Intraductal tubular adenomas (pyloric gland-type) of the pancreas: clinicopathologic features are similar to gastric-type intraductal papillary mucinous neoplasms and different from intraductal tubulopapillary neoplasms

Intraductal tubulopapillary neoplasm (ITPN) of the pancreas: a distinct entity among pancreatic tumors

AIMS

Intraductal tubulopapillary neoplasm (ITPN) of the pancreas is a recently recognized pancreatic tumor entity. Here we aimed to determine the most important features with a systematic review coupled with an integrated statistical approach.

METHODS AND RESULTS

PubMed, SCOPUS, and Embase were searched for studies reporting data on pancreatic ITPN. The clinicopathological, immunohistochemical, and molecular data were summarized. Then a comprehensive survival analysis and a comparative analysis of the molecular alterations of ITPN with those of pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasm (IPMN) from reference cohorts (including the International Cancer Genome Consortium- ICGC dataset and The Cancer Genome Atlas, TCGA program) were conducted. The core findings of 128 patients were as follows: (i) Clinicopathological parameters: pancreatic head is the most common site; presence of an associated adenocarcinoma was reported in 60% of cases, but with rare nodal metastasis. (ii) Immunohistochemistry: MUC1 (>90%) and MUC6 (70%) were the most frequently expressed mucins. ITPN lacked the intestinal marker MUC2; unlike IPMN, it did not express MUC5AC. (iii) Molecular landscape: Compared with PDAC/IPMN, the classic pancreatic drivers KRAS, TP53, CDKN2A, SMAD4, GNAS, and RNF43 were less altered in ITPN (P < 0.001), whereas MCL amplifications, FGFR2 fusions, and PI3KCA mutations were commonly altered (P < 0.001). (iv) Survival analysis: ITPN with a "pure" branch duct involvement showed the lowest risk of recurrence.

CONCLUSION

ITPN is a distinct pancreatic neoplasm with specific clinicopathological and molecular characteristics. Its recognition is fundamental for its clinical/prognostic implications and for the enrichment of potential targets for precision oncology.

Pathological features of pyloric gland adenoma of the gallbladder in comparison with gastric subtype of intracholecystic papillary neoplasm

BACKGROUND AND AIMS

Pyloric gland adenoma (PGA) of the gallbladder is a polypoid, preinvasive epithelial neoplasm composed of uniform back-to-back, pyloric glands in a tubular configuration. Intracholecystic papillary neoplasm (ICPN), another preinvasive grossly visible neoplasm of the gallbladder, is subdividable into four subtypes, including gastric subtype. In this study, PGA was reappraised referring to gastric subtype of ICPN (gICPN).

MATERIALS AND METHODS

PGA and gICPN pathologically defined by WHO 2019 classification were surveyed in a total of 104 cases of gallbladder epithelial neoplasms of our Hospital (2002 January to 2021 May) and were pathologically and immunohistochemically compared.

RESULTS

PGA (7 cases) was characterized by i) a well-demarcated, polypoid lesion and ii) packed tubular components resembling pyloric glands. gICPNs (14 cases) were subdivided into i) pyloric gland predominant (2 cases), ii) foveola predominant (6 cases) and iii) mixed foveola and pyloric gland type (6 cases). gICPNs were also divided into a solitary, polypoid lesion with well demarcation from the surrounding mucosa (5 cases) and a conglomerated polypoid and granular lesions with poor demarcation (9 cases). PGA shared gross and histologic features with solitary, polypoid gICPNs, and PGA could be regarded as solitary gICPN predominantly composed of pyloric glands. Nuclear expression of β-catenin was found in 6 of 7 PGA, but absent in gICPN, including solitary, polypoid gICPN.

CONCLUSION

PGA could correspond to a solitary gICPN mainly composed of pyloric glands, but may undergo a different molecular pathway from gICPN.

