. Local relapse and metastatic disease progression placed our patient in palliative care. She passed away nine months after the initial diagnosis.

Conclusions

Acinar cell carcinoma of the pancreas is a rare type of pediatric cancer with very challenging diagnosis and treatment. Cooperation at the European level and multicenter management of those rare cases is vital for the optimum outcome.

Rare case of acinar cell carcinoma with multiple lesions in the pancreas

We present the first case of pancreatic acinar cell carcinoma (PACC) with multiple lesions. A 55‐year‐old man with a pancretic tail mass on abdominal computed tomography (CT) was admitted to our hospital. Endoscopic ultrasound (EUS) showed a hypoechoic mass, and EUS‐guided fine‐needle aspiration (EUS‐FNA) revealed the mass to be PACC. The patient underwent distal pancreatectomy, and two masses were identified in the pancreatic tail and body. Histologically, both masses had tumor cells similar to acinar cells and were positive for BCL‐10. The patient was thus diagnosed with synchronous PACC. Ten months after the surgery, abdominal CT revealed a mass in the remnant pancreas. EUS showed a hypoechoic mass, and EUS‐FNA determined it to be PACC. The patient underwent total remnant pancreatectomy. The histological imaging results were similar to those of the first resection. Finally, the patient was diagnosed with synchronous and metachronous PACC. The possibility of multiple occurrences in the pancreas should be considered with PACC.

Acinar cell carcinoma of the pancreas: a clinicopathologic and cytomorphologic review

Acinar cell carcinoma (ACC) is a rare malignancy of the pancreas with unique clinical, molecular, and morphologic characteristics. Clinically, these cancers can present with hypersecretory syndrome caused by the release of lipase into the circulation. Surgical resection is the treatment of choice for patients with organ-confined disease; however, with recent advances in precision medicine, therapies targeting the distinct molecular profile of ACC are on the horizon. Cytomorphologic features of ACC have been well described in the literature; and in conjunction with available clinical data and appropriate ancillary studies, an accurate diagnosis can be rendered in most instances. The aim of the current article is to present a comprehensive review of ACC based on available literature while attempting to shed light on some of its key histologic and cytologic characteristics.

Long-term survival of two patients with recurrent pancreatic acinar cell carcinoma treated with radiofrequency ablation: A case report

BACKGROUND

Pancreatic acinar cell carcinoma (PACC) is a rare type of malignant pancreatic cancer that represents approximately 1% of all pancreatic neoplasms. Due to its very low incidence, only a few retrospective studies are available. Although surgery is the first choice for treatment, most patients experience recurrence (mainly in the liver) and there are no clear recommendations for patients with advanced disease.

CASE SUMMARY

We report two patients with PACC treated with surgery who experienced tumour recurrence in the liver. Patient 1 carried a germline mutation in the APC gene. Both patients were treated with gemcitabine plus oxaliplatin and gemcitabine plus capecitabine as first- and second-line therapies, respectively. After a favourable response to chemotherapy, the patients underwent radiofrequency ablation of the remaining liver metastases. For patient 1, we documented a relapse in the liver after a disease-free period of 9 mo, and treatment with gemcitabine plus capecitabine was restarted. The patient achieved a complete response, and he remains alive without evidence of disease recurrence after six years. After radiofrequency ablation, patient 2 experienced disease-free survival for 21 mo, when peritoneal relapse was diagnosed and treated with chemotherapy. The patient achieved a stable disease state for nearly two years; nevertheless, further progressive disease was documented, and he died seven years after the first relapse.

CONCLUSION

PACC presents different biological behaviours than pancreatic adenocarcinoma. Multidisciplinary treatment involving local ablative therapies may be considered for PACC.

The Unusual Suspects of the Pancreas-Understanding Pancreatic Acinar Cell Carcinomas and Adenomas

PURPOSE

Acinar cell carcinomas (ACC) and adenomas (ACA) of the pancreas are rare entities. Sufficient knowledge about occurrence and prognosis is scarce.

METHODS

A retrospective chart review of our database was performed for all patients who had undergone pancreatic surgery between 2006 and 2018. Results were compared to recent literature findings.

RESULTS

Nine patients were diagnosed with ACC and four patients with ACA of the pancreas in the study period. ACC patients were older and more often male than patients of the ACA group. ACC were mainly localized in the pancreatic head, whereas ACA were more often found in the distal pancreas. Tumor markers are not necessarily elevated, even in case of malignancy.

