Low-Grade Myofibroblastic Sarcoma of the Oral Cavity: A Report of Three Cases Illustrating an Emerging Disease in Children

Abstract

Low-grade myofibroblastic sarcoma (LGMS) is a mesenchymal tumor of myofibroblasts that occurs more frequently in adults. A series of three cases is presented to illustrate that LGMS may also occur within the oral cavity in children and adolescents. The first case (Case 1) occurred intra-osseously in the mandible, while the remaining two presented as gingival swellings and were purely restricted to soft tissue (Cases 2 and 3). The intra-osseous lesion arose in a 7-year-old girl, whereas the gingival lesions were observed in a 12-year-old girl (Case 2) and a 13-year-old boy (Case 3). Histopathologically, all cases were composed of spindle shaped cells arranged into long fascicles showing mild to moderate degree of nuclear atypia. Ki-67 (MIB-1) proliferation activity was relatively low, amounting to 3–5% in all cases. Immunohistochemically, all cases showed smooth muscle actin (SMA) positivity in spindle cells, while desmin, beta catenin, cytokeratin, and CD34 were negative, resulting in a diagnosis of LGMS. In conclusion, current series of three cases of LGMSs that occurred in the oral cavity in a child and two adolescent patients is presented to highlight an emerging disease that requires additional data for further characterization.

Case report: Low-grade myofibroblastic sarcoma resembling lymphoma on 18F-FDG PET/CT

“…The immunohistochemistry staining of SMA and Vimentin was positive in our case. LGMS mainly involves the head and neck, particularly the oral cavity and tongue (1)(2)(3)(4). can be observed in the muscle, breast, and pleura in addition to a few individual case reports (5-10).…”

“…LGMS mainly involves the head and neck, particularly the oral cavity and tongue ( 1 – 4 ). LGMS can be observed in the bone, muscle, breast, and pleura in addition to a few individual case reports ( 5 – 10 ).…”

Low-grade myofibroblastic sarcoma of the mandible: A rare tumour of childhood

“…A recent literature review by Jayasooriya et al [ 11 ] described 33 cases of low-grade myofibroblastic sarcoma that purely involved the oral cavity. The patients had an age range of 7–74 years with a bimodal age distribution.…”

Recurrent periorbital low-grade myofibroblastic sarcoma in an infant

“…LMFS are rare in pediatric age group and even rarer in first decade of life; approximately, 10 cases of LMFS have been reported in the first decade of life but none in infancy (present case at the age of 1 month). [ 2 ] Although 2 case reports of LMFS are available in ophthalmic literature, 1 in orbit and another at limbus, respectively, none avaialble in the periorbital region. [ 3 4 ]…”

“…LGMF sarcomas arising from bone show osteolytic and rarely osteoblastic changes along with the mass lesion. [ 2 3 ]…”