Low-grade myofibroblastic sarcoma of the orbit in an elderly patient: a case report

Low-grade myofibroblastic sarcoma (LGMS) is an extremely rare malignant tumor of myoblastic origin. To date, five confirmed cases of ocular low-grade myofibroblastic sarcoma (LGMS) have been documented in the available literature, including four orbital cases and one limbal case. The ages of these patients ranged from 10 months to 48 years, and no cases in elderly patients have been previously reported. This is the first report of orbital LGMS in an elderly patient, a 79-year-old female, with severe pain in the right eye as the main clinical manifestation. Under the microscope, there were spindle tumor cells arranged in fascicles; the nuclei showed mild to moderate atypia, and there were many different collagen fibers between the cells. The patient underwent surgical resection of the tumor. The postoperative immunohistochemical results showed that the patient’s specimen was immunopositive for smooth muscle actin (SMA), Vimentin, and calponin, and immunonegative for Desmin, S-100, and CD34, which confirmed the diagnosis of LGMS. At present, unified diagnostic criteria and a standardized diagnostic and treatment scheme for this rare tumor have not been established, and this remains a difficult problem in the clinic. Therefore, an in-depth understanding of the disease characteristics of orbital LGMS in older patients is of great significance for early diagnosis and for deepening knowledge of the disease.