OF THE UPPER RESPIRATORY TRACT: A CASE REPORT AND REVIEW OF LITERATURE

Introduction. Leiomyosarcoma is a malignant smooth muscle tumor that is most often found in the gastrointestinal tract, uterus and retroperitoneum. It is uncommon in the upper respiratory tract. Case report. A 53-year-old woman sought treatment for a 3-month history of nasal obstruction and facial pain. An endoscopic examination revealed a polypoid mass involving the right nasal cavity. The patient was operated. During surgery, a bulky tumor mass was found which involved posterior part of the right inferior concha projecting into the lumen of the epipharynx and upper part of oropharynx . The lesion was completely excised with adequate margins of uninvolved tissue. Histologic slides stained with hematoxylin and eosin showed interlacing fascicles of atypical spindle-shaped cells. Mitotic figures and bizarre giant cells were frequently observed. Immunohistochemical staining revealed that the tumor was positive for smooth muscle actin and h-caldesmon and negative for S-100. Histological and immunohistochemical features were consistent with leiomyosarcoma. The follow-up was regularly performed by nasal endoscopy and CT, and disease-free period is 53 months so far. Conclusion. To the best of our knowledge, this is the longest disease-free period in a patient with leiomyosarcoma of the upper respiratory tract since 1996. This tumor has obscure clinical behavior and prognosis, so we believe it is necessary to have more published data to determine the best combination of existing therapies, as well as potential new therapies, and enable a longer survival period.


Introduction
Leiomyosarcoma is a malignant smooth muscle tumor that is most often found in the gastrointestinal tract, uterus, and retroperitoneum 1 . It is uncommon in the upper respiratory tract. Only 1.5-2.3% of soft tissue tumors in the nasal cavity, paranasal sinuses, and nasopharynx are diagnosed as leiomyosarcomas 1,2 . Compared to uterine and gastrointestinal variants, tumors involving this localization are much more aggressive and have a worse outcome 3 .

Case report
A 53-year-old woman sought treatment for a 3-month history of nasal obstruction and facial pain. Rhinoscopy was performed and reddish polypoid mass involving the right nasal cavity was discovered. The patient was referred to computed tomography scan, which Histological and immunohistochemical features were consistent with leiomyosarcoma.
According to the French Federation of Cancer Centers Sarcoma Group 4 , the histologic grade was 2. The lymphovascular invasion was not identified.
The patient did not receive any adjuvant therapy. The follow-up was regularly performed by nasal endoscopy and CT, and disease-free period is 53 months so far.

Discussion
As mentioned earlier, leiomyosarcoma of the upper respiratory tract is very rare. The first case of leiomyosarcoma of the nasal cavity was documented by Dobben in 1958. He Prognosis is variable, and it depends on location, tumor size, the status of surgical margins, and histologic grade 2,14 . Kuruvilla et al. reported that prognosis is poorer for cases extending to ethmoid sinus, rather than those localized in the nasal cavity 2 . Also, tumor diameter greater than 5 cm is considered a poor prognostic factor 19 . However, small lesions of the paranasal sinuses could behave more aggressively and have a higher risk of local recurrence than larger tumors in the nasal cavity because of their closer anatomic proximity to vital structures 2 . The treatment of choice is radical resection with tumor-free surgical margins. In many cases, complete resection with negative margins is very hard to achieve, and in these cases, the mortality rate is much higher 3 . In our case, the tumor-free surgical margin was successfully obtained. Histologic grade is an important prognostic factor, and strongly correlates with prognosis 20 . It is recommended that histologic grade is determined by the French Federation of Cancer Centers Sarcoma Group, which is the most used soft tissue grading system. It has three grades, and it is based on three parameters: differentiation, mitotic activity, and necrosis 4 .
Pathohistological evaluation is necessary for a definitive diagnosis of leiomyosarcoma.
Histologically, leiomyosarcoma is a spindle cell tumor with moderate to marked nuclear atypia, frequent necrosis, and brisk mitotic activity. Immunohistochemistry is essential to differentiate leiomyosarcoma from other neoplasm with spindle cell morphology such as sarcomatoid carcinoma, spindle cell melanoma, malignant peripheral nerve sheath tumor and rabdomyosarcoma. Positive smooth muscle markers and negative S100, and cytokeratin AE1/AE3 are crucial for diagnosis 3,21 .
Leiomyosarcoma has a high rate of local recurrence of 50-75% within the first year 21,23 .
According to the survey, the 5-year survival rate for leiomyosarcoma of the nasal and paranasal sinuses is 20% 8,23,24 . It tends to spread hematogenously, mainly to the lungs, liver, and bones 8 . Regional lymph nodes involvement is rare, but there are few reports of sinonasal leiomyosarcoma with cervical lymph node metastasis 25,26

Conclusion
Our patient didn't have any of the risk factors. The tumor had good prognostic factors like localization in the nasal cavity, total tumor size less than 5 cm and tumor-free surgical margins. To the best of our knowledge, this is the longest disease-free period in a patient with leiomyosarcoma of the upper respiratory tract since 1996. This tumor has obscure clinical behavior and prognosis, so we believe it is necessary to have more published data to determine the best combination of existing therapies, as well as potential new therapies, and enable a longer survival period.