Leiomyosarcoma are rare tumors of small intestine which arise from the muscularis mucosa or muscularis propria. The most common site of LMS in the small intestine is jejunum followed by ileum and then duodenum. The common presentations include abdominal mass, abdominal pain or overt gastrointestinal bleeding. They are mainly seen in 6th decade of life with slight male preponderance. Preoperative diagnosis of small intestinal tumors is difficult, especially differentiating between benign and malignant tumors. For LMS in small intestine, recent review of literature revealed that CT and MRI-enterography and enteroclysis are good options.Cases of superficial lesion which can be missed by both CT and MRI, can however be detected by water capsule endoscopy with a detection rate of around 80%. Histologically LMS resembles like GIST, however they are CD117 and CD34 negative by immunohistochemistry and positive for smooth muscle antigen (SMA) and desmin. When these tumors are more than 5 cm they commonly spread hematogenously to liver (65%), other GI organs (15%), lung(4%). It also has the capability to spread via lymphatics (13%) or via peritoneal route (18%). The only effective treatment for small intestine LMS is surgery. The primary tumor should be excised radically, including a wide resection of the mesentry. Response to chemotherapy is doubtful, and there is no role for radiotherapy. Therefore, metastasectomy, if possible, should be considered. Large phase II and III studies combining docetaxel and gemcitabine yielded impressive response rates in LMSs (mostly of uterine origin). However, others were not able to confirm the efficacy of this combination. Recently, trabectedin showed response rates up to 56% in LMSs, and it appeared to be especially useful in far-advanced and metastatic LMSs after failure of the combination of anthracyclines and ifosfamide.
Leiomyosarcoma (LMS) is a rare small intestinal tumor, which arises from the muscularis mucosa or muscularis propria . The most common site of occurrence of LMS in the small intestine is the jejunum, followed by the ileum and duodenum. Its common manifestations include abdominal mass, abdominal pain, and overt gastrointestinal bleeding.. They are mainly observed in the 6th decade of life, with slight male preponderance. In general, the preoperative diagnosis of small intestinal tumors such as LMSs is difficult, especially in terms of differentiating between benign and malignant tumors. According to a recent literature review computed tomography (CT) and magnetic resonance (MR) enterography and enteroclysis are good modalities for the assessment of LMS. Superficial lesions, which can be missed by both CT and MR imaging, can be detected by water capsule endoscopy, with a detection rate of approximately 80%. Histologically, LMS resembles gastrointestinal stromal tumor; however, on immunohistochemical analysis, it has been found to be negative for CD117 and CD34 and positive for smooth muscle actin and desmin. When the size of LMS is more than 5 cm, it can hematogenously spread to the liver (65%), other gastrointestinal organs (15%), and the lungs (4%). It can also spread via the lymphatic system (13%) or peritoneal route (18%). The response of LMS to chemotherapy is unknown, and radiotherapy does not play a role in the treatment. Therefore, surgery is the only effective treatment for LMS in the small intestine. The primary tumor should be excised radically with wide resection of the mesentery. If possible, metastasectomy should be considered. Large phase II and III trials involving the combination of docetaxel and gemcitabine have reported impressive response rates for LMSs (mostly of uterine origin). However, some studies have not been able to confirm the efficacy of this combination. Trabectedin has recently showed response rates of up to 56% for LMSs, and it appeared to be particularly useful against far-advanced and metastatic LMSs after failure of anthracyclines and ifosfamide combination therapy.