Adenocarcinoma in Intraductal Tubulopapillary Neoplasm of the Pancreas: A Case Report and Literature Review.

Intraductal tubulopapillary neoplasms (ITPNs) are a subgroup of pre-malignant pancreatic epithelial lesions. The histomorphological and immunophenotypical characteristics of ITPN have been described by several authors based on case series; however, the rarity of this tumor subtype and its similarity to other entities makes the identification of ITPN challenging for radiologists and pathologists. Herein, we report a case of ITPN with associated invasive carcinoma along with a literature review that will benefit further studies and help in planning treatments for patients in the future. A pancreatic mass was incidentally discovered in a 40-year-old woman during her annual check-up. Radiological investigation revealed a mass that obstructed the main pancreatic duct and caused ductal dilatation. Endoscopic retrograde cholangiopancreatography with biopsy indicated poorly differentiated adenocarcinoma. Subsequently, total pancreatectomy with splenectomy was performed to remove the tumor. ITPN of the pancreas with associated poorly differentiated adenocarcinoma was diagnosed based on pathological and immunohistological test results. Achieving complete resection of the tumor, the patient did not require chemotherapy during follow-up care. Thus, our study demonstrated the necessity of radiological and histopathological correlation in the definitive diagnosis of pancreatic ITPN. However, the determination of an invasive component is essential because malignant transformation affects the prognosis of patients.

Intraductal neoplasms of the pancreatobiliary tract: navigating the alphabet.

Cancers of the pancreatobiliary tract are diseases with unfavourable prognoses. In the last couple of decades, two types of lesions have been described as precursors that precede pancreatobiliary cancers. These include incidental microscopic (flat) lesions known as pancreatic intra-epithelial neoplasia and biliary intra-epithelial neoplasia, and grossly visible, mass-forming lesions (tumoral intra-epithelial neoplasia) including intraductal papillary mucinous neoplasms, intraductal oncocytic papillary neoplasms, intraductal tubulopapillary neoplasms, intraductal papillary neoplasms of the bile duct and intracholecystic papillary neoplasms. Early detection and adequate treatment of these precursor lesions, especially the second group, have the potential to prevent pancreatobiliary cancer or at least improve its prognosis. In this review, we discuss their histopathology and recent updates on molecular profiling of these intraductal neoplasms of the pancreatobiliary tract.

Intraductal Tubulopapillary Neoplasm Diagnosed Before Surgery: A Case Report.

Intraductal tubulopapillary neoplasm (ITPN) is a rare disease in the pancreas with a better prognosis than pancreatic ductal adenocarcinoma (PDAC) and a different treatment strategy. Therefore, it is important to confirm its diagnosis before the surgery. However, few cases have been diagnosed preoperatively. In this report, we present a case of ITPN that was successfully diagnosed preoperatively. A 70-year-old female patient was incidentally diagnosed with a pancreatic tumor. The patient was asymptomatic, and her blood tests were all within the normal range. A dynamic computed tomography scan showed an indistinct mass with small cysts and a dilated pancreatic duct. The mass was well contrasted in the arterial phase. These findings were not enough to confirm ITPN. Therefore, endoscopic ultrasonography fine needle aspiration biopsy was performed. The specimen had no mucin and the neoplastic cells exhibited a tubulopapillary growth pattern. Moreover, the neoplastic cells were immunohistochemically positive for MUC1, CK7, and CK20, but negative for MUC2, MUC5AC, synaptophysin, and Bcl-10. Consequently, the preoperative diagnosis was confirmed as ITPN. Hence, a subtotal-stomach-preserving pancreaticoduodenectomy was performed, and the patient had a good postoperative course and was discharged after 26 days. Tegafur, gimeracil, and oteracil were administered as postoperative adjuvant chemotherapies for one year. Seventeen months after the surgery, no recurrence has been detected. ITPN and PDAC have different prognoses and treatment strategies. In this report, we experienced a case of ITPN preoperatively diagnosed and successfully treated.

Intraductal tubulopapillary neoplasms of the bile ducts: identity, clinicopathologic characteristics, and differential diagnosis of a distinct entity among intraductal tumors.

