대한혜담도연구회지 1997; 2: 168-172

Adenosquamous of the : Differentiation from

Seung Jae Myung, M.D., Yeun Suk Kim, M .D ., Seung Yong Kim, M .D. Hong Ja Kim, M.D., Jeong Su Kim, M.D., Dong Wan Seo, M .D ., Sung Koo Lee, M.D., Myung Hwan Kim, M.D., and Young 11 Min, M.D.

Department of Intemal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

=국문초록=

가성낭종과 구별이 어려웠던 훼장 선편평상피암 1 여|

울산대학교 의과대학 서울중앙병원 내과학교실

명승재·김연석·김승용·김흥자·김정수 서동완·이성구·김명환·민영일

혜장의 선평편상피암은 드문 형태의 춰l 장암으로 이의 생물학적 행태와 임상적 양상은 훨씬 흔한 종류인 쉐장선암입니다 선암이나 순수한 평편상피암과 유사한것으로알려지고 있다 . 저자등은 초기에 쉐장가성낭종과의 감별이 힘들었던 드문 형태의 춰l 장 선편펑상피암 1 예를 경험하였기에 문헌고찰과 함께 보고하는 바이다 .

중심단어 선편평상피암， 춰l 장 ， 궤장가성냥종， 낭성변성

extravasation of contrast to the mass have also been 5 6 INTRODUCTION reported. - We report here an unusual case of adeno­ squamous carcinoma of the pancreas which has ini- Adenosquamous carcinoma of the pancreas is a rare tially brought some difficulties in differentiating from 1 2 form of pancreatic . • Its bi 이 ogical behavior pancreatic pseudocyst. and c\inical features are known to be similar to the much more common ductal adenocarcinoma or to CASE REPORT pure squamous cell carcinoma, another rare form of pancreatic .3.4 However, the unusual mani­ A 64-year-old man was admitted to our hospital festations of cancer with cystic degeneration and with a two-week history of epigastric pain. The patient complained that the pain was dull and 연락처 명송재， 서울시 송파구 풍납동 388-1 , 서울중앙병원 소화기 내과 continuous radiating to his back. He was a social

168 Seung Jae Myung, et al: Aden∞quamous Carcinoma of the Pancreas: Differentiation from Pancreatic Pseudocyst 169 drinker and denied use of any kind of drug medi- mild tenderness over the epigastrium, but no rebound cation. There was no history of abdominal trauma or tenderness or guarding was present. There was no diabetes mellitus. No fever, chills, , or weight hepatosplenomegaly or palpable mass. Laboratory loss was reported. Family histoη was unremarkable. tests incIuded white blood count 8,100 cellsjmm3, On physical examination, the patient was thin and hemoglobin 13.6 gjdl, amylase 263 UjL (60-210 UjL), not in the state of acute distress. He complained of and Iipase 461 UjL (66-220 UjL). Liver function test and tumor markers (CAI9-9 and CEA) were within the norrnal Iimit. An abdominal CT scan revealed a 3- to 4-cm sized ovoid and -Iike lesion in the region of the pan­ creatic head (Fig. 1). The was mildly dilated, however, the parenchyma of the pancreatic body and tail showed no specific abnorrnal findings. Endoscopic retrograde balloon pancreatography (ERP) showed about a 2 cm segmental narrowing of the main duct at the head portion of the pancreas and

mild upsπeam dilatation (Fig. 2A). In the pancreatic head, round contrast pooling in communication with Fig. 1. Abdominal CT scan showing 3- to 4-cm sized ovoid cyst-like lesion in the region of the pan- the main duct was noted (Fig. 2A). Brush cytology creatic head. revealed no malignant cells but many sheets of ductal

Fig 2. A. Endoscopic retrograde balloon pancreatogram (ERP) showing segmental narrowing (arrow) and mild up­ stream dilatation of the main pancreatic duct and round pooling of the contrast at some distance (arrow head). B. Magnetic resonance cholangiopancreatography revealing pancreatic ductal change similar to the find­ ings on ERP and round cystic lesion in the pancreatic head. 170 대한혜담도연구회지 제 2 권 제 2 호 1997 epithelial cells. Magnetic resonance cholangiopancrea­ poorly demarcated mass with a cystic cavity was tography showed pancreatic ductal change similar to resected (Fig. 3). Upon histological examination, the the findings on ERP and a round lesion with cystic tumor was composed mainly of nests of malignant character in the pancreatic head (Fig. 2B). squamous cells with areas of adenocarcinoma which The clinical features and radiological fmdings were was compatible with adenosquamous carcinoma of the felt most consistent with a pancreatic pseudocyst and pancreas (Fig. 4) πle postoperative course was un- benign stricture secondary to chronic , although a cystic tumor or ductal carcinoma could not be ruled out. A pancreatic stent was inserted to relieve the stasis in the pancreatic duct, and supportive care including NPO and total parenteral nutrition was com­ menced. Even after four weeks of medical therapy, the patient still complained about the persistence of . Follow-up ERP showed no change of the ductal narrowing in the main pancreatic duct but the cyst-like lesion in the region of the pancreatic head showed enlargement on follow-up CT scan. Cytologic findings from needle biopsy of the pan­ creatic head were interpreted as adenosquamous carci­ Fig 3. Macroscopic appearance of the adenosquamous 6 7 carcinoma of the pancreatic head. Poorly de­ noma. • The patient underwent pylorus preserving marcated firm infiltrating mass with cystic pancreatoduodenectomy and a 3.5 x 3 X 2.8 cm sized change was noted

