I. Clinical manifestations
The symptoms of most gallbladder polyps are similar to those of chronic cholecystitis, mainly manifesting as mild discomfort in the right upper abdomen, biliary colic when accompanied by stones, often with dyspeptic symptoms such as diarrhea, nausea, vomiting, aversion to oil, etc. Very few patients have fever, jaundice, and the main signs are right upper abdominal area The main signs are pressure pain in the right upper abdominal area and radiation to the right shoulder and right back, which is more obvious. The effects on human body are mainly manifested in abnormal digestive system, abnormal liver function, and cancer in 8% to 15% of patients.
It is generally believed that gallbladder polyp is a precipitating factor of gallbladder cancer. In recent years, there are many reports about gallbladder polyp cancer at home and abroad, especially when it is accompanied by stones, the chance of cancer is significantly increased.
Diagnosis
The most commonly used and most economical way to confirm the diagnosis of gallbladder polyps is ultrasound, color ultrasound, CT, MRI, cholangiography, etc. The detection rate of <5mm can reach more than 90%, and the sensitivity and accuracy of diagnosis are higher. Because of the small size of gallbladder polyps, they are easily missed in CT and MRI, and cholangiography is painful and dangerous, so it is rarely used.
Gallbladder polyps mainly rely on ultrasound examination to diagnose gallbladder polyps, but it is often difficult to characterize them, and the clinical differential diagnosis of benign and malignant is also more difficult. The echogenicity of the lesion, the thickness of the tip, and the mucosal changes in the lesion can be valuable in differentiating benign and malignant diseases.
Differential diagnosis
(I) Clinical manifestations
Most patients with PLG and early-stage gallbladder cancer (GC) do not have obvious clinical symptoms and signs. However, the average age of onset of PLG is smaller than that of gallbladder cancer.
(II) Ultrasound features
Ultrasound is the first choice for examination of gallbladder diseases. cholesterol polyps and inflammatory polyps under ultrasound have small echogenic light masses, smooth surface, and tend to be multiple. Tumors and papillary adenomas are characterized by larger echogenic light masses. Most of the surfaces are not smooth or cauliflower-shaped, often solitary, and have a wide base. The sensitivity and specificity of endoscopic ultrasound for PLG and GC examination are above 9O%, respectively. It can accurately reflect the shape of the lesion, with smooth or nodular contours of tumorigenic lesions. The outline of neoplastic lesions is smooth or nodular with hypoechoic interior, while the outline of non-neoplastic lesions is granular. The interior of non-neoplastic lesions is granular with punctate hyperechogenicity. Color Doppler imaging allows monitoring of the blood flow in the lesion. High-flow arterial blood flow in the lesion area is an important sign of malignancy.
(C) CT, PET
Enhanced CT can compare with the surrounding organs one by one according to the change of depth of tumor being thickened by contrast agent, so as to produce the image of early GC limited thickening, which is more diagnostic advantage for tumor. Oral cholecystography CT can form a better contrast to identify isodense gallbladder polyp-like lesions. E. K. Hsu reported that smaller intracavitary filling defects on oral cholangiography CT may be benign PLG, while large intraluminal nodules (>1 or 2 cm), especially those with localized thickening of the gallbladder wall, are considered malignant or GC.
Then malignancy or GC was considered. spiral CT cholangiography and CT simulation endoscopy as well as magnetic resonance simulation endoscopy have greater clinical significance as they can clearly show the imaging changes of the three-dimensional anatomical structure of polyps in the gallbladder lumen using computer software functions. koh et al. performed PET examination using fluorine-mono-18-labeled deoxyglucose (FDG) and found that benign gallbladder lesions (cholesterol polyps and pseudotumors) had no effect on The FDG uptake was not observed in benign lesions (cholesterol polyps and pseudotumors), while malignant lesions (adenocarcinoma) showed concentrated FDG uptake. It is believed that local FDG uptake is the only indication of malignant PLG.
(iv) Tumor markers
In recent years, the positive expression of P protein and bel-2 protein in GC tissues was found to be significantly higher than that in adenomatous polyps of the gallbladder, and Itio found that the detection of human telomerase reverse transcriptase levels could improve the diagnosis of biliary tract tumors. Some studies suggest value in early diagnosis of GC patients with abnormally elevated serum estradiol levels.Fan et al. found that metalloplasmic protease I-2 expression and its ratio to metalloproteinase tissue inhibitory factor I-2 is an important marker for early diagnosis of GC and is associated with its invasion and metastasis.
(V) Pathological examination
The pathological features of gallbladder polyp-like lesions:
(1) Cholesterol polyps, yellow in appearance, papillary, with a slender tip, easily removed. Microscopically: epithelial rectangular, more lipid-engulfing foam cells are seen.
(2) Inflammatory polyp, grayish white, thick wall, microscopic: fibrous connective tissue hyperplasia, lymphocytes, plasma cell infiltration.
(iii) Adenomatous hyperplasia with rough mucosa, seen as yellow warty, papillae. Immunoenzyme markers: CEA(-), MC5(-).
Pathological features of gallbladder cancer The gallbladder wall is thickened and hardened to varying degrees, the mucosa is rough, the cancer adheres to the surrounding tissues and enlarged lymph nodes are seen, and the cut surface is grayish white. Microscopically, well differentiated cancer tissues have regular glandular lumen, deep stained nuclei and scattered nuclear division; poorly differentiated tumor giant cells appear. In some gallbladder cancer tissues, we can see more or less intestinal epithelial metaplastic cup cells, immunoenzymatic labeling: CEA is focally positive; AB-PAS and Calling aldehyde complex red staining, acidic mucus and sulfate mucus appear scattered positive.
(vi) Others
Recently, Aoki examined the mucosal structure of gallbladder by stereomicroscopic staining contrast technique, and found that the lattice-like structure in GC mucosal tissue disappeared and showed coarse granular structure, and the average maximum vascular diameter of mucosa was significantly different in normal gallbladder, chronic cholecystitis, and gallbladder cancer, which had some significance in the differentiation of cancer and non-cancerous lesions.