Combined gastroscopic and laparoscopic resection of gastric metastatic adenosquamous carcinoma from lung: A case report

BACKGROUND Primary lung cancer is the leading cause of cancer-related death worldwide.Common metastatic sites include the brain,liver,bones,and adrenal glands.However,gastric metastases from lung cancer are rare.This case may be the first report of a combined gastroscopic and laparoscopic resection for gastric metasta-tic adenosquamous carcinoma(ASC).CASE SUMMARY We report a case of gastric metastasis from lung cancer.The patient was a 61-year-old Han Chinese female who first attended our hospital complaining of a per-sistent cough,leading to the diagnosis of advanced-stage lung adenocarcinoma.After more than four years of chemotherapy,the patient began to experience epi-gastric pain.Endoscopy was performed,and pathological examination of biopsy specimens confirmed that the gastric lesion was a metastasis from lung cancer.The lesion was successfully resected by combined gastroscopy and laparoscopy.Histopathological examination of the resected gastric specimen revealed ASC.CONCLUSION Gastric metastases from lung cancer are rare.Endoscopy,histological and immunohistochemical staining are useful for diagnosing metastatic lesions.Surgical management may provide extended survival in appropriately selected patients.

Gastric adenosquamous carcinoma with an elevated serum level of alpha-fetoprotein:A case report

BACKGROUND Gastric adenosquamous carcinoma(ASC)is rare and characterized by coexisting of adenocarcinoma andsquamous carcinoma within the same tumor.We present a female patient with gastric ASC who had an elevated serum level of alpha-fetopro-tein(AFP),which decreased to normal levels after a laparoscopic distant radical gastrectomy in a short period.The clinicopathological features in AFP-producing gastric cancer(GC)are discussed,as well as potentially available prognostic predi-ctors.CASE SUMMARY A 50-year-old woman presented to our department with a chief complain of a 6-mo history of bloating.She had no basic diseases including heart diseases and respiratory diseases,and she also denied any prior history of dysphagia,hematemesis,melena,rectal bleeding,hematochezia,or unintentional weight loss.Based on her symptoms,an esophagogastroduodenoscopy was performed,showing an annular cavity lesion 3 cm from the pylorus with a diameter of 6 cm.A biopsy of the lesion showed gastric ASC,whereas the pylorus biopsy showed normal mucosa.The patient further received an enhanced computed tomography scan which demonstrated an invasive lesion close to the pylorus with a still clear margin of the tumor to peripheral organs such as the pancreas and liver.Scattered lymph nodes were visible around,whereas no sign of liver metastasis was discovered.Serum tumor markers including carcinoembryonic antigen(CEA),cancer antigen 199(CA199),CA724,CA125,and CA242 were all normal,while the level of serum AFP increased to 172 ng/mL.A laparoscopic distant radical gastrectomy was performed after exclusion of surgical contraindications.Postoperative pathology results showed that the tumor displayed an ulcerated ASC phenotype(90%of medium to highly-differentiated squamous cell carcinoma,10%of poorly differentiated adenocarcinoma.Surprisingly,the serum level of AFP decreased to normal level on post operation day 5.The tumor cells were positive for CK5/6,p63,and CEA,and negative for AFP and Epstein-Barr encoding region.CONCLUSION We presented a rare case of gastric ASC with elevated serum AFP level,which may be new subtype of AFP-producing GC.Follow-up detection of serum AFP might be a useful tool to predict patient prognosis.

Surgical outcome of adenosquamous carcinoma of the pancreas

Adenosquamous carcinoma is rare,accounting for 3%-4% of all pancreatic carcinoma cases. These tumors are characterized by the presence of variable proportions of mucin-producing glandular elements and squamous components,the latter of which should account for at least 30% of the tumor tissue. Recently,several reports have described cases of adenosquamous carcinoma of the pancreas. However,as the number of patients who undergo resection at a single institute is limited,large studies describing the clinicopathological features,therapeutic management,and surgical outcome for adenosquamous carcinoma of the pancreas are lacking. We performed a literature review of English articles retrieved from Medline using the keywords 'pancreas' and 'adenosquamous carcinoma'. Additional articles were obtained from references within the papers identif ied by the Medline search. Our subsequent review of the literature revealed that optimal adjuvant chemotherapy and/or radiotherapy regimens for adenosquamous carcinoma of the pancreas have not been established,and that curative surgical resection offers the only chance for long-term survival. Unfortunately,the prognosis of the 39 patients who underwent pancreatic resection for adenosquamous carcinoma was very poor,with a 3-year overall survival rate of 14.0% and a median survival time of 6.8 mo. Since the postoperative prognosis of adenosquamous carcinoma of the pancreas is currently worse than that of pancreatic adenocarcinoma,new adjuvant chemotherapies and/or radiation techniques should be investigated as they may prove indispensible to the improvement of surgical outcomes.

