Clinical outcomes
The study included 16 patients with OSFT, 8 patients were males and 8 patients were females. They were treated by two kinds of surgical operation, 29 operations in total. The average age of treatment was 37 ± 7 years, the median follow-up time was 74 (8, 154) months.
Imaging characteristics
One OSFT was located in the extraconal space, fifteen in the retrobulbar intraconal space. Eleven OSFTs involved the cavernous sinus, superior orbital fissure area, and involved the endocranium. On T1-weighted images, all OSFTs seemed to be equally intensities to gray matter. On the T2-weighted image, the lesion showed anisotropic intensity in 15 patients and low intensity in 1 patient. Contrast-enhanced MRI showed that all lesions showed significantly enhanced heterogeneity. Fifteen OSFTs were accompanied by the proliferation, absorption, and destruction of orbital wall bone from CT scans.
Histopathology and immunohistochemistry characteristics
All 16 patients received in our center underwent 29 operations, and all samples were diagnosed as OSFT by pathology. Surgical samples were collected for histological and immunohistochemical analyses. Immunohistochemical studies for CD34, CD99, Bcl-2, SMA, S-100 protein, Ki-67, CK, CD117 were tested in all samples. The CD34 was positive in all pathological samples (16/16, 100%). The Ki-67 index of all 29 surgical samples was 5% - 20%. Besides, OSFTs has been showed to exhibit strong positivity with vimentin (12/16, 76%), CD99 (9/16, 56.3%), and Bcl-2 (11/16, 68.8%). EMA (2/16, 12.5%) and SMA (6/16, 37.5%) are occasionally detected, while OSFT is usually rare for S-100 (1/16, 6.3%) and CK (1/16, 6.3%) expression.
The follow-up results
Sixteen patients completed follow up, the median follow-up time was 74 (8, 228) months. All patients with OSFT underwent a total of 29 operations, of which 12 were transorbital approach operations and 17 were transfronto-orbital approach operations. Ten patients (10/16, 62.5%) had recurrence. The recurrence rate of transorbital approach operations was 83.3% (10/12), and the recurrence rate of transfronto-orbital approach operations was 17.6% (3/17). The overall recurrence rate of surgery was 44.8% (13/29). No patients had treatment-related complications (Table 1).
Table 1: Surgical approaches and postoperative follow-ups of 16 cases of OSFTs.
Patient No./Sex
|
Symptoms
|
Side
|
Treatment and Surgical Approach
|
Tumor location and involvement
|
Immuno-histochemistry
|
Progress
|
Prognosis
|
Follow-up time, m
|
CD34
|
Ki-67
|
1/F
|
Proptosis; Vision loss
|
R
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
|
+
|
+(<10%)
|
Improvement of the proptosis and vision
|
Recurrence
|
120
|
Proptosis; Vision loss
|
R
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Improvement of the proptosis and vision
|
None recurrence
|
92
|
2/F
|
Proptosis; Vision loss
|
L
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
|
+
|
+(< 10%)
|
Improvement of the proptosis and vision
|
Recurrence
|
34
|
Proptosis; Vision loss
|
L
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
|
+
|
+(< 10%)
|
Improvement of the proptosis and vision
|
Recurrence
|
28
|
Proptosis; Vision loss
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Improvement of the proptosis and vision
|
None recurrence
|
24
|
3/M
|
Proptosis; Visual field defect; Ocular movement disorder
|
L
|
Transorbital approach
|
Inside the muscle cone
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
Recurrence
|
18
|
Proptosis; Visual field defect; Ocular movement disorder
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
24
|
4/M
|
Proptosis; Vision loss
|
R
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
Recurrence
|
24
|
Proptosis; Blindness
|
R
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit
|
+
|
+(< 10%)
|
Orbital exenteration
|
Recurrence
|
8
|
Cranio-orbital mass
|
R
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure;
Subdural brain tissue
|
+
|
+(< 20%)
|
The mass disappeared
|
None recurrence
|
35
|
5/F
|
Proptosis
|
R
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 5%)
|
Improvement of the proptosis
|
None recurrence
|
82
|
6/M
|
Proptosis
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit
|
+
|
+(< 5%)
|
Improvement of the proptosis
|
Recurrence
|
228
|
Proptosis;
Blindness
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 5%)
|
Improvement of the proptosis
|
None recurrence
|
31
|
7/F
|
Proptosis
|
R
|
Transorbital approach
|
Outside the muscle cone
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
30
|
8/F
|
Proptosis; Vision loss;
Ocular movement disorder
|
R
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
Recurrence
|
72
|
Proptosis; Vision loss;
Ocular movement disorder
|
R
|
Transorbital approach
|
Inside the muscle cone;
lateral wall of the orbit
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
Recurrence
|
72
|
Proptosis; Vision loss;
Ocular movement disorder
|
R
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
53
|
9/M
|
Proptosis; Vision loss;
Ocular movement disorder
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
Recurrence
|
54
|
Proptosis; Vision loss;
Ocular movement disorder
