Research outcome measures:

1. Primary (main):

   To Evaluate the Gross Total Resection Rate Using Endoscopic Approach for Lesions Extended To Anatomically Challenging Areas

2. Secondary (subsidiary):

   1. Assess postoperative improvement in Quality of Life
   2. Quantify intraoperative blood loss and surgical duration
   3. Document the incidence of complications (CSF leak, nerve palsy, vascular injury)

Sinonasal tumors are a heterogeneous group of neoplasms arising from the nasal cavity and paranasal sinuses, representing a rare subset of head and neck tumors. Tumors arising from the sinonasal cavity can be subdivided into benign and malignant characters .Sinonasal malignancy are rare, representing <1% of all malignancies and <5% of head and neck cancers.Benign sinonasal tumors are more common than malignant lesions and include inverted papilloma, hemangioma, osteoma, juvenile nasopharyngeal angiofibroma, and various fibrous and glandular neoplasms.(1)The sinonasal cavity includes the epithelial, mesenchymal, salivary gland, cartilaginous and osseous proponents, and as such, it may lead to various original malignancies including the squamous cell carcinoma (most common) and the others (adenocarcinoma, adenoid cystic carcinoma, sarcoma, olfactory neuroblastoma,).(2) Surgical resection is often the first step of the therapeutic strategy in treatment of sinonasal tumors, possibly combined with adjuvant therapies .Tumors at pterygopalatine and infratemporal fossae,sphenoid and maxillary sinus poses challenges to surgeons for their deep location and intimate relationship with highly functional neurovascular and osteo-muscular structures .(3)Tumors in these challenging regions were managed via invasive open surgical resection ,these interventions are frequently morbid, resulting in profound neurological and functional sequelae that adversely impact the patient's clinical outcomes.(4) Endoscopic endonasal surgery become a standard approach in the management of many benign and selected malignant sinonasal tumors .It is as a minimally invasive surgical alternative, facilitating access to difficult locations with preserving the osteo-ligamental and muscular structures with no visible scars, optimal cosmetic outcome, and consequently limited risk of permanent neurological or functional deficits.(5)

Inclusion Criteria:

-Patients with sinonasal and nasopharyngeal tumors

Exclusion Criteria:

• Extensive lesions required open approach ex (intraconal extension need orbital exenteration).
• Absolute contraindications to general anaesthesia.