Comparative study of ROR2 and WNT5a expression in squamous/adenosquamous carcinoma and adenocarcinoma of the gallbladder

AIM To investigate the expression and clinical pathological significance of ROR2 and WNT5a in gallbladder squamous/adenosquamous carcinoma (SC/ASC) and adenocarcinoma (AC). METHODS EnVision immunohistochemistry was used to stain for ROR2 and WNT5a in 46 SC/ASC patients and 80 AC patients. RESULTS Poorly differentiated AC among AC patients aged >45 years were significantly more frequent compared with SC/ASC patients, while tumors with a maximal diameter >3 cm in the SC/ASC group were significantly more frequent compared with the AC group. Positive ROR2 and WNT5a expression was significantly lower in SC/ASC or AC with a maximal mass diameter = 3 cm, a TNM stage of I + II, no lymph node metastasis, no surrounding invasion, and radical resection than in patients with a maximal mass diameter >3 cm, TNM stage., lymph node metastasis, surrounding invasion, and no resection. Positive ROR2 expression in patients with highly differentiated SC/ASC was significantly lower than in patients with poorly differentiated SC/ASC. Positive ROR2 and WNT5a expression levels in highly differentiated AC were significantly lower than in poorly differentiated AC. Kaplan-Meier survival analysis showed that differentiation degree, maximal mass diameter, TNM stage, lymph node metastasis, surrounding invasion, surgical procedure and the ROR2 and WNT5a expression levels were closely related to average survival of SC/ASC or AC. The survival of SC/ASC or AC patients with positive expression of ROR2 and WNT5a was significantly shorter than that of patients with negative expression results. Cox multivariate analysis revealed that poor differentiation, a maximal diameter of the mass >= 3 cm, TNM stage. or., lymph node metastasis, surrounding invasion, unresected surgery and positive ROR2 or WNT5a expression in the SC/ASC or AC patients were negatively correlated with the postoperative survival rate and positively correlated with mortality, which are risk factors and independent prognostic predictors. CONCLUSION SC/ASC or AC patients with positive ROR2 or WNT5a expression generally have a poor prognosis.

Fever as a first manifestation of advanced gastric adenosquamous carcinoma:A case report

Gastric adenosquamous carcinoma(ASC)is a rare type of gastric cancer.It is a mixed neoplasm,consisting of glandular cells and squamous cells.It is often diagnosed at an advanced stage,thus carrying a poor prognosis.We describe a case of a 73-year-old male,who presented with refractory fever and an intra-abdominal mass on imaging.He underwent a laparoscopic exploration followed by a successful totally laparoscopic total gastrectomy with D2 lymphadenectomy for gastric cancer.Postoperative pathology revealed primary gastric ASC(T4aN0M0).The patient received adjuvant radiotherapy and chemotherapy with S1 and is alive 20mo after surgery without recurrence.This is the first case of advanced gastric ASC with fever as the initial presentation treated with totally laparoscopic total gastrectomy reported in the English literature.

A huge adenosquamous carcinoma of the pancreas with sarcomatoid change:An unusual case report

Adenosquamous carcinoma rarely occurs in the pancreas,and is characterized by the presence of cellular components from both duct adenocarcinoma and squamous carcinoma.Here,we describe a rare case of pancreatic adenosquamous carcinoma with sarcomatous change.Immunohistochemistry showed that the sarcomatous lesion lost the epithelial marker and aberrantly expressed of acquired mesenchymal markers,which indicated that this special histological phenotype may be attributed to epithelial-mesenchymal transition.This case also indicated that a routine radical surgery without aggressive treatment strategies was still appropriate for adenosquamous carcinoma of the pancreas with sarcomatoid change.

