A pancreatic mucinous cystic neoplasm undergoing intriguing morphological changes over time and associated with recurrent pancreatitis: A case report

Mucinous cystadenoma of the pancreas associated with pancreatic pseudocyst

Mucinous cystadenoma of the pancreas is considered as a premalignant lesion, and resection is recommended. The majority of pancreatic cystic lesions are pancreatic pseudocysts, so differentiation between mucinous cystadenoma and pseudocyst is frequently required. We report a rare case of mucinous cystadenoma of the pancreas coexisting with pseudocyst. A 43-year-old woman presented with abdominal pain. Imaging examinations showed a large cystic lesion in the tail of the pancreas, and distal pancreatectomy and splenectomy were performed. Pathological examination revealed that the majority of the cystic wall comprised thick collagen fibrous connective tissue, while part of the cystic wall represented a single layer of columnar, mucin-producing epithelium without atypia. Those findings suggested mucinous cystadenoma with an inflammatory pseudocyst. The mixture of mucinous cystadenoma and pseudocyst within the same cystic lesion appears to be very rare. Complete resection of the cystic lesion seems to allow an excellent prognosis.

Clinical and Molecular Attributes and Evaluation of Pancreatic Cystic Neoplasm

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are all considered "Pancreatic cystic neoplasms (PCNs)" and show a varying risk of developing into pancreatic ductal adenocarcinoma (PDAC). These lesions display different molecular characteristics, mutations, and clinical manifestations. A lack of detailed understanding of PCN subtype characteristics and their molecular mechanisms limits the development of efficient diagnostic tools and therapeutic strategies for these lesions. Proper in vivo mouse models that mimic human PCNs are also needed to study the molecular mechanisms and for therapeutic testing. A comprehensive understanding of the current status of PCN biology, mechanisms, current diagnostic methods, and therapies will help in the early detection and proper management of patients with these lesions and PDAC. This review aims to describe all these aspects of PCNs, specifically IPMNs, by describing the future perspectives.

Can regular follow-up imaging contribute to the determination of appropriate timing of surgery in patients with undiagnosed mucinous cystic neoplasm? A multicenter retrospective study

OBJECTIVE

Guidelines suggest that patients with undiagnosed pancreatic cystic lesions should be monitored despite a lack of evidence supporting surveillance for undiagnosed mucinous cystic neoplasms (MCNs). We aimed to investigate the pre- and post-operative clinical course of patients with MCN and the utility of follow-up for patients who were not diagnosed with MCN at initial examination.

PATIENTS AND METHODS

This multicenter retrospective study enrolled 28 patients with resected pathology-proven MCN; 12 and 16 patients underwent surgery within and after 6 months from the initial examination (Groups A and B, respectively). Outcome measures included changes in imaging findings until surgery in Group B, pathological findings between both groups and differences in pathological findings between patients with and without regular follow-up imaging in Group B.

RESULTS

In Group B, the median cyst size was 30 and 48 mm at the initial examination and immediately before surgery, respectively. The incidence of mural cysts, thickened walls and mural nodules were 25, 19 and 0%, respectively, at the initial examination and 69, 56 and 31%, respectively, immediately before surgery. There were no significant differences in the invasive carcinoma rates between Groups A and B (13 vs. 17%). Regular follow-up imaging was offered to Group B. Among these, invasive carcinoma was found in one patient exhibiting no recurrence. One patient without follow-up imaging had invasive carcinoma recurrence post-operatively.

CONCLUSIONS

MCNs increased in size, and typical imaging findings appeared over time. For undiagnosed MCN, regular follow-up examination contributed to the determination of the appropriate surgical timing.

A narrative review of a type of pancreatitis worthy of attention: acute pancreatitis associated with pancreatic tumors-current problems and future thinking

OBJECTIVE

Our purpose is to explain the onset, diagnosis, and treatment of pancreatic tumor-associated pancreatitis (PTP), and inform clinicians about the management of PTP. It is hoped that clinicians can gain some experience and inspiration from this review, so that patients can obtain better treatment results.

BACKGROUND

Acute pancreatitis (AP) is an inflammatory disease, and pancreatic tumors are one of the causes of pancreatitis. When pancreatic tumors and pancreatitis exist at the same time, and there is a "connection" between them, this type of pancreatitis is referred to as PTP. The manifestations of PTP can be as follows: (I) AP is the first symptom of pancreatic tumors; (II) pancreatitis is found in patients after pancreatic tumor diagnosis or during pancreatic tumor surgery. Because pancreatic tumors are not one of the most common causes of pancreatitis, PTP has not attracted the attention of researchers and clinicians, and there is no consistent and clear understanding of the diagnosis and treatment of PTP.

METHODS

From the online database PubMed (https://pubmed.ncbi.nlm.nih.gov/) and Web of Science (https://webofknowledge.com/), we use specific retrieval strategies to retrieve relevant articles, and we review and discuss them.

CONCLUSIONS

What we need to realize is that PTP is different from ordinary AP. It has its own characteristics in terms of diagnosis and treatment, which requires the attention of clinicians. More importantly, future research should design the best diagnosis and treatment algorithms for PTP.

Mucinous cystic adenoma with inflammatory cell infiltration around the splenic artery mimicking pancreatic cancer: a case report

A 45-year-old woman presented with upper abdominal and back pain. A cystic lesion in the pancreas and inflammation around the splenic artery were detected by computed tomography. Although imaging studies were difficult to exclude malignancy, pathological and cytological findings of a fine-needle aspiration showed no signs of malignancy. The patient was, therefore, followed-up for 3 months, during which time the cyst increased in size and developed a cyst-in-cyst structure. She was diagnosed with mucinous cyst neoplasm and underwent distal pancreatectomy. Histologically, the patient was diagnosed as low-grade mucinous cystic adenoma. Soft tissue shadows around the splenic artery were considered to indicate fibrosis and infiltration of inflammatory cells. After distal pancreatectomy, the patient has been uneventful with symptom resolution. This case highlights the potentially atypical presentation of mucinous cystic neoplasms with inflammatory cell infiltration around the splenic artery.