CONCLUSIONS

ACC and ACA are very rare pancreatic tumors. Both entities account for less than 1% of all pancreatic neoplasms. Diagnosis is challenging due to unspecific radiologic features and clinical symptoms. Nevertheless, a patient complaining of abdominal discomfort and an unclear hypodense pancreatic lesion should undergo surgical exploration.

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.

An unusual case of primary acinar cell carcinoma of the liver and its treatment

Acinar cell carcinoma (ACC) is an epithelial neoplasm characterized by morphological features similar to acinar cells found in exocrine glands. Most cases of hepatic ACC reveal evidence of pancreatic exocrine enzyme production and are considered to be metastatic from the pancreas. However, a small number of hepatic ACC cases have been reported in which the tumor is believed to have originated in the liver rather than being a metastatic lesion. In this report we present a case of primary ACC of the liver. A 59-year-old female with no significant past medical history presented with the chief complaint of abdominal pain. A computed tomography (CT) scan of the abdomen showed innumerable mass lesions throughout the liver, initially concerning for metastatic disease. Histopathologic morphology was most consistent with that of ACC, possibly of pancreatic origin. However, the CA 19-9 level was not elevated and no pancreatic lesions were detected on the CT scan. Similar to a previously reported case, the diagnosis of primary ACC of the liver was made based on: acinar cells seen on histology, findings on immunohistochemical staining, radiographic images of liver masses, and the absence of extrahepatic lesions. Previous case reports of primary ACC have differing hypotheses regarding this rare finding. One hypothesis suggests an ectopic origin of acinar cells within the liver. An alternative hypothesis proposes that hepatic and pancreatic cells are ontogenetically derived from a common progenitor cell, which is thought to result in hepatic cells differentiating into acinar cells. The patient was treated with gemcitabine and paclitaxel every 2 weeks for 8 months and then transitioned to every 3 weeks for better tolerance. The patient's symptoms significantly improved within the first 6 weeks of treatment. At the time of the preparation of this report, it has been 17 months since initiation of therapy, and follow-up imaging continues to demonstrate a dramatic decrease in both size and number of hepatic nodules. ACC's are rare tumors that are usually found in glandular tissues. Primary ACC of the liver is extremely rare with only a few cases having been reported. This article adds to the limited literature available on primary hepatic ACC.

Cystic Lesions of the Pancreas: Differential Diagnosis and Cytologic-Histologic Correlation

CONTEXT.—

Pancreatic cystic lesions (PCLs) are very common, and their detection is increasing with the advances in imaging techniques. Because of the major implications for management, distinguishing between neoplastic and nonneoplastic PCLs is critical. Neoplastic cysts with potential to progress into cancer include mucinous PCLs (intraductal papillary mucinous neoplasms and mucinous cystic neoplasms) and nonmucinous cysts (solid pseudopapillary tumors, serous cystic neoplasms, and neuroendocrine tumors with cystic degeneration). Nonneoplastic cysts with no risk of malignant transformation include pseudocysts, retention cysts, lymphoepithelial cysts, cystic pancreatic lymphangioma, and duplication cyst/ciliated foregut cysts. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology with cyst fluid analysis in the diagnosis of PCLs has evolved during the last decade; however, a definitive diagnosis on cytologic specimens is hampered by the sparse cellularity and can be challenging. EUS-FNA can play an important role to differentiate low-risk from high-risk pancreatic cysts and to distinguish between patients with cysts who need clinical follow-up versus those who require surgery.

OBJECTIVE.—

To provide an integrative approach to diagnose pancreatic cystic lesions using EUS-FNA cytology and cyst fluid analysis, along with clinical, radiologic, histologic, genetic, and molecular characteristics.

DATA SOURCES.—

The review and analysis of the latest literature describing pancreatic cystic lesions.

CONCLUSIONS.—

Accurate diagnosis of PCLs requires a multidisciplinary and multimodal team approach, including the integration of clinical findings, imaging, cytology, cyst fluid analysis, and molecular testing.

[The histological and immunohistochemical diagnosis of solid pseudopapillary neoplasm of the pancreas and its differential diagnosis]

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of uncertain histogenesis, described separately by Gruber and Frantz, that accounts for between approximately 1% and 3% of pancreatic neoplasms. It is characterized by a cystic and solid pattern of growth patterns with formation of pseudopapillae. It occurs primarily in young women, although cases in children and older patients and men have been reported. The tumor is of low-grade malignant potential, as the majority of the cases are cured by simple but complete surgical resection. Knowledge of the unique morphologic characteristics of this neoplasm is essential for the correct diagnosis. We review herein the pathologic and immunohistochemical features of this neoplasm and its differential diagnosis with other pancreatic tumors.

