Surgical treatment and long-term outcomes of low-grade myofibroblastic sarcoma: a single-center case series of 15 patients

Abstract

Background: Low-grade myofibroblastic sarcoma (LGMS) is a poorly studied, rare, soft tissue sarcoma. LGMS is characterized by a low malignancy potential, tendency for local recurrence, and low likelihood of distant metastases. However, no studies have reported on the surgical treatment method and its long-term outcomes.

Methods: We included all patients treated for LGMS at our institution between March 2010 and March 2021. Medical charts were retrospectively reviewed to collect demographic information, as well as information about the clinical course, tumor characteristics, and outcomes. Statistical analysis was performed to identify the factors associated with the recurrence rate.

Results: Fifteen patients who underwent surgical treatment were enrolled in this study. There were seven cases in the upper extremities, four in the trunk area, three in the lower extremities, and one in the head and neck area. There were no metastatic cases and two cases of local recurrence.

Conclusions: The incidence of LGMS in the extremities or trunk may be higher than expected based on the current literature. Univariate analysis showed that local tissue invasion and surgical method could be associated with local recurrence. Although further large studies are needed to establish risk factors of local recurrence or extent of resection margins, based on our study, wide local excision under the proper diagnosis is the most important treatment.

Fig. 1

Physical examination revealed a tender mass in upper abdomen, approximately 4 × 4 cm in size

Fig. 2

MRI showed a lobulated mass (4.1 × 3.8 × 4.8 cm) in the left paramedian anterior chest wall. MRI revealed the invasion of rectus abdominis muscle (red arrow)

Fig. 3

X-ray revealed a bony defect of right third proximal phalanx (red arrow)

Fig. 4

MRI of the finger confirmed the presence of a mass (1.9 × 1.8 × 1.9 cm) encircling the third flexor digitorum tendon, and bony invasion was observed. A Axial view (T2-weighted image). B Sagittal view (T1-weighted, fat suppressed image)

Fig. 5

Histopathologic finding. A Hematoxylin and eosin staining (× 40) showing hypercellular areas with a proliferation of spindle cells. B Hematoxylin and Eosin staining (x100) showing interlacing fascicles of spindle shaped tumor cells. C Immunohistochemistry showing positive staining for smooth muscle actin. D Positivity for Ki-67 staining was noted in more than 10% of the tumor cells