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Blindness
|
Recurrence
|
45
|
10/F
|
Proptosis; Vision loss;
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Blindness
|
Recurrence
|
154
|
Proptosis; Blindness
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
43
|
11/M
|
Proptosis; Vision loss
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone
|
+
|
+(< 5%)
|
Improvement of the proptosis
|
None recurrence
|
57
|
12/F
|
Proptosis; Vision loss
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone
|
+
|
+(< 5%)
|
Improvement of the proptosis
|
None recurrence
|
74
|
13/F
|
Proptosis; Vision loss
|
R
|
Transorbital approach
|
Inside the muscle cone
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
Recurrence
|
36
|
Proptosis; Vision loss;
pain
|
R
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus and superior orbital fissure
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
125
|
14/M
|
Proptosis; Vision loss
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
11
|
15/F
|
Proptosis; Vision loss
|
L
|
Transorbital approach
|
Inside the muscle cone;
|
+
|
+(< 10%)
|
Improvement of the proptosis and vision
|
Recurrence
|
78
|
Proptosis; Vision loss
|
L
|
Transfronto-orbital approach
|
Inside the muscle cone;
lateral wall of the orbit;
cavernous sinus
|
+
|
+(< 10%)
|
Improvement of the proptosis
|
None recurrence
|
30
|
16/M
|
Proptosis
|
L
|
Transorbital approach
|
Outside the muscle cone lateral wall of the orbit
|
+
|
+(< 5%)
|
Improvement of the proptosis
|
None recurrence
|
28
|
Typical cases analysis
OSFT is an extremely rare intraorbital tumor. This tumor mostly originates from mesenchymal cells in the orbit and often involves the bone in the orbit. Even more, it breaks through the bony fissure of the cranial orbit and invades the intracranial structure. Most of these tumors require surgical treatment, and radiotherapy and chemotherapy are not sensitive. Clinically, the postoperative recurrence of tumors is very common. Most of these tumors are first diagnosed in ophthalmology, and most of the first operations are performed by ophthalmologists. However, some OSFTs are not suitable for ophthalmic surgery based on their location and scope of involvement. For example, the tumor is located in the retrobulbar muscle cone (Figure 1). It is difficult to ensure the protection of the optic nerve through the ophthalmic surgical approach. Neurosurgery can better expose the tumor, give the incision of the periosteum of orbit, explore the medial side of the superior rectus muscle, and then completely remove the tumor. Sometimes OSFT grows into the skull along the supraorbital fissure and involves the dura mater. The lateral orbital approach is difficult to completely remove the tumor and at the same time, expand the bone and dura mater involved by the tumor. The remaining tumor will cause the tumor to recur. The craniotomy can fully expose the supraorbital tumor. After the transfronto-orbital approach was given to the craniotomy, the MRI re-examinations immediately after the operation showed that the tumor and involved dura were removed completely (Figure 2). When the tumor further involves the intracranial structure, it will invade the cavernous sinus and even the intracranial brain tissue (Figure 3). In this situation, craniotomy can still completely remove the tumor. Generally, it is difficult for the tumor to break through the bilateral dural structure of the cavernous sinus. Adequate exposure, remove the tumor in pieces, and protect the internal carotid artery, oculomotor nerve, trochlear nerve, abductor nerve, and trigeminal nerve (V1, V2). The enlarged surgical field can not only prevent the traction of the orbital contents but also ensure that all the tumor-involved areas are removed. In our clinical cases, we found that most of the OSFT involved periorbital bone to varying degrees, and all craniotomy operations involved extensive removal of the involved bone (Figure 4-6). The tumors located on the lateral or superior side of the orbit are often accompanied by bone destruction, absorption, and hyperplasia. Wrong surgical procedures and missed imaging studies often accompany tumor recurrence. The forcible removal of the skull base through the transorbital approach may result in cerebrospinal fluid leakage contusion and laceration of the brain. It is difficult to adequately deal with the involved periorbital or skull base bone with the ophthalmic surgical approach, which left a hidden danger to the recurrence of the tumor. In the case of tumors involving the periorbital and skull base bones, we have adopted craniotomy. The tumor is completely resected through the transfronto-orbital approach. It is worth noting that during the operation, the affected bone must be extensively removed, and the involved dura mater and brain tissue must be removed completely. In this study, most of the patients we treated were patients who relapsed after ophthalmic surgery or patients who were difficult to remove completely with ophthalmic surgery alone. For this type of patient, we believe that the can give a total resection of the tumor and reduce the recurrence of the tumor.