Histopathological staging and differential diagnosis of marginal zone lymphoma of gastric mucosa-associated lymphoid tissue.

The purpose of this study was to explore the histopathological staging and differential diagnosis of marginal zone lymphoma in gastric mucosa-associated lymphoid tissue (MALT lymphoma). We performed detailed histomorphology and immunohistochemistry investigations as well as genetic testing on endoscopic biopsy and endoscopic mucosal resection specimens from 18 patients with gastric MALT lymphoma. We found that gastric MALT lymphoma typically begins as a small, isolated area outside the lymphoid follicular mantle zone or proliferates in a multifocal, patchy manner, gradually spreads to the interfollicular zone, forming diffuse proliferation, invades the gastric mucosal glands, and infiltrates or proliferates into the center of peripheral reactive lymphoid follicles. Abnormally proliferating lymphocytes invade the surrounding lymphoid follicles, resulting in damage, atrophy, and disappearance of their normal follicles as well as of the gastric mucosa glands, forming diffuse proliferation. Redifferentiation and proliferation lead to the transformation of lymphocytes; that is, MALT transitions into highly invasive lymphoma. Based on our findings in this study, we propose the following five stages in the process of development and progression of gastric MALT lymphoma: the stage of cell proliferation outside the lymphoid follicular mantle zone; the stage of heterogeneous proliferative lymphoepithelial lesion; the stage of reactive lymphoid follicular implantation; the stage of lymphoid follicular clonal proliferation; and the stage of MALT transforming into highly invasive lymphoma. We examined the differential diagnosis of histopathological features at each stage. The clinicopathological staging of gastric MALT lymphoma can help clinicians provide accurate treatment and track malignant cell transformation, thus playing a significant role in controlling its development and progression.

Analysis of clinical features of acute pancreatitis in Shandong Province, China.

AIM: To investigate and obtain a more comprehensive view of the etiology and clinical features of acute pancreatitis in China. METHOD: The study comprised 1471 patients in 10 cites of China who were admitted to hospitals for acute pancreatitis from January 1992 to December 2002. Data for each patient were collected on a standardized form. RESULTS: Of the 1471 patients (854 men, 617 women; mean age 43.3 years; range 13-82 years), 1280 had mild pancreatitis and 191 had the severe form. Cholelithiasis (20.2%), alcohol (17.3%) and diet-induced (12.4%) were the most frequent etiological factors, followed by biliary tract infections (5.6%), hyperlipidemia (2.3%) and other factors (5.1%). However, in about 36.1% of cases, the etiology of acute pancreatitis still remained unexplained. In coastal regions, cholelithiasis was the most frequent factor but alcohol ranked first in interior regions. In males, a small predominance of alcohol over cholelithiasis was seen (27.4%vs 14.3%) and there was a clear predominance of cholelithiasis over alcohol (28.4%vs 3.2%) in females. The differences in the frequency of cholelithiasis and alcohol between coastal regions and interior regions and males and females were statistically significant (P < 0.01). According to their frequency, complications of acute pancreatitis were pancreatic pseudocyst, pancreatic ascites and bacterial peritonitis, pulmonary infections, multiple organ failure, diabetes mellitus type 2 and shock. CONCLUSION: Cholelithiasis, alcohol and diet-induced factors were the main etiological factors seen in China, whereas cholelithiasis alone predominated in females and alcohol ranked first in males. In about 36.1% of cases, the etiology of acute pancreatitis remained unknown. More attention should be paid to studying the etiologies of acute pancreatitis that remain unknown.

Analysis of the clinical features of recurrent acute pancreatitis in China.

BACKGROUND: Since few systematic studies have focused on recurrent acute pancreatitis in China, we sought to investigate its clinical features, including etiological factors and relative frequency. METHODS: Patients were selected from a total 1471 patients with acute pancreatitis in ten cities of China. All had been admitted to a hospital with an attack of acute pancreatitis between January 1992 and December 2002. Data for each patient was recorded on a standardized form. RESULTS: Of the 1471 patients with acute pancreatitis, 157 (10.7%) had recurrent acute pancreatitis. The majority (63%) were male, with a mean age of 41 years (range, 13-82 years). Regarding the etiology, alcohol (20.4%) and cholelithiasis (20.4%) were the most frequent causes, followed by diet (13.4%), hypertriglyceridemia (8.3%), biliary tract infection (5.7%), other (5.1%), and idiopathic factors (26.8%). Alcohol was most frequent in male patients (30.3%), whereas cholelithiasis was most frequent (34.5%) in female patients. The majority of patients (79.6%) presented with their second attack of pancreatitis. Complications of recurrent acute pancreatitis in order of frequency were pancreatic pseudocyst, multiple organ failure, diabetes mellitus type 2, and shock. CONCLUSIONS: Recurrent acute pancreatitis remains a frequent disease, with cholelithiasis and alcohol being the most usual etiological factors. Alcohol is the primary etiological factor in male patients. In about 26.8% of cases, the etiology remains unknown.