Background: Mesenteric Leiomyosarcoma (LMS) is a rare soft tissue tumor that takes its origin from smooth muscle cells, usually mesenteric blood vessels. Immunohistochemical (IHC) staining is deemed necessary for the diagnosis. Surgical resection with negative microscopic margins is the best treatment available, with limited role of chemo and radiotherapy. Case Presentation: We present a case of 46-year-old male who presented with large abdominal mass and obstructive symptoms. Surgical excision was performed and diagnosis of LMS was established on the basis of IHC stains. Currently, the patient is under follow up and has not developed any recurrence. Conclusion: Due to limited cases recorded globally, definitive guidelines for the management of this tumor are lacking. Work needs to be done to explore further about Primary Mesenteric LMS.

Keywords: Leiomyosarcoma, biopsy, large core-needle, mesenchymal tumor, case report.