Among the mass-forming preinvasive (tumoral intraepithelial) neoplasms of the biliary tract, intraductal tubulopapillary neoplasms (ITPN-Bs) are increasingly being recognized as a separate category. By being intramucosal polypoid proliferations of dysplastic/neoplastic cells, they are highly similar to other members of the "intraductal neoplasms (IDNs)" category (namely, intraductal papillary neoplasms [IPNBs], and intraductal oncocytic papillary neoplasms [IOPNs]); however, they are distinguished by MUC6-expressing nonmucinous cells that lack intestinal differentiation and form striking tubular configuration. Their molecular/genetic profile is also proving to be different with frequent alterations in cell cycle and chromatin remodeling genes, which are quite uncommon in other IDNs and cholangiocarcinomas. Despite the conceptual overlaps, they are also very different from intracholecystic nonmucinous tubular neoplasms (ICTN) of the gallbladder with the latter being associated with Wnt/beta-catenin pathway alterations, and almost never invasive. In contrast, ITPN-Bs are invasive in an estimated 80% of the cases, although even invasive examples often exhibit a protracted course. Invasive carcinomas arising from ITPN-Bs are overall similar to cholangiocarcinomas (including small duct and large duct patterns) but also often have peculiar characteristics such as more nodular-compact (blunt invasion) pattern. Like other IDNs, the ITPN-Bs have also been classified in the past as intraductal-spreading type of cholangiocarcinomas (and they are still regarded as such in some publications). In small biopsies, they are prone to be mistaken as ordinary adenocarcinomas because of their tubular pattern and pancreatobiliary cytology although their relatively monotonous cytology and zones of back-to-back tubule formation can help in their correct identification. Clinical presentation of ITPN-Bs is generally similar to other intraductal neoplasms; however, in the intrahepatic component, they tend to be more nodular than cystic, and their snake-like intraductal growth pattern is often more striking. In the management (diagnosis and treatment) of these tumors that are in essence adenoma-carcinoma sequence, the invasive and noninvasive components ought to be evaluated separately. Minimally invasive examples are commonly curable, and even those more extensively invasive may have a surprisingly good prognosis. In summary, biliary ITPNs form a distinct category not only clinicopathologically, immunophenotypically, and molecular-wise but regarding their biological behavior as well.

Clinical and pathological features of intraductal tubulopapillary neoplasms / 中华肝胆外科杂志

Objective:To investigate the clinical and pathological features and improve the acknowledgement of intraductal tubulopapillary neoplasm (ITPN) of pancreas.Methods:Six cases with ITPN in the Shandong Provincial Hospital Affiliated to Shandong First Medical University combined with 40 cases from PubMed and CNKI were retrospectively analyzed. There were 25 males and 21 females, aged (58.6±16.0) years. The clinical manifestations, pathological features, treatment and so on were analyzed.Results:All cases were treated with surgery. The main clinical symptoms were upper abdominal pain and discomfort (23 cases, 50.0%), followed by jaundice (9 cases, 19.6%). Seven cases (15.2%) had no clinical symptoms. Three cases (6.5%) had low back discomfort, chills and other rare symptoms, and 4 cases (8.7%) had no clinical symptoms mentioned in the literature. Tumors of 27 cases (58.7%) located in the head of the pancreas, 9 cases (19.6%) in the body and tail, 4 cases (8.7%) in the whole pancreas, 3 cases (6.5%) in the body, 2 cases (4.3%) in ampulla and 1 case (2.2%) in head and body. Most of the tumors located in the main pancreatic duct. Microscopically, back-to-back tubular glands were densely arranged, parts of them with papillary structure, with obvious cell atypia and many mitoses. Twenty-two cases (47.8%) of ITPN were completely confined to the pancreatic duct, and 24 cases (52.2%) were with associated invasive carcinoma. Tumor cells were positive for cytokeratin 7 and mucin 1, but negative for cytokeratin 20, synaptophysin, chromogranin and trypsin. Mucin 2, mucin 5AC and mucin 6 were negative in most cases. Ki-67 ranged from 10% to 70%.Conclusion:Pancreatic ITPNs were mostly located in the pancreatic head, confined to the main pancreatic duct, and were mostly manifested as pain and discomfort in the upper abdomen. Surgery was the main treatment. Tumors cells of ITPN were arranged in tubular and papillary, with severe epithelial atypia and special immunophenotype, parts of cases accompanied with associated invasive carcinoma.

Rapid transformation of branched pancreatic duct-derived intraductal tubulopapillary neoplasm into an invasive carcinoma: A case report.

