A case of squamoid cyst of pancreatic ducts

Squamoid cyst of pancreatic ducts: A case report

The term squamoid cyst of pancreatic ducts (SCOP) has been proposed recently, and it is a very rare benign lesion. We report a case of SCOP in a patient who underwent laparoscopic distal pancreatectomy. A 51-year-old woman presented with a pancreatic cystic lesion (3.3 cm) as an incidental finding on abdominal ultrasonography. A computed tomography scan showed a well-defined cystic lesion in the body of the pancreas with peripheral nodular calcification. Histology showed a unilocular cyst with a thin, fibrotic wall, and it was surrounded by normal-appearing pancreatic tissue. The lining of the cyst was composed of stratified non-keratinized squamous epithelium without significant nuclear atypia. Immunohistochemistry showed positive nuclear p63 expression in the cyst lining. The final diagnosis of SCOP was established. It is important to distinguish SCOPs from mucinous pancreatic cysts that have malignant potential. Preoperative diagnosis of SCOP is still difficult, and further studies are needed to identify specific preoperative characteristics that can accurately distinguish this lesion.

Intraductal papillary squamous neoplasm of the pancreas: Cyto-histologic correlation of a novel entity

We correlate the cytologic and histologic features of a squamous-lined pancreatic cystic lesion with a complex papillary architecture and an associated KRAS mutation, which to our knowledge has not been previously described. A 69 year-old woman presented with intermittent left upper quadrant pain. CT imaging revealed a 1 cm solid lesion in the pancreatic tail with peripheral calcification. Endoscopic ultrasound-guided fine needle biopsy showed a proliferation of epithelial cells with fibrovascular cores. An immunohistochemical stain for p40 was positive in the lesional cells. A distal pancreatectomy revealed a unilocular, cystic, well-circumscribed, soft and friable mass measuring 1.0 × 1.0 × 0.8 cm. Histologically, the cyst was lined by nonkeratinizing stratified squamous epithelium with a complex papillary architecture, filling the cyst lumen. Molecular sequencing revealed a KRAS G12V missense mutation. While the lesion shared some histologic features with the previously described "squamoid cyst of the pancreatic ducts", the complex papillary architecture and presence of a KRAS mutation are unique to the entity we describe herein and we propose the name "intraductal papillary squamous neoplasm of the pancreas." Reporting the cytomorphologic features of this novel entity may help in identification of similar lesions and understanding of the clinicopathologic significance.

Pancreatic hamartoma: a case report and literature review

Background

Pancreatic hamartoma is an extremely rare benign disease of the pancreas. Only 30 cases have been reported to date.

Case presentation

A 68-year-old man presented with an asymptomatic solid and multi-cystic lesion in the uncus of the pancreas, incidentally detected on abdominal enhanced computed tomography. The tumor was found to be a well-demarcated solid and multi-cystic lesion without any enhancement, measuring 4 cm in diameter. After 28 months of follow-up, the tumor enlarged. At 31 months after initial diagnosis, the patient underwent surgical resection because it was difficult to clinically determine whether the tumor was malignant or not. Macroscopically, the solid tumor consisted of yellow adipose tissue with a smooth thin capsule confined to the pancreatic uncus. The inner structure of the tumor consisted of multiple cysts with a white nodule between the cysts. Histologically, the solid part and the multi-cystic portion consisted of mature adipose tissue and colonization of dilated pancreatic ducts with mild fibrosis, respectively. Immunohistochemical findings revealed cytokeratin 7 and 19 positive staining in the epithelial cells of the ducts. Adipose tissue showed positive staining for S-100 protein and there were only a few MIB-1 positive cells. The tumor was then diagnosed as a pancreatic hamartoma.

Conclusion

Beside on the above findings, we suggest that the term “well-demarcated solid and cystic lesion with chronological morphological changes” could be a clinical keyword to describe pancreatic hamartomas.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0419-2) contains supplementary material, which is available to authorized users.

