2017 Volume 56 Issue 5 Pages 237-243
Background : Solid pseudopapillary neoplasm (SPN) of the pancreas is an uncommon, low-grade malignant tumor with uncertain histogenesis, which occurs predominantly in young women. Herein, we report an extremely rare case of a clear-cell variant of SPN diagnosed by endoscopic ultrasound-guided fine needle aspiration cytology (EUS-FNA).
Case : A 44-year-old woman presented to us with a tumor of the body of the pancreas detected by computed tomography at another clinic. Since the findings of imaging led to the suspicion of SPN of the pancreas, EUS-FNA was performed for obtaining a definitive diagnosis. Many tumor cells were observed on the smear, the majority of which were relatively small, having clear, vacuolated cytoplasm ; there was no marked increase of the nuclear-cytoplasmic ratio. Since a small number of the cells was distributed in clusters or arranged in a pseudorosette-like pattern, pancreatic neuroendocrine tumor (PNET) was considered in the differential diagnosis. From a comprehensive consideration of the clinical and cytological findings, we conclusively judged that the tumor was a SPN of the pancreas. The tumor was then definitively diagnosed as a clear-cell variant of SPN of the pancreas by histopathologic examination of the surgically resected specimen.
Conclusion : Although it needs to be differentiated from PNET, the clear-cell variant of SPN of the pancreas could be suspected based on precise observation of the cellular morphology and consideration of the clinical findings, while keeping in mind the possibility of this variant. We emphasize that immunohistochemical examination is necessary for a definitive diagnosis of the clear-cell variant of SPN of the pancreas.
