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.
VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1051828790117127.