BACKGROUND: Intraductal tubulopapillary neoplasm (ITPN) is a rare disease accounting for approximately 3% of all intraductal pancreatic tumors, with intraductal papillary mucinous neoplasm (IPMN) being one of the most common differential diagnoses. Both ITPN and IPMN display slow growth. A branched pancreatic duct type is commonly observed in IPMN, whereas ITPN derived from the branched pancreatic duct has been reported in a limited number of cases; hence, its pathogenesis remains unclear. CASE SUMMARY: Here, we present the case of a patient with ITPN localized in a branched pancreatic duct, with poorly controlled irritable bowel syndrome. A contrast-enhanced computed tomography scan of the abdomen incidentally revealed a 5-mm oligemic nodule-like change in the body of the pancreas. Endoscopic ultrasound (EUS) indicated a 10-mm hypoechoic mass without any cystic structures that had grown within 2 mo. EUS-guided fine needle aspiration was performed for definitive diagnosis, and the findings suggested ductal papillary carcinoma. Distal pancreatectomy was performed, and the tumor was pathologically diagnosed as ITPN with an invasive cancerous component, pT3N1aM0, pStage IIB (International Cancer Control, 8th edition). The patient underwent treatment with postoperative adjuvant chemotherapy (S-1 monotherapy); however, relapse was observed 1 year and 10 mo after surgical resection, and subsequent treatment involving a combination of chemotherapy and radiotherapy was administered. Maintenance therapy has since facilitated a stable disease state. CONCLUSION: Regardless of the microscopic size of the neoplasm, early diagnosis of ITPN with EUS-guided fine needle aspiration and surgical resection are crucial.

Corrigendum: Updates in the Diagnosis of Intraductal Neoplasms of the Pancreas.

[This corrects the article DOI: 10.3389/fphys.2022.856803.].

Updates in the Diagnosis of Intraductal Neoplasms of the Pancreas.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest types of cancer worldwide. There are many reasons for this dismal prognosis, including the advanced stage at the time of diagnosis and the lack of effective therapeutic approaches. Intraductal papillary mucinous neoplasms (IPMNs) represent detectable and treatable precursor lesions of PDAC. Our understanding of the pathology of IPMNs has evolved over the past few decades, and new advances in diagnostic tools have emerged. The new World Health Organization (WHO) classification scheme now recognizes the previously considered variants of IPMNs, such as intraductal oncocytic papillary neoplasms (IOPNs) and intraductal tubulopapillary neoplasms (ITPNs), as distinct neoplasms. New imaging and molecular diagnostic tests are being developed to recognize these PDAC precursor lesions better. Here, we review the advances in diagnostic tools for IPMNs, IOPNs, and ITPNs, emphasizing the new (5th edition, 2019) WHO classification for pathological diagnosis, molecular markers, new laboratory tests, and imaging tools.

Systematic review of resectable intraductal tubulopapillary neoplasm with special reference to recurrence patterns.

PURPOSE: Intraductal tubulopapillary neoplasm is a rare pancreatic tumor. The purpose of this study was to clarify the recurrence type and prognosis in recurrent cases after intraductal tubulopapillary neoplasm resection. METHODS: PubMed was searched for previous reports on surgical resection of intraductal tubulopapillary neoplasm of the pancreas that were published from 2009 to July 2020. The clinical features obtained from these reports were summarized and analyzed. RESULTS: The clinicopathological data of 35 intraductal tubulopapillary neoplasm cases were obtained. Of these, 21 were males, and 14 were females, with an average age of 57.9 years old. Invasive findings were observed in 21 of 35 patients (60%). Recurrence was observed in 11 of the 35 cases (31.4%), including remnant pancreatic recurrence in 6 cases (17.1%) and liver metastasis in 5 cases (14.3%). The tumor size was significantly larger in the liver metastasis group than in the remnant pancreas recurrence group (P = 0.04), and patients with liver metastases tended to have a poorer prognosis than those with remnant pancreas recurrence. CONCLUSIONS: The recurrence type of intraductal tubulopapillary neoplasm resection was mainly remnant pancreatic recurrence and liver metastasis recurrence. Total pancreatectomy for remnant pancreatic recurrence may be suitable because of its good prognosis.

A case of intraductal tubulopapillary neoplasm of the pancreas originating from the branch duct: cast in the mold sign.

A 59-year-old man with jaundice and lower common bile duct stenosis was referred to our institution for diagnosis and treatment. Computed tomography and magnetic resonance imaging showed a well-circumscribed smoothly marginated solid mass lesion in the pancreatic head. He underwent pyloric preserving pancreatoduodenectomy. Histopathological specimen revealed that the mass was located in the dilated branch duct of the pancreatic head, and an intraductal tubulopapillary neoplasm originating from the branch pancreatic duct was diagnosed. On magnetic resonance cholangiopancreatography, the mass within the dilated duct branch in the pancreatic head was similar to a "cast in the mold" image, which we retrospectively deemed, might be reflecting the nature of this tumor.

