Atypical anorectal malignant melanoma: case report and literature review
Li Peng
ZHONG Jin
LIU Jun
Abstract：Objective To evaluate the MR findings and pathological features, differential diagnosis of atypical anorectal malignant melanoma. Methods A case of anorectal malignant melanoma proved by histology was retrospectively analysed, and related literatures were reviewed. Results MRI scan revealed a round-like solid mass in the anorectal junction area which showed slightly long T1 and long T2 signal intensity, well-defined and relatively homogenous. The size of the mass was about 3.3 cm×4.2 cm×4.3 cm. Some nodules and masses were found in the mesorectal area and outside fascia, and the largest one was about 3.2 cm ×2.5 cm ×3.8 cm. Intraoperative observation showed that the tumor was solid, the boundary was clear, and the surface was smooth. Pathological diagnosis:malignant melanoma tumor. Immunohistochemistry showed HMB45 and Melan-A were positive, suggesting melanoma tumor. Conclusion Anorectal malignant melanoma is rare and usually does not have specific clinical and imaging manifestation. Accurate diagnosis depends on the pathological and immunohistochemical examination.
Keywords：MelanomaAnorectal junctionMagnetic resonance imaging
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 175-178 )