Application of Unenhanced Computed Tomography Texture Analysis to Differentiate Pancreatic Adenosquamous Carcinoma from Pancreatic Ductal Adenocarcinoma

Objective:The objective of this study was to investigate the application of unenhanced computed tomography(CT)texture analysis in differentiating pancreatic adenosquamous carcinoma(PASC)from pancreatic ductal adenocarcinoma(PDAC).Methods:Preoperative CT images of 112 patients(31 with PASC,81 with PDAC)were retrospectively reviewed.A total of 396 texture parameters were extracted from AnalysisKit software for further texture analysis.Texture features were selected for the differentiation of PASC and PDAC by the Mann-Whitney U test,univariate logistic regression analysis,and the minimum redundancy maximum relevance algorithm.Furthermore,receiver operating characteristic(ROC)curve analysis was performed to evaluate the diagnostic performance of the texture feature-based model by the random forest(RF)method.Finally,the robustness and reproducibility of the predictive model were assessed by the 10-times leave-group-out cross-validation(LGOCV)method.

Adenosquamous carcinoma may have an inferior prognosis to signet ring cell carcinoma in patients with stages Ⅰ and Ⅱ gastric cancer

BACKGROUND Primary gastric adenosquamous carcinoma(ASC)is an exceedingly rare histological subtype.Gastric signet ring cell carcinoma(SRC)is a unique subtype with distinct tumor biology and clinical features.The prognosis of gastric ASC vs SRC has not been well established to date.We hypothesized that further knowledge about these distinct cancers would improve the clinical management of such patients.AIM To investigate the clinicopathological characteristics and prognosis of gastric ASC vs SRC.METHODS A cohort of gastric cancer patients was retrospectively collected from the Surveillance,epidemiology,and end results program database.The 1:4 propensity score matching was performed among this cohort.The clinicopathological features and prognosis of gastric ASC were compared with gastric SRC by descriptive statistics.Kaplan-Meier method was utilized to calculate the median survival of the two groups of patients.Cox proportional hazard regression models were used to identify prognostic factors.RESULTS Totally 6063 patients with gastric ASC or SRC were identified.A cohort of 465 patients was recruited to the matched population,including 370 patients with SRC and 95 patients with ASC.Gastric ASC showed an inferior prognosis to SRC after propensity score matching.In the post-matching cohort,the median cancer specific survival was 13.0(9.7-16.3)mo in the ASC group vs 20.0(15.7-24.3)mo in the SRC group,and the median overall survival had a similar trend(P<0.05).ASC and higher tumor-node-metastasis stage were independently associated with a poor survival,while radiotherapy and surgery were independent protective factors for improved prognosis.Subgroup survival analysis revealed that the prognosis of ASC was inferior to SRC only in stages I and II patients.CONCLUSION ASC may have an inferior prognosis to SRC in patients with stages I and II gastric cancer.Our study supports radiotherapy and surgery for the future management of this clinically rare entity.

Pancreatic adenosquamous carcinoma and intraductal papillary mucinous neoplasm in a CDKN2A germline mutation carrier

A 69-year-old woman from a kindred with familial atypical multiple mole melanoma and carrier of a germline mutation in CDKN2A, presented with abdominal pain caused by a solid-cystic pancreatic mass. The patient had an abdominal computed tomography three years before in which there was no evidence of pancreatic lesion. The endoscopic ultrasound guided fine needle aspiration showed adenocarcinoma with squamous component. After surgical resection the final diagnosis was adenosquamous pancreatic carcinoma(ASPC) arising in an intraductal papillar mucinous neoplasm(IPMN). Adenosquamous carcinomas are uncommon in the pancreas and have rarely been described in association with IPMNs. It has worse prognosis than the ordinary pancreatic ductal adenocarcinoma and some distinct features. We review the clinical, imaging, pathologic and molecular aspects of ASPC. Differential diagnosis with contamination, squamous metaplasia and pancreatic metastases from a distant squamous carcinoma is discussed. Besides, the case is an accelerated model of the adenoma(IPMN)-carcinoma sequence probably due to the CDKN2A ger-mline mutation. Somatic CDKN2A mutations are commonevents in the early steps of sporadic pancreatic cancer, but germline mutation carriers have a significantly higher risk of pancreatic carcinoma.