Pathology of intraductal papillary mucinous neoplasms.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) represent a unique opportunity to treat and prevent a curable neoplasm before it has the chance to progress to incurable cancer. This prospect, however, has to be balanced with the real risk of over treating patients with lesions that would, in fact, never progress during the life of the patient. PURPOSE: Informed clinical decisions in the treatment of IPMNs are first and foremost based on a deep understanding of the pathology of these lesions. CONCLUSIONS: Here we review the pathology of IPMNs, with an emphasis on the clinical relevance of the important features that characterize these lesions.

A case of intraductal tubulopapillary neoplasm of the pancreas in a branch duct: a rare case report and literature review.

BACKGROUND: Intraductal tubulopapillary neoplasm (ITPN) of the pancreas is a new disease concept defined by the World Health Organization in 2010. ITPN progresses with tubulopapillary growth in the pancreatic duct and is known to have a fair prognosis. Localization in the main pancreatic duct (MPD) is one characteristic. There are few case reports of ITPN in a branch of the pancreatic duct (BD). CASE PRESENTATION: We encountered a case of ITPN localized in BD. An 85-year-old man was followed after colonic surgery for rectal carcinoma. An abdominal computed tomography scan revealed a cystic mass in the pancreatic head and further examination was done. A T2 weighted intension picture in magnetic resonance imaging showed a 20 mm cystic lesion with an internal mass of 15 mm. Duodenal papilla were slightly open and endoscopic retrograde pancreatography revealed mild and diffuse dilatation of the main pancreatic duct and mucin in the MPD. In consideration with the image examinations, we diagnosed the tumor as an intraductal papillary mucinous neoplasm with carcinoma because of its large mural nodule (> 10 mm in size) in a cyst. Consequently, a pancreaticoduodenectomy was performed. Macroscopically, a white solid tumor sized 2.5 × 1.8 × 1.0 was identified in the head of the pancreas. The cut surface of the resected pancreas showed a side-branch type intraductal tumor with tubulopapillary architecture without mucin secretion. Immunohistochemical staining was positive for MUC1, and negative for MUC2 and MUC5AC. The final diagnosis was determined to be pancreatic ITPN from BD. At the time of this report (48 months post-surgery), the patient remains disease-free without evidence of recurrence. CONCLUSION: ITPNs localized in BD are rare and diagnosis prior to surgery is difficult. In our case, the shape was round, not papillary, and with little fluid. These characteristics are different from a branch duct type IPMN and can be a clue to suspect ITPN in BD.

Pancreatic intraductal tubulopapillary neoplasm progression requiring completion pancreatectomy: A case report and literature review.

INTRODUCTION: Intraductal tubulopapillary neoplasm (ITPN) is a recently described rare tumor of the pancreas. Diagnostic approach and treatment are based on relatively few cases. PRESENTATION OF CASE: Here we report a case of a 68-year-old male presenting with an ampullary adenoma with high grade dysplasia who underwent pancreaticoduodenectomy and was incidentally found to have an ITPN at the pancreatic resection margin with areas of microinvasion throughout the resected specimen. He went on to rapidly develop an invasive adenocarcinoma arising in association with recurrent ITPN in the remnant pancreas requiring a completion total pancreatectomy. DISCUSSION: Patients with ITPN present with non-specific symptoms and diagnosis can be challenging. Radiographic evaluation will reveal tumor ingrowth into the main pancreatic duct and distal duct dilatation without upstream dilation or mucinous engorgement. ITPNs are treated with formal resection given that determination of an invasive component can be difficult and the risk of malignant transformation. Following resection, recurrences are infrequent and 5-year survival is over 70 % even with microinvasion. CONCLUSIONS: ITPNs can follow a variable clinical course but hold the potential for malignant transformation. When ITPN is incidentally found at a pancreatic resection margin, we recommend completion resection due to the risk of local recurrence.

Intraductal tubulopapillary neoplasms with rupture of the distal main pancreatic duct: a case report.

