Combined Lynch Incision (Transfacial Medial Orbitotomy) and Endoscopic Endonasal Approach for Atypical Solitary Fibrous Tumor Involving the Orbitonasal Junction With an 18-Year Course of Four Recurrences: A Case Report

1. Surgical Method

A combined endoscopic endonasal and transfacial approach was performed. The procedure consisted of three components: (1)endoscopic anterior ethmoidectomy to expose the tumor extending from the orbit into the ethmoid sinus; (2)left facial Lynch incision combined with a supraorbital incision to access the orbit and maxillary sinus; (3)en bloc resection of the orbitonasal tumor, including the involved nasolacrimal duct and bone margins, followed by orbital reconstruction.

2. Surgical Procedure

Nasal mucosa was decongested with adrenaline-soaked cottonoids.Under 0° endoscopy, the left anterior ethmoid cells were opened, revealing tumor herniation from the inferomedial orbital wall into the ethmoid sinus with compression of the nasofrontal duct. The sinus ostium was widened, secretions were suctioned, and the cavity was temporarily packed.

A left Lynch incision combined with a supraorbital incision was then made. The skin incision extended from 5 mm below the orbital floor along the left nasal sidewall, around the ala to the nasolabial fold and columella, then through the upper lip and gingivolabial mucosa to the first molar. The superior limb was extended along the brow to the lateral canthus. The facial flap was elevated to expose the orbital rim and anterior maxillary wall (Figure 2A).OPEN IN VIEWER

The orbit was occupied by a lobulated, ill-defined mass; the left globe had been previously enucleated. The anterior medial orbital wall was destroyed, creating a direct communication with the nasal cavity, and the nasolacrimal duct was dilated (Figure 2B). The tumor was dissected bluntly along the orbital walls. The superior wall was intact. On the lateral wall, titanium plates and screws from prior surgery were removed due to fibrous adhesion. The medial wall showed bone destruction involving the anterior ethmoid cells and the nasolacrimal duct, with tumor extension into the maxillary sinus. The infraorbital wall was partially eroded. The involved nasolacrimal duct and intranasal tumor components were completely excised. Irregular bone along the orbital walls was drilled to healthy margins (Figure 2C). The orbit was reconstructed and closed in layers. Estimated blood loss was 150 mL.

3. Postoperative Outcome

Histopathological examination of the resected specimen (5.0 × 6.5 cm) confirmed an atypical solitary fibrous tumor with focal malignant transformation (Figure 3A), showing high cellularity, nuclear atypia, mitotic count >4/HPF (up to 10/HPF in hotspots), and foci of necrosis and hemorrhage. Immunohistochemistry was positive for STAT6, CD34, CD99, Bcl-2, and vimentin, with a Ki-67 index of 20%, and negative for CK, SMA, desmin, and S-100. The wound healed primarily (Figure 3B and C). Facial nerve function was House-Brackmann grade I. The patient remains under close surveillance. During the short-term follow-up period of 8 months post-surgery, MRI and nasal endoscopy showed no overt signs of recurrence or metastasis(Figure 4).OPEN IN VIEWER

OPEN IN VIEWER

Figure 4.

Follow-up assessment: Head MRI performed at 2 months after discharge(4A); Skin incision healing at 5 months after discharge(4B);Nasal endoscopic view(4C).

1. Long-Standing SFT With Four Recurrences: The Critical Role of Early Pathological Diagnosis

SFTs exhibit unpredictable behavior: most follow an indolent course, but a subset shows aggressive features (local infiltration, recurrence, and even malignant transformation with metastatic potential). ⁴ Compounding this challenge, recurrences can occur after prolonged latency—sometimes decades post-resection—with reported intervals of 6–15 years. ⁵ The present case is particularly instructive in this regard. Our patient underwent four recurrences over an 18-year course, with the first three surgeries performed at outside hospitals without histopathological examination. This delay in diagnosis meant that the tumor’s true nature—and its progressive evolution toward malignancy—remained unrecognized for nearly two decades. When the tumor was finally diagnosed as atypical SFT in 2020 after enucleation, it had already exhibited histological features of malignant transformation, including high cellularity, significant nuclear atypia, mitotic activity up to 10/HPF, foci of necrosis, and a Ki-67 index of 20%. What makes this case particularly instructive is the sheer length of the diagnostic odyssey—18 years from first presentation to definitive histology. The lesson is not merely academic: a recurrent mass in this region, even if it appears indolent or has been previously resected without complication, should prompt immediate histopathological evaluation with immunohistochemistry. Waiting for recurrence, as happened here, risks missing the window for less morbid surgery and allows potential malignant transformation to proceed unchecked.