Esophageal superficial adenosquamous carcinoma resected by endoscopic submucosal dissection:A rare case report

BACKGROUND Adenosquamous carcinoma(ASC),which is comprised of squamous cell carcinoma(SCC)and adenocarcinoma elements,is a rare histological type of esophageal carcinoma.Few reports have focused on the endoscopic findings and the effectiveness of the endoscopic treatment of early ASC.CASE SUMMARY A 77-year-old man underwent esophagogastroduodenoscopy for heartburn.A flat lesion with an uneven and slightly elevated central portion was found in the distal esophagus.Magnifying endoscopy with narrow-band imaging showed a well-demarcated brownish area with dendritically branched abnormal vessels and highly irregular intrapapillary capillary loops.A histopathological diagnosis of SCC was obtained by endoscopic biopsy.Endoscopic ultrasonography revealed a hypoechoic mass confined to the mucosa layer.The lesion was suspected to be SCC with invasion into the muscularis mucosa.The lesion was resected en bloc by endoscopic submucosal dissection and histologically diagnosed as esophageal ASC limited within the muscularis mucosa,which was completely resected without lymphovascular or neural invasion.The SCC element was the predominant element.The adenocarcinoma element formed ductal and nested structures distributed in a focal pattern.The patient underwent only endoscopic submucosal dissection and has been under annual endoscopic and radiographic surveillance for 3 years without recurrence.CONCLUSION For early ASC confined within the mucosal layer,complete endoscopic resection might also be a curative treatment.

Analysis of Gene Expression Profile in Lung Adenosquamous Carcinoma Using cDNA Microarray

Gene expression profile of the lung adenosquamous carcinoma was characterized by using cDNA microarray chip containing 4 096 human genes. Among target genes, 508 differentially expressed genes were identified in adenosquamous carcinoma of the lung, 232 genes were overexpressed and 276 genes were underexpressed. Among them, 92 genes are cell signals transduction genes, 34 genes are proto-oncogenes and tumor suppressor genes or cell cycle related genes or cell apoptosis related genes, 29 genes are cell skeleton genes, 28 genes are DNA synthesis, repair and recombination genes, 12 genes are DNA binding and transcription genes. These genes may be associated with the occurence and development of adenosquamous carinome of the lung. Key words lung carcinoma - adenosquamous carcinoma - microarray - gene expression profile CLC number R 734.2 Foundation item: Supported by the National Natural Science Foundation of China (39870305)Biography: YANG Fei(1972-), female, Ph. D candidate, research direction: etiology and pathogenesis of lung cancer.

Immunotherapy as adjuvant therapy for a patient with adenosquamous carcinoma of the intrahepatic bile duct:A case report and literature review

Adenosquamous carcinoma(ASC)is a rare histological type of intrahepatic cholangiocarcinoma,which includes both adenocarcinoma and squamous cell carcinoma.The clinical features,physical examination,routine laboratory tests,and imaging examinations of patients with ASC are nonspecific.ASC is easily misdiagnosed as hepatocellular carcinoma,and patients with ASC always have a poor prognosis.This study reports a patient with ASC who was diagnosed based on pathological results,underwent surgical resection,and received postoperative chemotherapy(gemcitabine plus cisplatin)combined with immunotherapy(sintilimab).During the 1-year follow-up,the patient was in good condition,and no signs of cancer recurrence were noted.This case highlights that surgical resection and chemotherapy combined with immunotherapy may be feasible for patients with ASC.

Loss of chromosome 9p21 is associated with a poor prognosis in adenosquamous carcinoma of the pancreas

Adenosquamous carcinoma of the pancreas(ASCP)is a rare histological subtype of pancreatic cancer with a poor prognosis and a high metastasis rate.However,little is known about its genomic landscape and prognostic biomarkers.A total of 48 ASCP specimens and 98 pancreatic ductal adenocarcinoma(PDAC)tumour specimens were sequenced to explore the genomic landscape and prognostic biomarkers.The homozygous deletion of the 9p21.3 region(including CDKN2A,CDKN2B,and MTAP)(9p21 loss)occurred in both ASCP and PDAC,and a higher frequency of 9p21 loss was observed in ASCP(12.5%vs 2.0%,P=0.022).Notably,9p21 loss was significantly associated with poor disease-free survival(DFS)in ASCP patients(mDFS(Median DFS)=4.17 vs 7.33 months,HR(Hazard Ratio)=3.70,P=0.009).The most common gene alterations in patients with ASCP were KRAS(96%),TP53(81%),CDKN2A(42%),SMAD4(21%),CDKN2B(13%),and FAT3(13%).The mutation rates of ACVR2A(6.25%vs 0%),FANCA(6.25%vs 0%),RBM10(6.25%vs 0%),and SPTA1(8.33%vs 1.02%)were significantly higher in ASCP than in PDAC.In conclusion,we have comprehensively described the genomic landscape of the largest cohort of ASCP patients to date and highlight that 9p21 loss may be a promising prognostic biomarker for ASCP,which provides a molecular basis for prognosis prediction and new therapeutic strategies for ASCP.

