https://orcid.org/0009-0001-1200-6974
Abstract
Myofibrosarcoma is a rare spindle-cell malignancy with myofibroblastic differentiation, and primary maxillary sinus involvement is exceptional. A 36-year-old woman presented with progressive unilateral nasal obstruction, purulent rhinorrhea, and hemifacial pain. Computed tomography and magnetic resonance imaging demonstrated a destructive 44 × 45 × 57 mm right maxillary sinus mass involving the orbital floor and extending into the nasal cavity, ethmoid cells, and pterygopalatine fossa. Histology and immunohistochemistry supported the diagnosis of myofibrosarcoma. Partial maxillectomy with titanium orbital floor reconstruction was performed. Several soft-tissue margins were positive, whereas gingival and bony margins were clear. Postoperative radiotherapy delivered 66 Gy in 33 fractions. This case illustrates the diagnostic complexity of sinonasal spindle-cell tumors and the individualized role of radiotherapy when local control is threatened by anatomically constrained positive-margin disease.
Introduction
Myofibrosarcoma is a rare malignant mesenchymal tumor composed of spindle cells showing myofibroblastic differentiation [1–3]. The World Health Organization classification specifically recognizes low-grade myofibroblastic sarcoma [1, 4]; this terminology is not used interchangeably here with the definitive histological diagnosis of myofibrosarcoma in the present case. Primary nasal cavity and paranasal sinus involvement is uncommon, and maxillary sinus cases are limited to isolated reports and small series [5–12]. We report a locally advanced right maxillary sinus myofibrosarcoma with orbital floor involvement, positive soft-tissue margins, and postoperative radiotherapy.
Case report
A 36-year-old woman with no relevant medical history presented with 3 months of progressive right-sided nasal obstruction, purulent rhinorrhea, and hemifacial pain. Nasal endoscopy showed a tumor occupying the right nasal cavity, without clinically evident cervical lymphadenopathy.
Contrast-enhanced computed tomography (CT) demonstrated a 44 × 45 × 57 mm heterogeneous mass centered on the right maxillary sinus. It eroded the sinus walls and orbital floor, extended into the nasal cavity and ethmoid cells, filled the pterygopalatine fossa, and destroyed the superior maxillary alveolar bone (Fig. 2). Magnetic resonance imaging (MRI) confirmed extension toward the premaxillary tissues, buccal fat pad, pterygoid region, zygomatic bone, and ethmoid cells, with displacement of the orbital floor and inferior rectus muscle but no definite deep intraconal or intracranial invasion (Fig. 3).
Endoscopic biopsy showed a malignant fascicular spindle-cell proliferation with moderate atypia and a slightly myxoid stroma. Tumor cells expressed smooth muscle actin and calponin, with focal h-caldesmon expression, and were negative for the pancytokeratin AE1/AE3 antibody cocktail, desmin, S100, cluster of differentiation 34 (CD34), and signal transducer and activator of transcription 6 (STAT6). The Ki-67 index was ~40%, indicating high proliferative activity. The histomorphological and immunohistochemical findings supported the diagnosis of myofibrosarcoma (Fig. 4).
Following multidisciplinary review, partial maxillectomy was performed. The orbital floor was reconstructed with a titanium plate, allowing orbital preservation (Fig. 1). Definitive histology confirmed a 5-cm myofibrosarcoma. The superior, posterior, lateral, and fibrous soft-tissue margins were involved, while gingival and bony margins were clear.
Clinical, intraoperative, and postoperative findings; (A) preoperative frontal view showing right midfacial swelling; (B) intraoperative view during partial maxillectomy; (C) gross surgical specimen after tumor resection; (D) postoperative appearance following partial maxillectomy and orbital floor reconstruction.
Contrast-enhanced CT of the paranasal sinuses; (A) coronal image showing a destructive right maxillary sinus mass with orbital floor erosion and superior extension toward the orbit; (B) axial image demonstrating extension into the right nasal cavity and pterygopalatine fossa; arrows indicate the tumor and areas of extension.
MRI of the right maxillary sinus tumor; (A) coronal image demonstrating superior extension toward the orbital floor; (B) axial image showing the tumor and its relationship with adjacent deep facial spaces; arrows indicate the lesion.
Histopathological and immunohistochemical findings; (A) hematoxylin and eosin staining (original magnification ×40) showing fascicles of atypical spindle cells in a slightly myxoid stroma; (B) smooth muscle actin positivity; (C) calponin positivity; (D) Ki-67 nuclear labeling in ~40% of tumor cells.
Given the locally advanced site, orbital floor involvement, high proliferative index, and positive soft-tissue margins, postoperative radiotherapy delivered 66 Gy in 33 fractions. A transient decrease in right visual acuity resolved within 1 month. At 6 months, the patient was clinically well without evident local recurrence; continued clinical and radiological surveillance is ongoing.
Discussion
Sinonasal myofibrosarcoma is diagnostically challenging because spindle-cell carcinoma, leiomyosarcoma, malignant peripheral nerve sheath tumor, melanoma, solitary fibrous tumor, inflammatory myofibroblastic tumor, and biphenotypic sinonasal sarcoma may show overlapping morphology [13]. In this case, the combined expression profile supported myofibroblastic differentiation, while negative epithelial, neural, and fibroblastic markers argued against major alternatives. Molecular testing was unavailable, limiting complete exclusion of molecularly defined mimics.
