Imaging Diagnosis of Anorectal Malignant Melanoma :A Report of 5 Cases with Literature Review
- VernacularTitle:原发性肛管直肠恶性黑色素瘤影像学诊断(5例报告及文献复习)
- Author:
Shengxiang RAO
;
Dongqing WANG
;
Renchen LI
;
Caizhong CHEN
;
Mengsu ZENG
- Publication Type:Journal Article
- Keywords:
anus;
rectum;
melanoma;
tomography,X-ray computed;
MRI
- From:
Journal of Practical Radiology
1996;0(04):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To discuss the diagnostic value of CT and MRI for primary anorectal malignant melanoma(AMM).Methods 5 patients(2 males and 3 females)with AMM confirmed pathologically were analyzed retrospectively,which were examined by CT(n=4)and 1.5T MRI(n=1).Results AMM presented as bulky intraluminal fungating masses without intestinal obstruction(n=4)and irregular rectal wall thickening(n=1).2 cases had perirectal fat infiltration and extended to the presacral space in one case,4 cases had perirectal enlarged lymph nodes and larger than 3 cm in diameter in one case.Nonenhanced CT showed a hypodense lesion and contrast-enhanced CT showed slight enhancement(n=1)and mild enhancement(n=3).The tumor scanned by MRI depicted high intensity on T1WI and low intensity on T2WI,so did the enlarged lymph nodes and bone metastasis.Fat-saturation T1WI significantly improved the extention of tumor and detection of metastasis.Conclusion Bulky intraluminal fungating masses without intestinal obstruction,perirectal fat infiltration and enlarged lymph nodes may be helpful to diagnose AMM.MRI is especially useful in differentiating melanotic AMM from other rectal tumors.