Clinicopathological Characteristics and Prognosis of Patients with Adenosquamous Lung Carcinoma

This study was aimed to characterize clinicopathological features and prognosis of patients with adenosquamous lung carcinoma（ASC）. Among the 2531 patients with lung cancer who underwent surgery between January 2000 and June 2012 in our hospital, 59 were histologically diagnosed as having ASC. The clinicopathological features and follow-up data of ASC patients were collected and analyzed statistically. Superior lobectomy was accomplished in 40 patients, middle and inferior lobectomy in 3, lobectomy plus partial resection of contralateral lung in 5, partial lung resection in 4, and pneumonectomy in 7. Moreover, 22 cases were found to be adenocarcinoma-predominant, and 18 to be squamous cell carcinoma-predominant. The median survival time was 13.6 months, and the 1-, 3-, and 5-year survival rates were 59.9%, 36.4% and 31.2%, respectively. Of the 52 cases with tissue specimens available, 11 had an EGFR mutation（21.2%） and 2 had a KRAS mutation（3.8%）. Multivariate analysis showed that histology subtype, pleural invasion, TNM stage, and postoperative treatment were all independent prognostic factors. The data from the current study demonstrated that SCC-predominant histology represents a better prognosis of ASC. Histology subtype, pleural invasion, TNM stage, and postoperative treatment are independent prognostic factors for ASC and adjuvant therapy may help control the disease.

Adenosquamous Carcinoma of the Larynx: A Case Report and Literature Review

Objective:To retrospectively analyze the clinical characteristics of laryngeal adenosquamous carcinoma(ASC) and review the related literature. Methods: We retrospectively analyzed five male patients with confirmed ASC of the larynx between 2005 and 2010 in our hospital, accounting for 0.2% of the laryngeal malignant tumors in the same period. Results: All patients underwent surgeries including horizontal partial laryngectomy(2 cases), vertical partial laryngectomy(1 case) and total laryngectomy(2 cases). One of the two who underwent total laryngectomy also received post-operative chemoradiotherapy. Four also underwent neck dissections. The mean follow-up time was 77.4±14.98 months. At the end of follow-up, two suffered regional metastasis and another local relapse. They all underwent related operations again and were still alive. The therapeutic approach might follow that of squamous cell carcinoma of the larynx. Conclusion: Our limited cases suggest that the prognosis of adenosquamous carcinoma of the larynx is similar to that of squamous cell carcinoma of the larynx.

ADENOSQUAMOUS LUNG CARCINOMA:CLINICAL CHARACTERISTICS,SURGICAL TREAMENT AND PROGNOSIS

Objective.The effectiveness of surgical resection of adenosquamous carcinoma of the lung remains poorly defined because of the histology’s relatively low frequency, the failure in most published series to separate adenosquamous carcinoma from the other variants of non-small cell lung carcinoma.To define the effectiveness of surgical treatment of adenosquamous carcinoma,we have retrospectively reviewed our hospital experience over a 12-year period. Methods.Retrospectively reviewed 22 cases of adenosquamous carcinoma who were surgically treated,except one patient,in the PUMCH from Jan.1985 to Aug.1997.This series constitutes the 19% of a total of 1 245 patients with all types of surgical treatment for the primary lung cancer during the same time. Results.The adenosquanous carcinoma was mostly presented in the old patients with a mean age of 60 years and mostly located in the peripheral of lung(n=20).The overall 5-year survival was 23%.Those with stage Ⅰ tumors survival was only 18%(n=13), stage Ⅱ 5%. The survival in stage Ⅲ tumors was not longer than 25 months and in stage Ⅳ survival was not longer than 12 months. Conclusion.Our results suggest that adenosquamous carcinoma of lung was a virulent tumor,which exhibited highly aggressive biological behavior with early lymph nodes metastasis(46%) and its prognosis was worse than that of both squamous cell carcinoma and adenocarcinoma.