2. Anatomic Challenges at the Orbitonasal Junction

The orbitonasal junction is anatomically complex, with the orbit communicating with the nasal cavity and paranasal sinuses via the nasolacrimal canal, ethmoidal air cells through the lamina papyracea, and the inferior orbital fissure. The lamina papyracea is exceptionally thin and fenestrated, offering minimal resistance to tumor spread. ⁶ This vulnerability explains why orbitonasal communicating tumors, though comprising only 2.0% of primary orbital neoplasms, have a strikingly high malignancy rate of 82.4%. ⁷ Critical neurovascular structures in this region include the anterior and posterior ethmoidal arteries (branches of the ophthalmic artery), the nasociliary nerve (providing sensory innervation to the medial canthus and nasal dorsum), and the optic nerve. ⁸ In our patient, epiphora resulted from nasolacrimal duct obstruction, and headache likely reflected sinus involvement. During surgery, we carefully preserved uninvolved neurovascular structures, completely excised the obstructed nasolacrimal duct, and drilled bony margins until healthy tissue was confirmed to minimize residual disease.

3. Lynch Incision Plus Endonasal Endoscopy: A Strategic Combination for Complete Tumor Clearance and Orbital Reconstruction

Surgery remains the cornerstone of treatment for localized SFTs, and achieving negative (R0) margins is the most critical determinant of favorable long-term outcome. ⁹ In the present case, the tumor’s involvement of both the orbit and the sinonasal tract posed a formidable surgical challenge: no single conventional approach could adequately expose both compartments simultaneously. ¹⁰ Traditional transcutaneous medial orbitotomy (Lynch incision) provides excellent access to the medial orbital wall, the orbital apex, and the anterior ethmoid region, but it offers limited visualization of the posterior ethmoid sinuses, maxillary sinus, and nasal cavity. ¹¹ Conversely, the endoscopic endonasal approach is well-suited for tumors located predominantly in the medial and inferior orbit as well as the paranasal sinuses, but it struggles to access the anterior orbit, the supraorbital region, and the orbital apex when the optic nerve is shifted medially. ¹² This complementary limitation of the two approaches informed our decision to adopt a combined strategy: endoscopic endonasal access was used to address tumor extension into the ethmoid and maxillary sinuses and to relieve compression of the nasofrontal duct, while the Lynch incision provided a wide, direct field for resecting the orbital component, reconstructing the orbital walls, and achieving complete tumor clearance under direct visualization. ¹³ This combined approach allowed for en bloc tumor resection with negative margins (R0), as confirmed by histopathological examination. Importantly, it also facilitated simultaneous orbital reconstruction using bone drilling to achieve healthy margins. The postoperative recovery was uneventful, with no wound complications or functional deficits. This case demonstrates that for tumors straddling the orbitonasal junction with extensive bone destruction, a carefully planned combined approach—transfacial medial orbitotomy via Lynch incision plus endoscopic endonasal surgery—offers distinct advantages over any single approach: it provides comprehensive exposure, enables R0 resection, allows for one-stage reconstruction, and minimizes morbidity by avoiding more extensive craniofacial resections.

4. Limitations and Outlook

Several limitations should be acknowledged.First, the Lynch incision, while providing excellent exposure, carries the risk of medial canthal web formation and visible scarring. Second, this combined approach demands surgical expertise in both orbital and endoscopic sinonasal techniques, along with careful consideration of patient-specific factors such as overall health status, tumor extent, and prior surgical history. Third, given that atypical SFT carries a significant risk of recurrence and poor prognosis, long-term follow-up of this patient is essential. We will continue to monitor her closely with serial clinical and imaging examinations.