膵癌と鑑別困難であった慢性膵炎の1例

A Case of Chronic Pancreatitis Hardly Differentiated from Pancreatic Cancer

　近年内視鏡的膵胆道造影（以下EPCGと略す）の発達導入により膵疾患の診断能は飛躍的に向上した^1)～4)．しかし本法による膵癌と慢性膵炎の診断基準は現在もっとも議論の多い問題の1つである²⁾⁵⁾．今回われわれは，いわゆる狭窄型を示し，EPCG上膵癌としか読影できないほどの所見がみられたが，臨床経過およびその後施行したEPCG所見などより慢性膵炎と診断した1症例を経験したので報告する．

　A 56-year-old man was admitted with complaints of jaundice, diarrhea and anorexia. Physical firding on admission showed hepatomegaly. Laboratory data were as follows: icterus index 45 units, alkaline phosphatase 8.2 units (Bessy-Lowry), s-GOT 50 units (Karmen). From these results obstructive jaundice was considered. However, jaundice disappeared soon and alkaline phosphatase returned to normal level, and only high level of serum amylase persisted. Hypotonic duodenography showed enlargement of pancreas head and liver biopsy revealed cholestatic hepatitis with submassive necrosis. PS test showed disturbance of pancreatic external secretion; low value of peak concentration of HCO₃, but enough volume of pancreatic juice. Cytological examination done at the same time gave negative results. EPCG revealed stenosis of main pancreatic duct at about 5 cm away from papilla Vater with dilatation and beading of the distal part. These findings were consistent with stenotic type of pancreatic cancer. However, diagnosis of chronic pancreatitis was also possible, because he did not complain abdominal pain during his whole clinical course; disappearance of jaundice was followed by improvement of the subjective symptoms, and because he was a heavy drinker taking around 0.9 liter of sake daily for the last 20 years. He was followed up in the out-patient clinic. About 8 months later, EPCG was repeated. The pancreatogram was almost same as that of previous examination. Thus, a diagnosis of chronic pancreatitis seems to be confirmed. Now, two and half years have passe since the onset of his illness with no medical problem.

　In such a case diagnosis should be made with great care and repeated EPCG is very helpful and reliable for confirmation of diagnosis.