Surgery with negative margins remains the treatment cornerstone. However, the orbit, skull base, palate, pterygopalatine fossa, infraorbital nerve, and masticator space frequently restrict wide sinonasal resection. Published maxillary and sinonasal cases demonstrate heterogeneous treatment and outcomes (Table 1). In our patient, partial maxillectomy achieved macroscopic removal and orbital preservation but left multiple positive soft-tissue margins.
Clinicopathological features of reported maxillary sinus and sinonasal myofibrosarcoma cases
| Author, year | Age/sex | Site/side | Reported grade | Size | Presentation | Treatment | Outcome |
|---|---|---|---|---|---|---|---|
| Bisceglia et al., 2001 [7] | 24/M | Left maxilla | Low-grade | 4 cm | Pain and midface swelling | Surgery; details not reported | No recurrence; follow-up 40 months |
| Meng et al., 2007, case 1 [6] | 33/F | Left sinonasal region | Intermediate | 6.5 cm | Nasal obstruction and rhinorrhea | Wide excision by Caldwell–Luc approach + RT 60 Gy | Died of disease; follow-up 12 months |
| Meng et al., 2007, case 6 [6] | 28/F | Left sinonasal region | Intermediate | 4 cm | Nasal obstruction and rhinorrhea | Wide excision by Caldwell–Luc approach | Local recurrence at ~6 months; follow-up 21 months |
| Gangwar et al., 2015 [8] | 27/M | Maxilla | Reported as myofibrosarcoma/LGMS | 6 × 5 cm | Not reported | Total maxillectomy + RT | No recurrence; follow-up 24 months |
| Gomez-Oliveira et al., 2015 [9] | 75/F | Left maxillary sinus | Low-grade | Not reported | Pain, swelling, destructive mass | Maxillectomy + orbital floor reconstruction + free flap + adjuvant RT | Distant metastasis reported at ~1 year |
| Ghosh et al., 2019 [10] | 35/M | Right maxillary sinus | Low-grade | Not reported | Exophthalmos | Extended medial maxillectomy ± chemotherapy, as reported | Local recurrence at ~6 years |
| Mydlak et al., 2024, case 1 [11] | 46/M | Right maxillary sinus | Low-grade | 8 cm | Pain, midface swelling, nasal obstruction | Expanded maxillectomy + reconstruction + IMRT 66 Gy | No recurrence; follow-up 15–18 months |
| Mydlak et al., 2024, case 2 [11] | 45/M | Right maxillary sinus | Low-grade | 8 cm | Exophthalmos, diplopia, visual impairment | Expanded surgery + adjuvant RT; later palliative chemotherapy | Recurrence and death; follow-up 26 months |
| Dabas et al., 2024 [12] | 39/M | Left maxilla | Myofibrosarcoma | 4.8 × 1.7 × 4.2 cm | Epistaxis, nasal obstruction, visual loss | Maxillectomy + reconstruction + adjuvant RT | Disease-free at 3 years |
| Present case | 36/F | Right maxillary sinus | Descriptively intermediate-grade | 5 cm on pathology | Hemifacial pain, nasal obstruction, nasal cavity mass | Partial maxillectomy + orbital floor reconstruction + postoperative RT 66 Gy/33 fractions | Transient visual acuity decrease with full recovery; favorable 6-month clinical follow-up |
Abbreviations: F, female; Gy, gray; IMRT, intensity-modulated radiotherapy; LGMS, low-grade myofibroblastic sarcoma; M, male; RT, radiotherapy.
This table provides a comparative summary of the clinicopathological features, treatments, and outcomes of previously reported maxillary sinus and sinonasal myofibrosarcoma cases.
Terminology and histological grading are reported as described in the original publications.
Most available evidence regarding radiotherapy concerns low-grade myofibroblastic sarcoma rather than myofibrosarcoma. Population data in low-grade myofibroblastic sarcoma have not shown a clear survival benefit in unselected patients, but available studies incompletely account for margin status and local anatomical constraints [5, 14, 15]. These data should therefore be interpreted cautiously when extrapolated to the present case. Radiotherapy may be considered when local control is threatened by positive margins, recurrence, locally advanced disease, or a constrained head and neck location. The principal limitations of this report are the absence of molecular testing and short follow-up.
This case emphasizes the need for radiological, pathological, and surgical correlation in destructive maxillary sinus spindle-cell tumors. Complete excision should be pursued, while postoperative radiotherapy may be individualized for high-risk positive-margin disease. Long-term surveillance is essential.
Reporting guideline
This case report was prepared in accordance with the CAse REport (CARE) guidelines.
Author contributions
The authors contributed to the conceptualization, data collection, investigation, formal analysis, supervision, validation, drafting, and critical revision of the manuscript. All authors reviewed and approved the final manuscript.
Conflicts of interest
The authors declare no conflicts of interest.
Funding
The authors received no financial support for the research, authorship, or publication of this article.
Data availability
Clinical data are not publicly available because of patient confidentiality but may be available from the corresponding author upon reasonable request and subject to ethical and legal restrictions.
Ethical approval
Ethical approval was not required for this single anonymized case report according to local institutional policy.
Patient consent
Written informed consent was obtained from the patient for publication of the anonymized clinical information and all accompanying images. The signed consent form is retained securely by the treating institution and is available to the Editor upon confidential request.
