Ampullary carcinoid tumors diagnosed by endoscopic ultrasound-guided fine needle aspiration in two patients with biliary and pancreatic duct obstruction

We present two cases of ampullary carcinoid tumors diagnosed and appropriately staged by EUS-FNA.

In case 1, a 46-year-old man presented with anemia and a 4.5-kg weight loss. Laboratory analysis showed: hemoglobin 11.2 mg/dL, total bilirubin 1.4 mg/dL, alkaline phosphatase 324 U/L, aspartate aminotransferase (AST) 221 U/L, and alanine aminotransferase (ALT) 205 U/L. Colonoscopy was unremarkable.

Upper endoscopy showed an enlarged and ulcerated ampulla ([Fig. 1]).

Fig. 1 Endoscopic view of a large ulcerated ampullary subepithelial lesion in case 1.

Mucosal biopsies showed non-specific inflammatory changes. Abdominal computed tomography (CT) disclosed dilation of the main pancreatic duct and the intrahepatic and extrahepatic biliary ducts. Endoscopic ultrasound (EUS) revealed a round hypoechoic 26-mm ampullary subepithelial mass, staged as T2N1Mx ([Fig. 2]).

Fig. 2 Endoscopic ultrasound (EUS) view of the lesion in [Fig. 1]. The subepithelial lesion appears to invade the submucosal space, extending to but not invading the muscularis propria (arrows).

The pancreatic duct and bile duct were dilated up to 4 mm and 8 mm respectively. Fine needle aspiration (FNA) showed atypical cells with round, eccentric nuclei, suggestive of a low grade neuroendocrine tumor. Immunostains for synaptophysin and chromogranin A were positive.

The patient underwent pancreaticoduodenectomy. Surgical pathology confirmed a T2N1M0 carcinoid tumor ([Fig. 3]). Imaging and clinical follow-up at 6 months were unremarkable.

Fig. 3 Histological photomicrograph from the pancreaticoduodenectomy resection specimen in case 1, demonstrating a low grade neuroendocrine tumor forming nests and rosettes (arrows) in the submucosa (SM). The mucosa (M) appears intact (hematoxylin and eosin, × 100).

In case 2, a 53-year-old woman presented with painless jaundice and a 9-kg weight loss. Physical examination revealed scleral icterus and mild non-tender hepatomegaly. Laboratory analysis showed: total bilirubin 5.9 mg/dL, alkaline phosphatase 405 U/L, AST 96 U/L, and ALT 190 U/L.

Abdominal CT showed a dilated pancreatic duct and intrahepatic and extrahepatic biliary ducts. Endoscopy revealed an 18-mm ampullary subepithelial lesion, staged on EUS as T3N1Mx ([Fig. 4] and [Fig. 5]).

Fig. 4 Endoscopic view of a smooth, medium-size ampullary subepithelial lesion in case 2. The lesion was friable and demonstrated limited bleeding upon manipulation with a biopsy forceps.

Fig. 5 Endoscopic ultrasound (EUS) view of the lesion in [Fig. 4]. The subepithelial lesion obstructs both the common bile duct (CBD) and pancreatic duct, and was staged as T3N1 on this examination.

The pancreatic duct and common bile duct were dilated up to 5 mm and 13 mm respectively. FNA showed malignant pleomorphic cells with round, eccentric nuclei, suggestive of high grade neuroendocrine tumor ([Fig. 6]). Immunostains for cytokeratin, synaptophysin, and chromogranin A were positive.

Fig. 6 Air-dried fineneedle aspirate specimen from the lesion in [Fig. 5], demonstrating loosely cohesive cells with peripheral clumping of chromatin, and exhibiting a high degree of pleomorphism – all features of a high grade neuroendocrine tumor (Diff Quick stain, × 550).

The patient underwent pancreaticoduodenectomy. Histological examination confirmed a T3N1M0 high grade carcinoid tumor ([Fig. 7]). Imaging and clinical follow-up at 3 months were unremarkable.

Fig. 7 Histological photomicrograph from pancreaticoduodenectomy resection specimen in case 2, demonstrating significant cell crowding and overlap with individual cellular features similar to those seen on the fine needle aspiration smears ([Fig. 6]) (hematoxylin and eosin, × 200).

Ampullary carcinoid tumors compromise 2 % of ampullary malignancies and account for 0.3 % of all gastrointestinal neuroendocrine tumors [1]. To date, approximately 100 cases of ampullary carcinoid tumor have been reported in worldwide literature [2]. Endoscopic diagnosis is usually limited by the subepithelial nature of the tumor. EUS-FNA provides accurate diagnosis and staging of ampullary malignancies in general [3]. In a series of 41 patients with ampullary tumors, the accuracy of EUS was found to be superior to that of CT and equivalent to that of magnetic resonance imaging (MRI) for T staging (EUS 73 %, CT 26 %, MRI 54 %) and N staging (EUS 67 %, CT 44 %, MRI 77 %) [4]. The role of EUS-FNA in the early diagnosis and staging of ampullary carcinoid tumors has been described only once before in the literature in English [5].

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References

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• 2 Hartel M, Wente M N, Sido B. et al . Carcinoid of the ampulla of Vater.  J Gastroenterol Hepatol. 2005;  20 676-681
• 3 Krishna S G, Lamps L W, Rego R F. Ampullary carcinoid: diagnostic challenges and update on management.  Clinical Gastroenterol Hepatol. 2010;  8 e5-6
• 4 Chen C, Yang C, Yeh Y. et al . Reappraisal of endosonography of ampullary tumors: correlation with transabdominal sonography, CT, and MRI.  J Clin Ultrasound. 2009;  37 18-25
• 5 Defrain C, Chang C Y, Srikureja W. et al . Cytologic features and diagnostic pitfalls of primary ampullary tumors by endoscopic ultrasound-guided fine-needle aspiration biopsy.  Cancer. 2005;  105 289-297