BACKGROUND: Intraductal tubulopapillary neoplasm (ITPN) is a rare and newly described entity defined as an intraductal, grossly visible, tubule-forming epithelial neoplasm with high-grade dysplasia and ductal differentiation without overt production of mucin. Because of its rarity, the clinical and molecular aspects of ITPN have not been fully investigated. CASE PRESENTATION: A 73-year-old woman presented to a local hospital with epigastric discomfort and pain. Abdominal multidetector-row computed tomography (MDCT) revealed a 2.5-cm hypovascular tumor in the pancreatic body with distal pancreatic duct dilatation and a slightly low-density area spreading over the ventral side of the pancreatic body. Endoscopic ultrasonography and fine-needle biopsy of the tumor revealed adenocarcinoma of the pancreas. She was referred to our hospital 2 months later. MDCT performed at our hospital showed no significant change in the tumor size or pancreatic duct dilatation. However, the low-density area at the ventral side of the pancreas had shrunk; therefore, this finding was considered to have been an inflammatory change. Under a preoperative diagnosis of resectable pancreatic ductal adenocarcinoma, distal pancreatectomy was performed. The final diagnosis was ITPN with associated invasive carcinoma. Macroscopically and microscopically, the main pancreatic duct (MPD) had ruptured at the distal side of the tumor, and the fistula connected the MPD and extrapancreatic scar tissue. CONCLUSIONS: ITPN with rupture of the pancreatic duct is extremely rare. In the present case, a sudden increase in the pancreatic duct internal pressure or acute inflammation likely caused the rupture of the MPD.

A resected case of recurrent ITPN in the remnant pancreas after pancreatoduodenectomy.

BACKGROUND: Since intraductal tubulopapillary neoplasm (ITPN) is a rare disease, the clinical features of ITPN, especially the characteristics related to recurrence, have not been revealed. We performed a total remnant pancreatectomy for a patient whose ITPN recurred 16 months after pancreatoduodenectomy (PD). We report useful findings to clarify how ITPN reoccurs based on this experience and previously reported cases. CASE PRESENTATION: A 61-year-old male patient was diagnosed with pancreatic cancer and underwent PD. However, a postoperative pathologic examination diagnosed ITPN with invasive cancer. After receiving adjuvant chemotherapy, he was hospitalized for pancreatitis 16 months after the operation. He was diagnosed as having recurrence near the pancreato-jejunal anastomosis based on detailed examinations and underwent a remnant total pancreatectomy. From the results of the histopathological examination, he was found to have a recurrence of ITPN as a polypoid mass without invasion distant from the surgical stump of the first operation. Furthermore, tumor cells floating in the main pancreatic duct distant from the main tumor were observed at three locations. REVIEW OF THE LITERATURE: Including our case, five cases of recurrence in the remnant pancreas after surgery for ITPN have been reported. Recurrence in the main pancreatic duct was observed in four of these five cases. The primary tumor, which recurred in the remnant pancreas after surgery, was characterized as being relatively small and less invasive; however, Ki-67 labeling index was high. In immunohistochemical examination, the expression of MUC6, which is not one of characteristics of ITPN, tended to be positive. CONCLUSION: In this case, tumor cells were floating inside the pancreatic duct at several locations. From the results of this case and a review of previous reports, the cause of ITPN recurrence in this case seemed to be due to tumor cells leaving the tumor and implanting into the pancreatic duct.

Intraductal tubulopapillary neoplasm (ITPN) of the pancreas with invasive cancer misdiagnosed as a mesenteric cyst for 12 years: a case report and literature review.

INTRODUCTION: An intraductal tubulopapillary neoplasm (ITPN) depicts a distinct entity in the subgroup of premalignant epithelial tumors of the pancreas. Due to the rarity of ITPN, information regarding the disease is currently limited. We present herein a case of pancreatic ITPN with invasive cancer that was misdiagnosed as a mesenteric cyst during a 12-year follow-up period. CASE REPORT: A 23-year-old female initially presented with an incidental asymptomatic 4-cm retroperitoneal cystic lesion in 2005. For 12 years of surveillance, the lesion remained largely unchanged in size (4-5 cm). In 2017, the cystic lesion was found to have grown to 9 cm. The pre-operative diagnosis was highly suggestive of a benign lesion. However, after total resection of the mass was performed, the final diagnosis was pancreatic ITPN with invasive cancer. The patient recovered uneventfully and is disease-free without recurrence at the time of this report (12 months post-surgery). CONCLUSION: The clinicopathologic features of ITPN remain unclear due to its rarity, thus making diagnosis difficult. Clinicians should always consider the possibility of ITPN for cystic lesions located at the retroperitoneum near the tail of the pancreas. More data are needed to understand the disease's long-term outcome to identify clinical and radiological features that can be useful for its diagnosis.