[Intraductal neoplasms of the pancreas]

The latest WHO classification of tumors of the digestive system (2019) has introduced new concepts for the stratification of intraductal neoplasms of the pancreas, mostly based on molecular genetics and malignant potential. Among them, pancreatic intraepithelial neoplasias (PanINs) and intraductal papillary mucinous neoplasms (IPMN) are both precursors of pancreatic ductal adenocarcinoma, whereas intraductal oncocytic papillary neoplasms (IOPN) and intraductal tubulopapillary neoplasms (ITPN) are usually associated with less aggressive subtypes of pancreatic cancer and therefore have a much better prognosis. Hence, it is of utmost importance to correctly classify these lesions and to distinguish them from each other as well as from other nonductal types of neoplasms, which can rarely display an intraductal growth, such as neuroendocrine tumors and acinar cell carcinomas. PanIN are microscopic lesions with limited clinical significance. In contrast, all other intraductal neoplasms can be identified as cystic processes and/or solid tumors by means of imaging, thereby setting an indication for a potential surgical resection. This review presents diagnostically relevant aspects of intraductal neoplasms of the pancreas, which are instrumental for the discussion within interdisciplinary tumor boards (resection vs. watch-and-wait strategies) as well as to determine the extent of resection intraoperatively.

Intraductal Tubulopapillary Neoplasm: A New Entity in the Spectrum of Pancreatic Intraductal Neoplasms

Intraductal Tubulopapillary Neoplasms (ITPN) is a rare and new entity defined as an intraductal, grossly visible, tubule-forming epithelial neoplasm with high- grade dysplasia and ductal differentiation without overt production of mucin. Its clinical presentation can be varied, which makes the diagnosis quite challenging. In this report, we present a case of pancreatic ITPN and review the published work to learn clinicopathological, radiological features and treatment strategies of this recently proposed pancreatic neoplasm.

Precursors of pancreatic cancer

Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its incidence has been increasing continuously; mortality has not decreased, the diagnosis is frequently late, radical surgery is performed only in 15-20% of patients, and chemotherapy is only palliative. PC occurs in three different forms. Sporadic PC accounts for 90% of all PCs. Its most frequent form is the pancreatic ductal adenocarcinoma. The remaining 10% constitute two minority groups: familial PC (7%) and PC as a manifestation of a genetic cancer syndrome (3%). PCs are preceded by a precancerous lesion (precursor). At present, six different precursors are known. They have different histomorphological characteristics and malignant potential. The recognition and correct interpretation of individual precursors influences adequate clinical decision-making. The publication surveys the present knowledge of individual precursors and their role in the early pancreatic carcinogenesis.

Intraductal papillary mucinous neoplasms of the pancreas: reporting clinically relevant features

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can exhibit a wide spectrum of macroscopic and microscopic appearances. This not only causes occasional difficulties for the reporting pathologist in distinguishing these tumours from other lesions, but is also relevant clinically. As evidence accumulates, it becomes clear that multiple macroscopic and histological features of these neoplasms are relevant to the risk for malignant transformation and, consequently, of prime importance for clinical patient management. The need for detailed reporting is therefore increasing. This review discusses the panoply of gross and microscopic features of IPMN as well as the recommendations from recent consensus meetings regarding the pathology reporting on this tumour entity.

Pathology of Pancreatic Cancer Precursor Lesions

To better understand pancreatic ductal adenocarcinoma (PDAC) and improve its prognosis, it is essential to understand its origins. This article describes the pathology of the 3 well-established pancreatic cancer precursor lesions: pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. Each of these precursor lesions has unique clinical findings, gross and microscopic features, and molecular aberrations. This article focuses on histopathologic diagnostic criteria and reporting guidelines. The genetics of these lesions are briefly discussed. Early detection and adequate treatment of pancreatic cancer precursor lesions has the potential to prevent pancreatic cancer and improve the prognosis of PDAC.

KRAS, GNAS, and RNF43 mutations in intraductal papillary mucinous neoplasm of the pancreas: a meta-analysis

Background

The prevalence and clinical significances of KRAS, GNAS, and RNF43 mutations in patients with pancreatic intraductal papillary mucinous neoplasm (IPMN) remain elusive. To evaluate the incidence of the gene mutations and clinicopathologic differences between KRAS and GNAS mutations in pancreatic cystic lesions, we performed a meta-analysis of published 33 KRAS, 11 GNAS, and 4 RNF43 studies including 1253, 835, and 143 cases, respectively.

Methods

We pooled the results of relevant studies identified using the PubMed and EMBASE databases. The effect sizes of outcome parameters were computed by the prevalence rate, weighted mean difference, or odds ratio (OR) using a random-effects model.

