We present the case of a 46-year-old female with a history of hysterectomy for a high-grade squamous intraepithelial lesion in the cervix, several allergies, and seasonal rhinitis treated with montelukast. She presented with sudden posterior epistaxis that was partially treated with nasal packing. She underwent a first endonasal biopsy that reported an unresectable tumor in the right nasal cavity, with negative markers for esthesioneuroblastoma; a microscopic focus of poorly differentiated carcinoma with positive CKAE1/AE3 and negative CD56 and PS100 was reported []. Treatment was started with three cycles of cisplatin-based chemotherapy and radical RT in two phases. The first RT phase consisted of 45 Gy in 25 fractions to the neck and primary lesions. Subsequently, a second biopsy was obtained, which contained residual microscopic foci of poorly differentiated carcinoma, with lymphatic and vascular permeation associated with extensive necrosis and fibrosis due to RT. The second phase of RT consisted of 23 Gy in 12 fractions, resulting in tumor shrinkage. Finally, maintenance therapy with biweekly cetuximab was started. Afterward, magnetic resonance imaging (MRI) was performed [], revealing an extra-axial mass that caused skull base erosion, and displacement of the right frontal orbital region, without invasion of brain parenchyma or meninges. The lesion occupied the right nostril, invading the right maxillary, ethmoidal, sphenoidal, and frontal sinuses and extending into the ipsilateral orbital cone. A subsequent positron emission tomography (PET)/ computed tomography CT scan reported hypermetabolism in the right nasal structures without systemic dissemination or cervical lymph node metastasis. Clinically, she reported a right hemicranial headache with a visual analog scale of 8/10, paresthesias in the ipsilateral hemiface, weight loss, vertigo, persistent nasal congestion, anosmia, and neuropathic pain in the extremities. At anterior rhinoscopy, a grayish polypoid mass was found in Cottle Zone III, occupying the entire right nostril. The neurological evaluation showed mild dysarthria, impaired judgment, no abstraction capacity, anosmia, an afferent pupillary defect in the right eye, and hypomimia. She was transferred to the operating room and placed in a supine position. The head was fixed on a Mayfield headset and rotated 15° to the left; a bicoronal Soutar incision was performed. The surgical strategy was an endoscopictranscribiform resection with pericranial plasty in two surgical stages. At first, the neuro-otology team performed an endoscopic examination with a 0° rigid lens to resect the calcified portion of the tumor with a chisel and continue with its demassification. In the second stage, the neurosurgical team continued with resection from the lateral wall and floor of the nasal cavity. A Draff III procedure was performed for anterior skull base dissection, communicating the frontal sinuses with the nasal cavity []. A soft intracranial lesion was completely resected, which presented mild infiltration of the right rectus gyrus. To repair the defect, the dural substitute was placed in an inlay fashion followed by autologous fascia lata; pericranium was extracted from a previous bicoronal incision, and it was used to finally cover the defect []. The patient presented an uneventful postoperative course with symptomatic improvement; an MRI was conducted [], finding no residual lesion or compromise of adjacent structures. Given the extension of the tumor, she was evaluated by the neuroendocrinology staff, which found no evidence of biochemical alteration of pituitary hormones. One week later, she presented a transnasal cerebrospinal fluid fistula, which was successfully treated with antibiotics, lumbar drainage, and acetazolamide, with no clinical evidence of infection, after which, she was discharged. To date, the patient maintains an adequate quality of life 1 year after the onset of symptoms.