EES is considered as an extremely malignant tumor which usually composes of undifferentiated small round cells of unknown origin and shows neuroectodermal differentiation of variable degrees [7].
The occurrence of Ewing’s sarcoma in the oral and maxillofacial area is not usual which represents only 4% of soft tissue tumors and about 1.5-4% of childhood sarcomas [8]. However, very few cases originating from the sublingual region have been reported to date.
In a clinical aspect, approximately 75% of patients with EES present with a rapidly growing enlargement that is usually with less pain than its bony counterpart, and 30% of patients exhibit distant metastases at the time of diagnosis [9]. These tumors tend to spread locally, invade surrounding facial surfaces, and moreover invade muscles and bone. The rarity of EES makes it challenging to determine the optimal diagnosis and management of these tumors. However, recent progress in chemotherapy and radiotherapy, and the use of aggressive surgical procedures have improved the overall survival rate of these cases [5].
Herein, a 37-year-old patient suffered from a recurring painful swelling with difficulty in swallowing in the left sublingual region. Consistent with this case, the typical peak incidence of this tumor is between 5 and 25 years of age and occurs more frequently in males than in females. Some studies have reported a male prevalence of between 1.4.
1 and 2.4:1 in the head and neck areas which matches this case. However, a recent report establishes a relatively balanced gender distribution, with only a minor female predominance of 1.05: 1 [10,11]. After the biopsy was taken from the patient, histopathology revealed a strong blue color that demarcates Ewing’s sarcoma which goes to the blue round cell tumors group. Thus, immunohistochemistry was an elemental assessment to exclude the differential diagnosis. In the current case, the CD-99 marker was used which is known as a cell membrane glycoprotein that usually appears in all ES and PNET with a positive immunoreaction in 98% of the cases [11].
The CD-99 marker has also been identified in many other blue round cell tumors such as rhabdomyosarcoma, small cell carcinoma, lymphomas, and sarcoma such as poorly differentiated synovial sarcoma [6]. In this current report, the probability of another blue round cell tumor such as rhabdomyosarcoma, small, and lymphomas (plasmablastic lymphoma) can be ruled out due to the negativity reaction to leukocyte common antigen (LCA), myogenin, pancytokeratin and CD -38 markers (Table.1).
Interestingly, the presence of this tumor in the sublingual region is a rare finding, so very little information in the literature was reported about the presentation of the extraosseous type in this location. Therefore, a definite clinical description of this entity in the sublingual region was not covered. The signs and the characteristic symptoms of this sarcoma are varied which usually depends on the site of origin. Throughout the years, numerous therapeutic modalities have been established, depending on the site and extension of the tumor. Many treatment modalities were reported for EES such as surgery, chemotherapy, and radiotherapy [12].
EES presents with a poor prognosis which usually increases in presence of some risk factors such as old age, pelvic involvement, high WBC, elevated LDH, and low Hb at the time of diagnosis. In addition, initial tumor size was also reported as a risk factor and was considered as a strong prognostic factor in the disease. Yet, it was reported that using neoadjuvant chemotherapy as a treatment modality revealed a great histopathological response for ESS previously diagnosed cases [13].
Management of the patient in the current case report was done using both chemo/radiotherapies. Unfortunately, despite appropriate treatment, the lesion proceeded from a localized form to a metastatic form. In our opinion, the major causative factor would be the late diagnosis of this tumor which resulted in a delay in the handling of the case which finally led to the lack of response to the management and ended up with the development of multiorgan metastasis.