Hypercalcemia-Leukocytosis syndrome and adenosquamous lung carcinoma:An overlooked conjugation

Hypercalcaemia and leukocytosis are two paraneoplastic conditions associated with poor prognosis.Adenosquamous carcinoma is a rare and aggressive histological subtype of lung cancer consisting of adenocarcinoma and squamous cell components.We report the case of a 57-year-old male smoker who was admitted to the Emergency Room with skull and neck tumefactions,confusion and deteriorated general condition.The complementary study in the ER revealed severe hypercalcaemia(19.8 mg/dL),leukocytosis(18.7×10^(9)/L)and extensive osteolytic lesions of the skull on cranioencephalic computer tomography(CT).The patient was stabilized and admitted.Thoracoabdominopelvic CT showed lung parenchyma consolidation with necrotic areas,supra and infradiaphragmatic adenopathies and scattered osteolytic lesions.Percutaneous lymph node biopsy was consistent with metastasis of adenosquamous lung carcinoma.The patients’clinical situation evolved unfavourably after hospital-acquired infection.This case is characterized by a rare presentation of advanced stage adenosquamous lung carcinoma with scattered osteolytic lesions and severe hypercalcaemia-leukocytosis syndrome,an underrecognized marker of poor prognosis.

Analysis of Prognosis and Prognostic Factors of Cervical Adenocarcinoma and Adenosqumous Carcinoma of the Cervix

OBJECTIVE To analyze clinical characteristics and treatment methods of the patients with adenocarcinoma of the uterine cervix （AUC） and adenosquamous carcinoma of the cervix （ASCC）. To compare the survival time of the patients in 2 groups and analyze the prognostic factors. METHODS Clinical data of both 123 patients with AUC and 32 patients with ASCC treated at the Cancer Hospital, Chinese Academy of Medical Science （CAMS） ＆ Peking Union Medical College （PUMC）, were retrospectively analyzed. RESULTS The median age of the AUC patients was 50 years, and that of the ASCC patients was 44, P = 0.019. Poorly-differentiated （grade 3） cases accounted for 59.5% of the total ASCC patients, while only 32.5% of the AUC patients were in grade 3, P = 0.002. In 123 AUC patients, relapse or failure of the treatment occurred in 63 of the patients （51.2%）, and the median relapse time was 6 months （0-59 months）. In 32 ASCC patients, relapse or failure of the treatment occurred in 8 of these patients （51.2%）, with a median relapse time of 4.5 months （0-52 months）. The overall 5-year survival rate of the AUC patients was 49.8%, which was significantly lower than that of the ASCC patients （74.1%）, P = 0.015. The 5-year survival rates of the ASCC patients in Stage Ⅰ-Ⅲ were higher than that of the AUC patients with the same stages. However, statistical significant difference could only be found among the patients in Stage II, P = 0.006. The 5-year survival rates of the ASCC patients with various differential grade were higher than those of the AUC patients with the same differential grade, but statistical significant difference could only be found among the patients in the two groups with moderately differentiation, P = 0.039. It was found by Cox regression analysis that only clinical stage （P 〈 0.001） and histological type （P = 0.046） were the independent prognostic factors. CONCLUSION Clinical stage and histological type were the independent prognostic factors of the AUC and ASCC patients. The prOgnosis of ASCC patients is better than that of the AUC patients.

Two rare cancers of the exocrine pancreas: to treat or not to treat like ductal adenocarcinoma?

Pancreatic cancer is an aggressive malignancy with increasing incidence.Pancreatic ductal adenocarcinoma(PDAC)accounts for>90%of pancreatic cancer diagnoses,while other exocrine tumors are much rarer.In this review,we have focused on two rare cancers of the exocrine pancreas:adenosquamous carcinoma of the pancreas(ASCP)and pancreatic acinar cell carcinoma(PACC).The latest findings regarding their cellular and molecular pathology,clinical characteristics,prognosis,and clinical management are discussed.New genetic and transcriptomic data suggest that ASCP is related to or overlaps with the basal transcriptomic subtype of PDAC.These tumors are highly aggressive and driven by activated KRAS and MYC expression.Clinical outcomes remain poor and effective treatments are limited.PACC has no morphologic or genetic resemblance to PDAC and more favorable outcomes.Early stage PACC patients have improved survival with surgical resection and patients with advanced disease benefit most from platinum-or fluoropyrimidine-containing chemotherapy.Frequency of actionable genetic mutations is high in this disease and case reports suggest good outcomes when matched therapy is given.Dedicated clinical studies examining ASCP and PACC are limited and difficult to accrue.Further research is needed to define optimal clinical management for these rare diseases.