| Theme |
Diagnosis and Treatment of Anorectal Disease |
| Title |
Non-epithelial Malignant Tumors -- GIST, Melanoma and Lymphoma |
| Author |
Ryo Inada |
Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences |
| Author |
Shin Fujita |
Division of Colorectal Surgery, Tochigi Cancer Center |
| Author |
Hirokazu Taniguchi |
Pathology and Clinical Laboratory Division, National Cancer Center Hospital |
| Author |
Futoshi Uno |
Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences |
| Author |
Takeshi Nagasaka |
Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences |
| Author |
Toshiyoshi Fujiwara |
Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences |
| [ Summary ] |
Non-epithelial tumors, such as gastrointestinal stromal tumors (GIST), malignant melanoma and malignant lymphoma, are uncommon compared to adenocarcinoma or squamous cell carcinoma among anorectal malignant tumors. Although they often take the form of submucosal tumors, they follow different clinical courses. GIST arises from interstitial cells of Cajal driven by mutations of the KIT or PDGFRA genes. Only complete surgical resection can produce cures. However, imatinib is indicated for clinical treatment of unresectable advanced GIST. Anorectal malignant melanoma arises from melanocytes near the dentate line and is seldom observed. Amelanotic leisions are occasionally observed. The malignancy potential of anorectal melanoma is extremely high. However an efficient treatment has not been established. Extranodal malignant lymphoma in the gastrointestinal tract infrequently arises in the lower rectum as compared to the stomach, small intestine or cecum. Most types of extranodal malignant lymphoma of the rectum consist of diffuse large B-cell lymphoma (DLBCL) or mucosa-associated lymphoid tissue (MALT) lymphoma. The standard treatment for localized malignant lymphoma is radical resection. Extended malignant lymphoma is treated with systematic chemotherapy. In this manuscript, we explain the diagnosis and treatment of anorectal non-epithelial malignant tumors. |