Fig 4. Photomicrograph of the transitional zone where adenocarcinoma and squamous cell carci­ noma are seen m contact. Seung Jae Myung, et al: Aden∞quamαIS Carcinαna of the Pancreas: Differentiation from p，외1σ'eatic Pseudocyst 171 eventful and the patient was doing well at 4-month creatic duct. Pain relief and the resolution of the follow up. pseudocyst were expected. lO,11 Even after four weeks of medical treatment, the patient’s symptoms had not DISCUSSION been improved. Follow up ERP showed no change of ductal stricture, and abdominal CT scan showed Adenosquamous carcinoma of the pancreas, often enIargement of the previously noted cyst-like lesion. called adenoacanthoma, is a rare variant of nonendo­ πle cytologic findings from the needle biopsy sug­ crine pancreatic cancer. 1,2 까le collective incidence of gested adenosquamous carcinoma of the pancreas, this malignancy has been estimated at 1 - 4 % of which was confirmed by surgical resection of the pancreatic ,3-4,8 even though higher rates tumor. 1,9 of 9-11 % have been reported in Japan.'" Some au- Aside from having a rare type of pancreatic tumor, thors have suggested that pure squamous cell carcino this patient exhibited very unusual features which led ma behaves more aggressively,8 however, literature us to an erroneous initial diagnosis. This case showed review shows no significant differences in age pre­ extravasation of ERP contrast into a tumor cavity due valence, sex ratio, distribution of cancer in the pan­ to cystic change, as well as ductal communication to creas, neoplastic behavior, or prognosis among adeno­ the cystic portion of the tumor. These findings can squamous carcinoma, ductal cell carcinoma, and pure occur in a cystic with ductal communication 2-5 squamous cell carcinoma of the pancreas. or in a pseudocyst associated with pancreatitis or Our patient was initially managed under the diag­ tumor. Extravasation of the contrast to the ductal cell nosis of chronic pancreatitis with pseudocyst because carcinoma is possible,12 however, pooling of the of his pain compatible with pancreatitis and the ele- contrast at some distance from the main duct or round vated pancreatic enzymes. Radiologic fmdings sup­ accumulation of the contrast shown in our case is an ported our first conclusion. Segmental narrowing of uncommon finding. πlese findings are quite unusual the main pancreatic duct suggesting benign stricture for adenosquamous carcinoma of the pancreas as well, 5,6 was detected on ERP. The lesion in the pancreatic although a few similar cases had been reported. J ,U Our head was almost purely cystic and it did not exhibit case and previous cases suggest that this rare pan­ a definite mass on CT (Fig. 1). Brush cytology creatic malignancy can be misdiagnosed as pancrea­ revealed no malignant cells, a1though a sufficient titis with pseudocyst. In adenosquamous carcinoma of number of cells had been taken. However, there also the pancreas, ductal communication with cancer may were several fmdings that were not consistent with be expected since this rare malignancy may arise from chronic pancreatitis. The parenchyma of the pancrea­ the malignant degeneration of squamous metaplasia of 1 tic body and tail did not show the changes of chronic pancreatic ductal . inflammation, such as swelling, fluid collection, or In summary, we report a case of adenosquamous calcification on CT scan. The dilated main duct was carcinoma of the pancreas with unusual manifestation. rather smooth on ERP as well . A cystic tumor and lnitially, a cyst-like lesion in the region of pancreatic malignant neoplasm were also suspected, but clinical head was diagnosed as pancreatic pseudocyst asso­ features and radiological findings were not compatible ciated with chronic pancreatitis. Our case emphasizes with both conditions. that this rare pancreatic tumor can be difficult to The patient was managed by stenting of the pan- differentiate from a benign condition, such as pan- 172 대한쉐담도연구회지 · 제 2 권 제 2 호 1997 creatic pseudocyst, thus mislead the physician into of the pancr않s : Report of an unusual case and review of the literature. Dig Dis Sci 1992; 37: 312-8. arriving at an initial misdiagnosis. 6. Wi\czynski SP, Vanente PT, Atkinson BF: Cyto­ diagnosis of adenosquamous carcinoma of the pan­ Key Word: Pseudocyst, Pancreas, Adenosquamous creas: Use of intraoperative fine needle aspiration. carcmoma Acta Cytol 1984; 28: 733-6. 7. Smit W, Mathy JP, Donaldson E: Pancreatic cytology and aden∞quamous carcinoma of the pancr않S. Patho­ REFERENCES logy 1993; 25: 420-2. 8. Baylor SM, Berg JW: Cross-c\assification and survival characteristics of 5,000 cases of cancer of the pan­ 1. Ishikawa 0 , Matsui Y, Aoki 1, Iwanaga T, Terasawa creas. J Surg Oncol 1973; 5: 335-58. 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