Pancreatic panniculitis as a presentation symptom of acinar cell carcinoma

Pancreatic panniculitis is a rare skin manifestation associated with pancreatic conditions. This condition has similar characteristics to those of other panniculitis types and its course parallels the triggering condition and may occasionally precede it. We report the case of a female patient with asymptomatic pancreatic panniculitis; the etiologic study identified a pancreatic acinar cell carcinoma with liver metastases.

Pancreatic acinar cell carcinoma-case report and literature review

Background

Pancreatic acinar cell carcinoma (ACC) is a rare tumor that constitutes 1% of all pancreatic neoplasms. Pancreatic ACC has unique characteristics in terms of biological behavior, imaging and prognosis.

Case presentation

The present study reported two cases of pancreatic ACC confirmed by postoperative pathology and both cases exhibited several different imaging features and laboratory test results. Both cases had approximately 4 cm mass located in uncinate process of pancreas. Dilated intra- and extra-hepatic bile ducts was observed in one case, along with calcification. Heterogeneous enhancement of the tumor was exhibited in both patients with different intensities. Obstructive jaundice, elevated α-fetoprotein and CA 19–9 was found in one case, while the other case had normal liver function and tumor markers.

Conclusions

It was difficult to accurately diagnose pancreatic ACC before the operation despite its unique characteristics. Radical resection was the best treatment modality for resectable pancreatic ACC.

Curative distal pancreatectomy in patients with acinar cell carcinoma of pancreas diagnosed by endoscopic aspiration via esophago-jejunostomy: A successful case report

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This is a rare report of acinar cell carcinoma of pancreas diagnosed preoperatively.

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Accurate histological diagnosis was performed by endoscopic FNA via jejunal loop after gastrectomy.

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Accurate histological diagnosis is useful in the field of pancreatic surgery, especially in cases of rare or small malignant lesions.

Introduction

This is a case report on the advances in preoperative endoscopic-guided fine-needle-aspiration (FNA) diagnosis for pancreatic carcinoma to achieve a curative operation even in patients who have a history of total gastrectomy.

Case presentation

A 65-year-old man, who underwent total gastrectomy for gastric cancer 13 years ago, had discomfort in the left lateral abdomen. A 3-cm hypovascular mass accompanying a large distal pseudocyst in the pancreatic tail was observed on computed tomography. Endoscopic ultrasonography via elevation of the jejunal loop on esophago-jejunostomy also revealed similar lesions, and FNA for the proximal-side hypoechoic mass was successful. The cytological diagnosis with immunohistochemistry was acinar cell carcinoma of the pancreas. Distal pancreatectomy with splenectomy was successfully performed. Histology of the resected specimen also showed the acinar cell carcinoma, similar with preoperative cytology, which involved the splenic vein and had extra-pancreatic extension but no lymph node metastasis. The tumor stage was IIA by the 2009 UICC classification. He had no tumor relapse on imaging follow-up until 12 months after the operation.

Discussion

There have been marked technical advancements in endoscopic ultrasonography-guided diagnosis, including FNA, even in patients with prior digestive tract surgery. However, the risk of complication is still a concern. Accurate histological diagnosis is useful in the field of pancreatic surgery, especially in cases of rare or small malignant lesions.

Conclusion

Curative pancreatectomy was possible in a case of acinar cell carcinoma, a rare pancreatic malignancy, which was diagnosed by preoperative endoscopic FNA diagnosis via esophago-jejunostomy after previous total gastrectomy.

Rare Tumors and Lesions of the Pancreas

There are a few entities that account for most solid and cystic masses of the pancreas. The pancreas harbors a wide array of diseases, including adenocarcinoma, and its variants, such as anaplastic and adenosquamous carcinoma. Other neoplasms include acinar cell carcinoma, solid pseudopapillary tumor, and sarcomas. Benign lesions include hamartomas, hemangiomas, lymphangioma, and plasmacytoma. Isolated metastases include renal cell carcinoma, melanoma, and other carcinomas. Benign inflammatory conditions, such as autoimmune pancreatitis and groove pancreatitis can also mimic solid neoplasms of the pancreas.

