Cystic carcinoid tumor of the pancreas diagnosed by endoscopic ultrasound-guided fine needle aspiration of the cystic wall: an unusual presentation and diagnosis.

Cystic carcinoid tumors of the pancreas represent a subgroup of malignant potential and difficult diagnosis.(

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an effective tool to evaluate these lesions.(

A 52-year old man was referred to the Hospital Israelita Albert Einstein to investigate a pancreatic cyst. Endoscopic ultrasound revealed a cystic lesion, measuring 2cm in the pancreatic tail, without septations and communication with the pancreatic duct (Figures 1 and 2). The FNA fluid showed normal amylase (67U/L) and low CEA (11,2ng/mL) levels.

Figure 1

Neuroendocrine cyst

Figure 2

After fine needle aspiration

Histological examination of fragments of the cystic wall obtained by FNA (Figure 3) revealed a carcinoid tumor, confirmed by chromogranin and synaptofisin immunohistochemistry analyses (Figure 4).

Figure 3

Endoscopic ultrasound-guided fine needle aspiration of the cyst wall

Figure 4

Cell-block of the pancreas shows numerous epithelial cells with rounded nucleus, “salt and pepper” chromatin and eosinophilic cytoplasm (Hematoxylin and eosin stain, 10x). Immunohistochemistry positive for neuroendocrine tumor

DISCUSSION

The preoperative diagnosis of cystic pancreatic carcinoid tumor is important due to their malignant potential and possibility of ressection.(

Computed tomography (CT) and EUS may not help making diagnosis, since the radiological aspect is often interpreted as a pancreatic mucinous cystadenoma, such as in this report.

EUS-FNA is a highly accurate method to diagnose pancreatic carcinoid tumors.( The few studies available show a high agreement between cytology and pathology.(

In this report a rare lesion is described, and the diagnosis was possible only after the histological study of the cystic wall fragments obtained by EUS-FNA.

This case report shows the efficacy of EUS-FNA in an unusual diagnosis.