ABSTRACT
The pancreatic neuroendocrine tumors (PanNETs) most commonly present as solid neoplasms; however, very rarely, they may present primarily as cystic neoplasms. Most of the cystic PanNETs are non-secreting tumors, and the radiological features are not well defined. Hence pre-operative diagnosis is usually challenging and the tumors are misdiagnosed as mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, serous cystic neoplasms, solid pseudopapillary neoplasms, and non-neoplastic cysts. However, the management depends on the accurate diagnosis of these cystic lesions, which poses a dilemma. Herein, we report the case of a cystic PanNET in the tail of the pancreas, which was clinically and radiologically misdiagnosed as a mucinous cystic neoplasm. This case is reported to highlight this issue to the medical community regarding the diagnostic difficulty in such rare non-functioning pancreatic neuroendocrine tumors.
Subject(s)
Humans , Male , Middle Aged , Pancreatic Cyst/diagnosis , Neuroendocrine Tumors/diagnosis , Pancreatic Intraductal Neoplasms/diagnosis , Pancreas/pathology , Neoplasms, Cystic, Mucinous, and Serous/diagnosis , Rare Diseases , Diagnostic ErrorsABSTRACT
Neurofibromatosis type‑1 (NF‑1) is an autosomal dominant disorder, with increased risk of developing benign and malignant tumors of the gastrointestinal tract (GIT). However, the synchronous presence of multiple GIT stromal tumors and duodenal submucosal somatostatinoma, like in this 50‑year‑old female NF‑1 patient, is very rare. She presented with hematemesis, malena, along with multiple neurofibromas all over the body. Thorough radiological and peroperative work‑up revealed multiple ulcerated submucosal and serosal nodules in the proximal small intestine. Histological work‑up revealed diagnosis of a duodenal submucosal somatostatinoma with multifocal serosal gastrointestinal stromal tumors. This case is being reported to highlight the rare coincidence of multiple GIT tumors in an NF‑1 patient.
ABSTRACT
Modification of A. conoides beta-glucosidase by diethylpyrocarbonate caused rapid inactivation of the enzyme. The kinetic analyses showed that the inactivation by diethylpyrocarbonate resulted from the modification of an average of one histidine residue per mole of enzyme. The modified enzyme showed an increase in absorbance at 240 nm. Sulphydryl, lysine and tyrosine residues were not modified by diethylpyrocarbonate treatment. The substrate offered significant protection against diethylpyrocarbonates modification. The results indicate that diethylpyrocarbonate was interacting with the enzyme at or near the active site.