Signet ring carcinoma of ampulla of vater.

Signet ring carcinoma is a common type of adenocarcinoma of stomach but its occurrence in ampulla of Vater is extremely rare. There are only a few previous reported cases of signet ring carcinoma of ampulla of Vater. Here we reported a 61-year-old woman with obstructive jaundice. Ultrasonography and computed tomography (CT scan) examination showed intra- and extrahepatic bile duct dilatation. Endoscopic examination with biopsies revealed a small-size mass in ampulla of Vater with diagnosis of signet ring carcinoma. On consequent pancreatoduodenectomy the tumor was diagnosed as T2N0M0, stage IB. Because of the specific site of signet ring carcinoma of ampulla of Vater, the tumor seems to present itself at an early stage of disease. We review in the literature to suggest our idea.

INTRODUCTION

Most Signet-ring cell carcinomas arise in stomach mucosa but it could appear in intestine and even in other organs than gastrointestinal tract. The World Health Organization (WHO) defines this tumor as a special type or a variant of gastrointestinal adenocarcinoma.[1] This tumor rarely has been happen in ampulla of Vater in pure form or in combination with usual type of adenocarcinoma. It seems that the prognosis of this tumor in ampulla of Vater is better than in stomach.[2] We reported our case of pure signet ring carcinoma of ampulla of Vater and review previously reported cases.

CASE REPORT

A 61-year-old woman was admitted to the Al Zahra hospital in Isfahan, Iran, in 2011 with occasional jaundice and generalized pruritic for 4 months; also, she complained of 7 kg weight loss during this period. She had no symptoms of nausea, vomiting, or abdominal pain. She had a past history of diabetes mellitus and blood hypertension. Physical examination was not contributory. In initial investigation, the laboratory test results demonstrated the rising level of glutamate-pyruvate transaminase, glutamic-oxaloacetic transaminase, alkaline phosphatase, γ-glutamyl transferase, and mild increase in total bilirubin and direct bilirubin. Ultrasonography indicted extra and intrahepatic biliary duct dilatation and increased common bile duct diameter. At endoscopic retrograde cholangiopancreatography (ERCP), the tumor of papilla of Vater was revealed and dilated intrahepatic and common bile duct with distal rat tailing was shown after dye injection [Figure 1]. Biopsies taken during ERCP were diagnosed as signet ring carcinoma. Subsequence CT scan indicated intra- and extrahepatic ducts dilation, there were no obstructive mass or adenopathy. Liver, spleen, stomach, and pancreas were normal. At last the patient underwent a Whipple resection. On macroscopic examination there was polypoid mass at ampulla of Vater measured about 0.8 × 1 × 1 cm. pancreas and duodenum were normal. On microscopic examination the, malignant epithelial cells had intracytoplasmic mucin and individually infiltrating pattern that invaded to duodenal wall [Figure 2]. Regional lymph nodes were not involved. The ampullary carcinoma was diagnosed as T2N0M0, Stage IB according to the International Union Against cancer TNM classification (UICC).[3]

Figure 1

Dilated intrahepatic and common bile duct with distal rat tailing

Figure 2

Signet ring cells with intracytoplasmic mucin

DISCUSSION

Signet ring carcinoma is a type of adenocarcinoma that has unique appearance because of discohesive pattern of proliferation and intracytoplasmic accumulation of mucin.[4] Most of Signet ring carcinoma arise from stomach (90% of all signet ring carcinoma) and is about 15% to 30% of all gastric cancer, but in other gasterointestinal tract like colon its occurrence is fewer and is about 1% of all cancer.[156] In stomach, signet ring carcinoma arise from epithelial cell of mucous neck or foveola. It has a tendency to develop in a younger age group (<45 year) than the intestinal-type adenocarcinoma and is associated with a poor prognosis.[6] Signet ring carcinoma rarely has been seen in the ampulla of Vater. Sekoguchi et al. was first described signet ring carcinoma mixed with adenocarcinoma of ampulla of Vater in 1979.[2] The first reported case of pure signet ring carcinoma of ampulla of Vater was in 1990 by Gardner et al.[7]

We review the reported cases of signet ring carcinoma of ampulla of Vater and summaries the data in Table 1. We found 20 previously reported cases in the English language literature.

Table 1

Reported cases of signet ring carcinoma of ampulla of Vater

The mean age of patients is about 69 years. The mean age of 16 patients with pure signet ring carcinoma is about 59 years, and mean age of three patients with mixed adenocarcinoma with signet ring carcinoma is 65 years, and so the mean age of affliction are similar to median age for large bowel (59-63.5 year) and are 15 years younger than signet ring carcinoma of the stomach (<45 yar).[56]

Presented symptoms were jaundice, weight loss, fever, nausea, vomiting, fatigue, abdominal pain, and abdominal distention.[891011]

In four cases there was metastasis to liver, thoracic vertebra or lymph node, the case with liver metastasis had not jaundice until abdominal exploration.[1112]

As for diagnosis of signet ring carcinoma of ampulla of Vater, CT scan and ultrasound only showed a dilated CBD without an apparent mass lesion in the ampulla of Vater, therefore these techniques could not reveal malignant etiology but some authors note that contrast-enhanced ultrasound may have effective diagnostic benefits for ampullary stenosis by dividing tumorous from nonmalignant stenosis.[5]

Macroscopic appearance was often superficial protruding,[13] ulcerative, or diffuse infiltrative.

Histologically, the origin of signet-ring cells may be as the following: (1) ectopic gastric mucosa, (2) gastric-type metaplasia, and (3) differentiated from common adenocarcinoma. These conclusions are due to accompaniment situations of the disease.[713] Some previous immunohistochemical findings suggest that all of three hypotheses may be true; it seems that pure signet ring carcinoma is gastric type, that is, negative for CK 7 and positive for CK 20 and MUC 2, but mixed signet ring carcinoma and adenocarcinoma is pancreaticobiliary type, that is positive for CK 7 and negative for CK 20 and MUC 2.[4] The later type is the similar CK pattern to case of extra hepatic bile duct Poorly Differentiated Adenocarcinoma with Signet-ring Cell Carcinoma.[14]

The common type of treatment is Pancrea-ticoduodenectomy, if the patients have discovered at early stage of carcinoma of the ampulla of Vater, a pyloric-preserving pancreaticoduodenectomy is better to be done because the preservation of the whole stomach and pyloric ring may reduce postoperative complications, without decreasing curability.[19] There is no standard postoperative adjuvant therapy regimen for patients with this tumor. Nabeshima et al. reported the effectiveness of 5-fluorouracil and leucovorin in increasing the survival time with a good quality of life.[112]

For our patient the whipple surgery was done but without pyloric - preserving procedure because of unknown stage of tumor.

The prognosis of signet ring carcinoma of ampulla of Vater is better than stomach and discover in the earlier stage due to precocious jaundice of disease. Of 21 patients with signet ring carcinoma of ampulla of Vater, seven cases were at stage IB and six cases were at stage IIA. The 5-year survival rate for gastric signet ring carcinoma is 16.2%. Although the previous cases did not have long-term follow up but findings are suggested that signet ring carcinoma of ampulla of Vater has better prognosis.[1]

CONCLUSIONS

The signet ring carcinoma rarely occurs in ampulla of Vater but it should be in different possible diagnosis for the patients with obstructive jaundice. Despite the insidious pattern of development and poor outcome that this tumor shows in stomach but this tumor present itself at the early stage of disease in ampulla of Vater that may be due to its specific site and early symptom of jaundice.