The challenging diagnosis of low-grade myofibroblastic sarcoma: A case report and literature update.

Low-Grade Myofibroblastic sarcoma (LGMS) is categorized as an extremely rare malignant neoplasia of myofibroblasts, which has only recently become more widely studied. Our patient was referred for evaluation of a nodule involving the palate. The histopathological analysis showed a mesenchymal tumor formed for stellate-shaped cells. Negativity for Laminin, Desmin, Collagen IV, CK pool, CD34, S100, and ALK1, discarded epithelial, endothelial, neural, and inflammatory origin. On the other hand, the positivity for Calponin and SMA demonstrated myofibroblastic and smooth muscle differentiation. The diagnosis of LGMS was endorsed and the patient was submitted for medical treatment. To date, only 18 cases describing patients diagnosed with intrabuccal LGMS have been reported in the scientific literature. Here, we introduce a rare report and for the first time, also provide an update of the literature and a clear review regarding the immunohistochemical panel to diagnose this entity, once the histopathological diagnosis is still challenging.