A 55 year old female with a history of epigastric pain and weight loss during the last year underwent an abdominal computed tomography (CT) that reveled multiple focal hepatic lesions, consistent with metastases, and a cystic lesion with 20mm in the tail of the pancreas, without clear invasion of the nearby structures (Figure 1).
Figure 1. CT scan showing a pancreatic lesion and multiple hepatic metastasis.
The patient was then submitted to an endoscopic ultrasound (Figure 2), that showed a 25mm solid lesion in the body of the pancreas invading the splenic vein and that conditioned marked dilatation of the pancreatic duct. On elastography this lesion displayed a blue heterogeneous pattern. There were also multiple solid lesions in the liver, some with cystic areas.
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Figure 2. EUS reveling (a) a solid pancreatic tumor with blue heterogeneous pattern; (b) dilatation of the pancreatic duct and (c) solid liver lesion with cystic component.
We proceeded to fine-needle aspiration (25G) of both pancreatic and hepatic lesions. The cytological examination was compatible with a pancreatic neuroendocrine tumor (Figure 3)
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Figure 3. FNA cytological examination on hematoxylin and eosin stain (a) and immunohistochemical study with chromogranin (b) and synaptophysin (c).
Commentary
Pancreatic neuroendocrine tumors (PNET) represent approximately 3 percent of primary pancreatic neoplasms1 and 32% to 73% of cases are metastatic at diagnosis. The most common presenting symptoms of a nonfunctioning PNET are abdominal pain, weight loss, anorexia and nausea. CT scans are normally the first imagiologic technique used on evaluating PNET, with great accuracy; however, sensitivity is decreased for tumors smaller than 2 cm in diameter2. These small tumors can often appear as vascular, hypodense or cystic lesions. Endoscopic ultrasonography (EUS) is highly accurate for detecting primary pancreatic NETs with high sensitivity (82%) and specificity (95%), and it can detect lesions as small as 2 to 3 mm in diameter2. One report showed that EUS had higher sensitivity than helical, contrast-enhanced CT scan (92% versus 63%)2, adding the possibility to perform fine-needle aspiration (FNA) that provides a non-operative histologic diagnosis of PNET. Another benefit of EUS is the capability to use elastography, which is a method for real-time evaluation of tissue stiffness. This method provides specific patterns supporting the benign or malignant nature of solid pancreatic lesions4, with high sensibility (95%) and specificity (62%)5. In case of a negative EUS-FNA, the blue pattern on EUS elastography of this lesion should lead to further evaluation, either repeat the FNA or consider surgery.
With this case report the authors showed the adding value of EUS and its various diagnostic tools on evaluating pancreatic lesions.
References
1. Fesinmeyer MD, Austin MA, Li CI, et al. Differences in survival by histologic type of pancreatic cancer. Cancer Epidemiol Biomarkers Prev 2005; 14:1766.
2. Rösch T, Lightdale CJ, Botet JF, et al. Localization of pancreatic endocrine tumors by endoscopic ultrasonography. N Engl J Med 1992; 326:1721.
3. Khashab MA, Yong E, Lennon AM, et al. EUS is still superior to multidetector computerized tomography for detection of pancreatic neuroendocrine tumors. Gastrointest Endosc 2011; 73:691.
4. Iglesias-Garcia J, Larino-Noia J, Abdulkader I, et al. EUS elastography for the characterization of solid pancreatic masses. Gastrointest Endosc 2009;70:1101-8.
5. Mei M, Ni J, Liu D, et al. EUS elastography for diagnosis of solid pancreatic masses: a meta-analysis. Gastrointest Endosc 2013;77:578-89.
Authors:
Gonçalves BM1, Fernandes D1, Ferreira M2, Soares JB1, Bastos P1
1- Serviço de Gastrenterologia, Hospital de Braga
2- Serviço de Anatomia Patológica, Hospital de Braga