A rare low-grade myofibroblastic sarcoma in lower jaw with the resemblance to benign lesions

Oral and Maxillofacial Low-Grade Myofibroblastic Sarcoma: A Systematic Review

BACKGROUND

This systematic review (SR) aimed to summarize the clinical, histopathological, and immunohistochemical features of low-grade myofibroblastic sarcoma (LGMS) in the oral and maxillofacial region (OMR), as well as treatment protocols, recurrence, follow-up, and metastasis rates. It follows PRISMA 2022 guidelines and is registered in PROSPERO (CRD42023409758).

METHODS

An electronic search included PubMed, EMBASE, Scopus, Web of Science, LILACS, Google Scholar, and ProQuest databases, and bias risk was assessed using the Joanna Briggs Institute tool. Statistical analyses, including Fisher's and Chi-Squared tests, were conducted to explore associations between clinical variables, and survival analysis was performed using the Kaplan-Meier method.

RESULTS

Forty-three studies covering 78 cases were included. LGMS showed a slight female predominance (51.28%) and an average patient age of 35.35 years. The most affected sites were the mandible (29.4%), maxilla (19.23%), and tongue (15.38%). Clinical presentations included masses (30.76%), tumors (26.92%), and swelling (12.82%), with symptom duration ranging from 1 week to 30 months. Surgery alone was the primary treatment (60.25%), with recurrence in 20.51% and metastasis in 5.12% of cases. One-year and 5-year overall survival rates were 92.6% and 71.8%, respectively. Surgery as the sole treatment was significantly associated with a lower metastasis rate (p = 0.005).

CONCLUSION

Our findings highlighted the importance of considering LGMS in differential diagnoses of myofibroblastic lesions and underscored the need for a comprehensive immunohistochemical analysis. Complete surgical excision remains the preferred treatment, though long-term follow-up is needed to better understand recurrence and metastasis risks.

Indolent growth of low‑grade myofibroblastic sarcoma of the knee with the resemblance of a benign lesion: A case report

Low-grade myofibroblastic sarcoma (LGMS) is a rare soft-tissue malignant neoplasm originating from the stromal cells that is predominantly comprised of atypical myofibroblasts. The present study reports the case of a patient with low-grade myofibroblastic sarcoma in the soft tissue of the knee. The patient exhibited a soft, painless mass on the medial side of the left knee. During surgery, a yellow-white mass above the posterior margin of the sartorius muscle was identified. This mass, which was irregular and adherent to surrounding tissues, had a blurry boundary, indicative of invasive growth. The morphology of the mass significantly differed from conventional lipomas and was lacking typical features. Immunohistochemical staining confirmed the diagnosis of a malignant LGMS. The patient experienced no recurrence over 1 year of follow-up and reported complete recovery of knee range of motion. The present study suggests that an incisional biopsy may be performed if LGMS is suspected based on patient symptoms and imaging results. In addition, long-term follow-up is crucial for the timely detection and management of any recurrence, playing a key role in the patient's ongoing care and treatment.

Low-Grade Myofibroblastic Sarcoma of the Oral and Maxillofacial Region: An International Clinicopathologic Study of 13 Cases and Literature Review

Low-grade myofibroblastic sarcoma (LGMS) represents an atypical tumor composed of myofibroblasts with a variety of histological patterns and with a high tendency to local recurrence and a low probability of distant metastases. LGMS has predilection for the head and neck regions, especially the oral cavity. This study aimed to report 13 new cases of LGMS arising in the oral and maxillofacial region. This study included LGMS cases from five oral and maxillofacial pathology laboratories in four different countries (Brazil, Peru, Guatemala, and South Africa). Their clinical, radiographic, histopathological, and immunohistochemical findings were evaluated. In this current international case series, most patients were females with a mean age of 38.7 years, and commonly presenting a nodular lesion in maxilla. Microscopically, all cases showed a neoplasm formed by oval to spindle cells in a fibrous stroma with myxoid and dense areas, some atypical mitoses, and prominent nucleoli. The immunohistochemical panel showed positivity for smooth muscle actin (12 of 13 cases), HHF35 (2 of 4 cases), β-catenin (3 of 5 cases), desmin (3 of 11 cases), and Ki-67 (range from 5 to 50%). H-caldesmon was negative for all cases. The diagnosis of LGMS was confirmed in all cases. LGMS shows predominance in young adults, with a slight predilection for the female sex, and maxillary region. LGMS should be a differential diagnosis of myofibroblastic lesions that show a proliferation of spindle cells in a fibrous stroma with myxoid and dense areas and some atypical mitoses, supporting the diagnosis with a complementary immunohistochemical study. Complete surgical excision with clear margins is the treatment of choice. However, long-term follow-up information is required before definitive conclusions can be drawn regarding the incidence of recurrence and the possibility of metastasis.

Low-grade malignant myofibroblastic sarcoma of the larynx: a case report

Low-grade myofibroblastic sarcoma (LGMS) is a rare malignant mesenchymal tumor derived from myofibroblasts. It is commonly identified in the head and neck, and particularly in the oral cavity, but rarely in the larynx. In this case report, we describe a patient who presented with hoarseness and underwent electronic fiber laryngoscopy, which revealed a neoplasm on the surface of his left vocal cord. The vocal cord tumor was resected under general anesthesia, and a malignant LGMS was diagnosed on postoperative pathologic examination. The results of immunohistochemical staining of the sections for vimentin (diffuse +), actin (partial +), and desmin (-) were consistent with this diagnosis. The patient recovered well after the surgery, and there was no recurrence of the neoplasm.