Low-Grade Myofibroblastic Sarcoma of the Tongue: Case Report and Review of Literature

Introduction: Low-grade myofibroblastic sarcoma (LGMS) is one of the ultra-rare malignant soft tissue tumors, with an annual incidence of less than 1 per 1,000,000. However, due to its rarity, there is currently no standardized treatment guideline. The therapeutic approaches remain under investigation with the ongoing accumulation of clinical experience. Case Report: A 55-year-old female with no significant medical history presented with a two-week history of a tongue mass and associated numbness. Physical examination revealed a 1.4 cm, firm, non-tender lesion on the ventral surface of the tongue. An excisional biopsy was performed, and the tumor was identified as an LGMS, characterized by spindle-shaped cells infiltrating adjacent skeletal muscle. Immunohistochemistry showed positive staining for α-SMA and negative results for desmin, cytokeratin, P63, CD34, S100, and Ki67. A PET-CT scan revealed focal FDG uptake in the tongue, likely related to postoperative changes, with no distant metastasis. The clinical stage was T1N0M0. In this report, a review of the literature was conducted, summarizing the interpretation of immunohistochemistry and discussing relevant studies on the treatment of LGMS. Conclusion: LGMS should be considered in the differential diagnosis of tongue tumors, with biopsy being crucial for confirming the diagnosis. Due to its rarity, there are no standardized treatment protocols, but surgical excision remains the primary approach. Given the risk of recurrence, regular follow-up is recommended.