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Abdominal CT scan. The tumor showing a heterogeneous multiloculated cystic mass with low density in the tail of the pancreas (white arrow), compressing the adjacent organs.
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Squamous metaplasia presenting in noninvasive mucinous cystic neoplasm (MCN) of the pancreas is extremely rare. We described a case of 39-year-old Chinese female with a 5-year history of a slow growing mass in the left upper abdomen and an 18-month history of surgical incision exudation. The patient underwent cystojejunostomy, laparotomy and distal...
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Context 1
... ultrasonog- raphy and computer tomography scan revealed a 7.8 cm × 7.3 cm, heterogeneous hypoechoic or low- density mass with poorly defined margins in the tail region of the pancreas, compressing other adjacent organs. The mass was composed of several large loculi with an irregular thickening of the cyst wall and papil- lary excrescences projecting into the cystic cavity ( Figure 1). Splenomegaly was also found. ...Citations
... Based on the degree of dysplasia of the surface epithelium, the World Health Organization subcategorizes non-invasive MCNs into MCNs with low, intermediate or high-grade dysplasia [4]. MCNs with extensive squamous metaplasia of the epithelium are extremely rare, with only one previously reported case in the literature [5]. We report a unique case of non-invasive pancreatic MCN with extensive squamous metaplasia and highlight the importance of recognizing this unusual feature. ...
... Extensive squamous metaplasia is very rare. To our knowledge, Li et al [5] reported the only case of extensive squamous metaplasia of an MCN of the pancreas. They described a 39-year-old woman with a cystic mass in the tail of the pancreas, which was resected and revealed a cyst lined by columnar mucin-producing epithelium with intermediate-grade dysplasia and areas of extensive squamous metaplasia. ...
... Despite complete sampling of the cyst and meticulous microscopic examination, we were unable to identify any obvious cyst-lining columnar epithelium. This may be attributed to extensive replacement [5] suggested that squamous element might be derived from squamous transdifferentiation of the adenomatous element or derived from pluripotent stem cells. In the current case, we observed dense lymphoplasmacytic inflammation of the underlying stroma, with focal xanthomatous change and focal ossification. ...
... Although a clear cell variant and a chromogranin A negative SPN has already been reported, our case did not show nuclear β-catenin nor vimentin expression, therefore ruling out SPN [16,18]. MCN is not connected to the pancreatic duct system and contains epithelium (in rare cases squamous epithelium), surrounded by an ovarian- like stroma that stains positive for progesterone receptor, inhibin, CEA, and chromogranin A [19]. Moreover, the epithelial component of MCN is positive for MUC5AC and negative for MUC1 and MUC2, obviously in difference to our results [2,20]. ...
Intraductal tubulopapillary neoplasms of the pancreas are very rare tumors characterized by intraductal tubulopapillary growth, ductal differentiation, scant intracellular mucin production and cellular dysplasia. Here, we report the first case of an intraductal tubulopapillary neoplasm of the pancreas with clear cell morphology. The tumor was detected during the diagnostic work-up of acute pancreatitis in a 43- year old female. Histological examination revealed a tumor with the typical architecture of an intraductal tubulopapillary neoplasm of the pancreas with tumor cells showing abundant clear cytoplasm and Di-PAS negativity. Immunohistochemistry revealed positivity for Pan-CK, CK7, CK8/18, MUC1, MUC6, carbonic anhydrase IX, CD10, EMA, β-catenin and e-cadherin. Sanger sequencing did not detect mutations for β-catenin, BRAF, KRAS, PIK3CA and GNAS. Altogether, histology, immunohistochemical expression profile (MUC1+, MUC6+, MUC2-, MUC5AC-, thrypsin-, chymotrypsin-, CDX2-) and sequencing results led to the diagnosis of intraductal tubulopapillary neoplasm. However, the neoplasm consisted of cells showing abundant clear cytoplasm, a morphological pattern not being described so far in the current classification of pancreatic intraductal neoplasms. Potential differential diagnosis and the molecular basis of clear cell morphology are discussed. In conclusion, we consider this tumor as intraductal tubulopapillary neoplasm of the pancreas with unique clear cell phenotype. After surgery and without adjuvant therapy, the patient’s clinical course has been uneventful for over two years now.
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... Based on these histological features, it is relatively easy to differentiate SPN from ductal adenocarcinoma, as the latter is often more moderately or poorly differentiated and is composed of haphazardly arranged glands admixed with a dense desmoplastic stroma [9]. Cystic neoplasms, such as mucinous or serous cystic neoplasms, can also be easily differentiated from SPN, because they lack communication with the pancreatic duct system and have no mucinous or serous epithelium, which is typically supported by an "ovarian" stroma [10]. Neuroendocrine tumors, especially the welldifferentiated ones，are the most important entities in the differential diagnosis of SPN; this is because they may display similar light microscopic features, and neuroendocrine markers are variably expressed in SPN [8]. ...
... It is relatively easy to differentiate SPT from ductal adenocarcinoma based on these histological features, as the latter is ofter more moderately or poorly differentiated and is composed of haphazardly arranged glands admixed with a dense desmoplastic stroma [14]. Cystic neoplasms, such as mucinous or serous cystic neoplasm, can also be easily differentiated from SPT, because they lack communication with the pancreatic duct system and have no mucinous or serous epithelium usually supported by an "ovarian" stroma [15,16]. Neuroendocrine tumors, especially the well-differentiated ones, are the most important entities in the differential diagnosis of SPT, because they may display similar light microscopic features, and neuroendocrine markers are variably expressed in SPT [1,2]. ...
Solid pseudopapillary tumor (SPT) of the pancreas is a rare pancreatic tumor with low malignant potential. It occurs characteristically more often in young women. SPT associated with extra- and pancreatic anomalies are occasionally reported. Here we report a case of pancreatic SPT with concomitant urogenital malformations including solitary kidney and uterus didelphys in a 25-year-old woman. The patient underwent central pancreatectomy, and SPT was confirmed with pathological results. Recurrence or metastasis was not found after 14 months of follow-up.
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The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4264758678755142
Lymphoepithelial cysts (LECs) of the pancreas are rare, benign pancreatic cysts comprising approximately 0.5% of all pancreatic cysts. They occur predominantly in men in the 5th and 6th decades of life. LECs are true cysts lined by stratified squamous epithelium with adjacent subepithelial lymphoid tissue. They range in size from 1.2 to 17 cm (mean size 4.6 cm) and can arise in any part of the pancreas. 1 LEC resembles other benign and malignant pancreatic cysts clinically and radiologically. The cytomorphologic features of LECs have been described in a small number of case reports and it has been indicated that features may overlap with other benign and malignant pancreatic lesions. Herein, we report clinical, radiological, cytological and histopathological features of a pancreatic LEC in a 62-year-old male.
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.