Liver Metastases in Pancreatic Acinar Cell Carcinoma Treated with Selective Internal Radiation Therapy with Y-90 Resin Microspheres

Background

Pancreatic acinar cell carcinoma (PACC) is a rare tumor. Surgical resection is the treatment of choice when feasible, but there are no clear recommendations for patients with advanced disease. Liver-directed therapy with Y-90 selective internal radiation therapy (SIRT) has been used to treat hepatic metastases from pancreatic tumors. We describe a case of PACC liver metastases treated with SIRT.

Case Report

59-year-old man was admitted with an infiltrative, solid lesion in pancreatic tail diagnosed as PACC. Lymph nodes in the hepatic hilum were enlarged, and many metastatic liver nodules were observed. After partial pancreatectomy, the left and right lobes of the liver were separately treated with Y-90 resin microspheres. Follow-up imaging revealed that all hepatic nodules shrank by at least 50%, and 3 nodules disappeared completely. Lipase concentration was 8407 U/L at baseline, rose to 12,705 U/L after pancreatectomy, and declined to 344 U/L after SIRT. Multiple rounds of chemotherapy in the subsequent year shrank the hepatic tumors further; disease then progressed, but a third line of chemotherapy shrank the tumors again, 16 months after SIRT treatment.

Conclusion

SIRT had a positive effect on liver metastases from PACC. In conjunction with systemic therapy, SIRT can achieve sustained disease control.

A primary pure pancreatic-type acinar cell carcinoma of the stomach: a case report

Background

Acinar cell carcinoma represents only 1–2% of exocrine pancreatic neoplasms. On exceptionally rare occasions, primary acinar cell carcinoma can occur in ectopic locations. Herein, we report a case of pure pancreatic-type acinar cell carcinoma arising in the stomach.

Case presentation

A 54-year-old male presented with a gastric submucosal mass detected by endoscopic examination. Laparoscopic wedge resection was performed. Macroscopically, the 2.7 cm yellowish mass was located in the submucosa of the stomach. Microscopically, the tumor was well circumscribed and had a homogeneous acinar architecture. The tumor cells were small and had a minimal amount of cytoplasm. The nuclei of the tumor cells were round to oval with finely dispersed chromatin. The tumor cells were strongly positive for α1-antitrypsin, chymotrypsin, and α1-antichymotrypsin immunostaining, consistent with pancreatic exocrine differentiation. There was no clinical or radiologic evidence of primary pancreatic or head and neck tumors. After surgical resection of the tumor, there was no recurrence or metastasis during 33 months follow-up.

Conclusion

In this report, we have presented a rare case of primary pure pancreatic-type acinar cell carcinoma arising in the stomach and suggest that it could be helpful if the pathologist were aware that pancreatic-type acinar cell carcinoma could arise in the stomach as a polypoid submucosal tumor in the routine diagnostic field of gastric endoscopy.

Neoadjuvant Chemotherapy and Appleby Procedure for Pancreatic Acinar Cell Carcinoma: A Case Report

Background: Acinar cell carcinoma is a rare form of pancreatic cancer, accounting for 1–2% of all cases of exocrine pancreatic neoplasms in adults. Due to its rarity, no randomized controlled trials have been performed to determine the optimal treatment options. As such, high-quality case reports and case series are needed to help guide clinicians in the management of this deadly disease.

Case Presentation: A 56-year-old Caucasian male presenting with abdominal pain and weight loss was diagnosed with stage III acinar cell carcinoma of the pancreatic body with celiac axis involvement. Although initially deemed unresectable, the patient responded favorably to nine cycles of 5-fluorouracil-based neoadjuvant chemotherapy. The tumor was successfully resected through distal pancreatectomy with en bloc splenectomy and en bloc celiac artery resection (Appleby procedure). Final pathology analysis showed negative resection margins and complete chemotherapeutic response within the pancreas, with residual tumor cells detected in only a single peripancreatic lymph node.

Conclusion: 5-fluorouracil-based chemotherapy may be a promising option for the neoadjuvant treatment of locally unresectable acinar cell carcinoma. With sufficient expertise, negative surgical resection margins are possible even with vascular involvement. Due to the generally poor prognosis associated with acinar cell carcinoma, such aggressive treatment measures are warranted.

Omental acinar cell carcinoma of pancreatic origin in a child: a clinicopathological rarity

A 6-year-old boy presented with a large subhepatic mass associated with pain abdomen. Exploration revealed a tumor in lesser omentum, completely separate from the normal pancreas that was excised completely. Histopathology suggested acinar cell carcinoma of pancreatic origin in an ectopic location. The child is well at 5 months follow-up.