Results

The pooled prevalence of KRAS, GNAS, and RNF43 mutations in IPMN was 61, 56, and 23 %, respectively. The KRAS (OR 7.4 and 71.2) and GNAS (OR 30.2 and 15.3) mutations were more frequently found in IPMNs than in mucinous cystic neoplasms and in serous cystadenomas, respectively. Of the microscopic subtypes of IPMN, KRAS and GNAS were frequently mutated in gastric type (OR 2.7, P < 0.001) and intestinal type (OR 3.0, P < 0.001), respectively. KRAS mutation was infrequently found in high-grade dysplasia lesions of IPMN (OR 0.6, P = 0.032). GNAS mutation was associated with male (OR 1.9, P = 0.012).

Conclusions

This meta-analysis supports that KRAS and GNAS mutations could be diagnostic markers for IPMN. In addition, the frequencies of KRAS and GNAS mutations in IPMNs are highly variable according to the microscopic duct subtypes, reflecting their independent roles in the IPMN-adenocarcinoma sequence.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2847-4) contains supplementary material, which is available to authorized users.

Clinicopathological features and surgical outcomes of intraductal tubulopapillary neoplasm of the pancreas: a systematic review

BACKGROUND AND AIMS

Intraductal tubulopapillary neoplasms (ITPNs) of the pancreas are rare. The purpose of this study was to collate and analyze published data on ITPNs of the pancreas to determine the clinicopathological features of the tumors and the surgical outcomes of patients.

PATIENTS AND METHODS

We searched MEDLINE and Igakuchuo-Zasshi for the period of 1980 to 2015 for case reports on surgical resection for ITPN of the pancreas. We evaluated the clinicopathological data associated with pancreatic ITPNs, the prognosis for each patient, and surgical outcomes described in the case reports.

RESULTS

We obtained clinicopathological data for 58 patients (33 men and 25 women) with a mean age of 61 years (range, 35-84 years) who had undergone surgical resection for ITPN of the pancreas, including one patient from our clinic. Although ITPNs of the pancreas have different clinicopathological features to intraductal papillary mucinous neoplasms, the treatment strategy for patients with ITPNs is the same as for patients with other cystic neoplasms of the pancreas. The immunohistochemical features of ITPNs included testing positive for cytokeratin 7 and/or cytokeratin 19 and negative for trypsin, MUC2, MUC5AC, and fascin. The overall 1-, 3-, and 5-year survival rates after surgery for the 37 cases with available data were 97.3, 80.7, and 80.7 %, respectively.

CONCLUSION

Surgical treatment is the only curative management option for patients with ITPN of the pancreas. To determine the best management strategy for this tumor and improve accuracy of prognosis for patients, we will continue to collect and analyze epidemiological and pathological data.

Multifocal intraductal tubulopapillary neoplasm of the pancreas with total pancreatectomy: report of a case and review of literature

Intraductal neoplasms of the pancreas are classified as intraductal tubulopapillary neoplasms (ITPNs) and intraductal papillary mucinous neoplasm (IPMNs) in the current WHO classification. ITPN is a rare tumor and there are only a few cases of ITPN reported in the literature. We present the case of an otherwise healthy 42-year-old male, who presented with upper abdominal pain. He was subsequently diagnosed with multifocal ITPN and underwent total pancreatectomy. The pathological report showed invasive growth. The postoperative course was uneventful and the patient received 6 months of adjuvant chemotherapy with gemcitabine-capecitabine. The patient is still alive 19 months after the procedure with no signs of recurrence. Literature review revealed only 30 individual cases of ITPN in the pancreas including our reported case. Mean age was 61 years (16 males/14 females; ratio 1.14:1). Mean tumor size was 3 cm. Immunohistochemical staining was positive for CK-7 in 100% of the patients, CK-19 in 95% and for MUC-1 in 88%. Trypsin was negative in all cases. β-catenin was negative in 94% and MUC-2 was negative in 96% of the cases. BRAF, KRAS, TP53 and PIK3CA mutations were infrequently seen. Invasive growth was present in 54% of the cases. Tumor size and Ki-67 index showed a statistically significant association with invasive growth. Survival rate could not be determined, due to short follow-up, and further research is needed to establish prognostic factors for disease recurrence and survival.