Squamoid cyst of pancreatic ducts: a case series describing novel immunohistochemistry, cytology, and quantitative cyst fluid chemistry

Squamoid cyst of pancreatic ducts (SCPD) is a benign pancreatic cyst often misdiagnosed preoperatively as a mucinous cyst. The histopathologic features are well described but the cytology and quantitative fluid chemistry profiles from fine-needle aspiration have not been reported. This case series discusses the cytology and cyst fluid chemistry profiles in 2 SCPDs and describes morphologic and immunohistochemical features that have not been previously reported. Fine-needle aspiration of 2 SCPDs yielded acellular debris lacking mucin or exfoliated squamous cells. Two cysts had elevated fluid carcinoembryonic antigen (CEA) and amylase levels. Positive immunohistochemical staining included cytokeratin 5/6, pCEA, synaptophysin, and chromogranin (both focal). MUC2 and MUC5AC showed negativity in all cases, while PAX8 showed negative nuclear staining. An accurate preoperative diagnosis of SCPD is potentially difficult in the setting of elevated fluid CEA levels, and acellular cytology as a mucinous cyst cannot be confidently excluded.

Non-neoplastic epithelial cysts of the pancreas: a rare, benign entity

OBJECTIVES

With the increased use of cross-sectional radiologic imaging in recent years, cystic lesions of the pancreas are being diagnosed with greater frequency. While pseuodocysts have historically accounted for the majority of benign pancreatic cysts, there are a number of rare, benign cystic lesions of the pancreas that can mimic neoplastic cysts. The objective of this study was to review a single institution's experience with these benign cystic lesions of the pancreas.

METHODS

We conducted a retrospective analysis of all patients who underwent surgical resection for pancreatic disease from 2005 to 2012 at our institution. Out of a total of 947 pancreatic resections, we identified those cases performed for cystic disease, and focused upon the clinicopathologic data of patients with non-neoplastic pancreatic cysts.

RESULTS

Of the 947 pancreatic resections, 256 (27%) were performed for cystic disease. Sixteen cases (6.3%) out of the total of 256 pancreatic operations performed for cystic disease were found to have non-neoplastic cystic lesions of the pancreas. Preoperative imaging revealed primary lesions in all patients, eight of which were found incidentally. Of these lesions, 14 were suspected preoperatively to be mucinous neoplasms and two to harbor pancreatic adenocarcinoma. However, postoperative pathology revealed eight patients with ductal retention cysts, three squamoid cysts, one mucinous non-neoplastic cyst, one congenital ciliated foregut cyst, one lymphoepithelial cyst, and two endometrial cysts. Two patients had complications postoperatively, one pancreatic fistula and one SMV thrombosis. Both complications resolved with conservative management.

CONCLUSIONS

Non-neoplastic epithelial pancreatic cysts are rare, benign lesions. In our institutional experience, these lesions are often indistinguishable from cystic neoplasms of the pancreas preoperatively. As such, many of these lesions are resected unknowingly. It is important for the clinician to be well informed of the nature of these lesions, in the hopes to avoid unnecessary resection whenever possible.

Case report of a pancreatic squamoid cyst

Squamoid cyst of the pancreas is a very rare disease and it has been proposed only recently as a distinct pathologic lesion. We herein present a case of pancreatic squamoid cyst in a patient who underwent laparoscopic resection. A 60-year-old woman had an abdominal computed tomography (CT) scan for a routine check-up, and a multi-cystic lesion of 1.8-cm in size was incidentally found in the tail of the pancreas. Biochemical laboratory tests were within normal limits. At first, we presumed that the most likely diagnosis of the cystic lesion was an intraductal papillary mucinous neoplasm. To treat this lesion, we performed laparoscopic spleen-saving distal pancreatectomy. The patient showed the usual routine postoperative course and she was discharged 10 days after surgery. On examination of the resected specimen, a well-defined, oligolocular cystic mass was found in the pancreatic tail, without a solid portion. Histologic examination revealed that the cysts had linings ranging from flat squamoid cells to transitional cells with non-keratinization. After immunohistochemical staining, the final diagnosis was confirmed to be squamoid cyst of the pancreas. This lesion appears to be regarded as a benign entity, thus an extended operation should be avoided and resection of the lesion can be performed minimally.

Pancreatic Cystic Lesions of Nonmucinous Type

Cystic lesions of nonmucinous type can arise within the pancreas or can develop from adjacent structures and appear to involve the pancreas. In addition, some typically solid masses can become cystic or can present as cystic lesions. Nonmucinous cysts can be neoplastic, inflammatory, reactive, or congenital. The vast majority of neoplastic nonmucinous cysts are benign. Because of the difficulty in determining the neoplastic potential of a pancreatic cyst preoperatively, many non-neoplastic cysts are resected. This article reviews the surgical pathology of nonmucinous cysts.