An extremely rare case who underwent total remnant pancreatectomy due to recurrent pancreatic metastasis of intraductal tubulopapillary neoplasm.

We describe a rare case of recurrent pancreatic metastasis of intraductal tubulopapillary neoplasm (ITPN). A 53-year-old woman diagnosed with an intraductal papillary mucinous neoplasm (IPMN) and a pancreatic ductal adenocarcinoma (PDAC) of the pancreatic body underwent a distal pancreatectomy. The tumor was composed of cuboidal, high-grade dysplastic cells proliferating in a tubulopapillary growth pattern without mucin production; hence, the final diagnosis was ITPN. A follow-up computed tomography scan revealed an enhanced 2 cm mass of the pancreatic head 3 years after the surgery. From workup investigations, the patient was diagnosed with PDAC or a recurrent ITPN of the remnant pancreas. A total remnant pancreatectomy was then performed. Histopathological findings revealed that the new ITPN had the same features as the prior ITPN. In IPMNs, the presence of an invasive component and high-grade dysplasia can lead to progression to a recurring IPMN and the development of PDAC. Because there have been few reports of recurrent ITPN developing into PDAC, the risk factors for ITPN have not been investigated. Because of the uncertain clinicopathological characteristics of ITPN, more data should be gathered to assess the long-term outcome and malignant potential of ITPN.

Precursor Lesions of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer death. Although the treatment modalities are improving, the prognosis of PDAC continues to be poor. Therefore, early detection of PDAC or its precursor lesions may be the best way to improve patient survival. PDACs have several different precursor lesions, including pancreatic intraepithelial neoplasias (PanINs), intraductal papillary mucinous neoplasms (IPMNs), intraductal tubulopapillary neoplasms (ITPNs), intraductal oncocytic papillary neoplasms (IOPNs), and mucinous cystic neoplasms (MCNs). PanINs cannot be identified using imaging modalities, while the other lesions are radiologically detectable. These precursor lesions are categorized based on structural and cytological atypia as low-grade and high-grade lesions. We discuss recent updates regarding histopathological and molecular pathological overviews of PDAC precursor lesions. Better understanding of such lesions may contribute to earlier detection of PDAC or its precursor lesions and improve PDAC patient survival.

Histo-molecular oncogenesis of pancreatic cancer: From precancerous lesions to invasive ductal adenocarcinoma.

Pancreatic cancer is a lethal malignancy, whose precursor lesions are pancreatic intraepithelial neoplasm, intraductal papillary mucinous neoplasm, intraductal tubulopapillary neoplasm, and mucinous cystic neoplasm. To better understand the biology of pancreatic cancer, it is fundamental to know its precursors and to study the mechanisms of carcinogenesis. Each of these precursors displays peculiar histological features, as well as specific molecular alterations. Starting from such pre-invasive lesions, this review aims at summarizing the most important aspects of carcinogenesis of pancreatic cancer, with a specific focus on the recent advances and the future perspectives of the research on this lethal tumor type.

Intrapancreatic recurrence of intraductal tubulopapillary neoplasm (ITPN) 16 years after the initial surgery for noninvasive ITPN: a case report.

BACKGROUND: Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic intraductal neoplasm. It is characterized by a tubulopapillary growth pattern, entirely high-grade atypical cells, minimal cytoplasmic mucin, and no obvious luminal mucin secretion. Most of its biological nature remains unclear. CASE PRESENTATION: We herein report a case of intrapancreatic recurrence of ITPN in the remnant pancreas of a patient who underwent pancreatoduodenectomy 16 years previously for a noninvasive intraductal pancreatic head tumor. We reexamined the primary tumor and compared it with the most recently resected specimen. Histologically, the primary tumor showed a tubulopapillary growth of high-grade atypical cells with scanty cytoplasmic mucin, which was similar to the recently resected specimen except for the invasive area. Immunohistochemically, the neoplastic cells in both specimens showed focal staining of MUC1 and positivity for MUC6 but negativity for MUC2, MUC5AC, CDX2, and trypsin. Molecular analysis revealed no KRAS/GNAS/BRAF/PIK3CA mutations in either of the specimens. CONCLUSIONS: These findings of the original tumor and recently resected tumor were compatible with the features of ITPN. Thus, recurrence is possible even for a primary noninvasive ITPN, and long-term surveillance is recommended.