Recent Treatment Options for Primary Colonic Leiomyosarcoma: A Case Report and a Review of the Literature

Primary colonic leiomyosarcoma (LMS) accounts for only 0.12% of colonic malignancies. However, it is highly aggressive and associated with a poor prognosis. While radical surgical resection is considered the mainstay of treatment, the optimal surgical approach and the role of adjuvant chemotherapy remain unclear due to the small number of reported cases.

A 45-year-old, male patient presented with hematochezia. Colonoscopy revealed a 40-mm, type 1 tumor in the sigmoid colon. Immunohistochemical analysis of a biopsy specimen found atypical spindle cell proliferation, positivity for desmin and h-caldesmon, and negativity for CK AE1/AE3, indicating smooth muscle differentiation. Contrast-enhanced CT demonstrated a 40-mm, enhancing mass without a lymph node or distant metastasis. The patient underwent a laparoscopic sigmoidectomy with lymph node dissection. Pathological examination confirmed a 40 × 42 × 35 mm, French Federation of Cancer Centers (FNCLCC) grade 2 leiomyosarcoma with partial serosal exposure, negative margins, and no nodal involvement (0/42). Immunohistochemistry revealed positivity for α-SMA, desmin, h-caldesmon, and calponin, with a Ki-67 index of 60%-80%. Postoperatively, the patient received six cycles of adjuvant chemotherapy with doxorubicin and ifosfamide. A follow-up examination at 3 years and 6 months found no recurrence.

This report underscores the potential efficacy of minimally invasive surgery and adjuvant chemotherapy in some patients with primary colonic LMS, which in the present case was successfully managed with laparoscopic resection followed by adjuvant chemotherapy. More evidence is needed to establish a standard treatment strategy.