Nasal inverted papilloma (NIP) is one of the most common benign neoplasms in rhinology. It is characterized by a high degree of epithelial hyperplasia, with epithelial masses that penetrate tubularly or finger-like into the subcutaneous mesenchyme, resulting in a characteristic appearance. The appearance is generally papillary or myxoid as shown in Figure 1, and sometimes the tumor has polyp-like changes, so it is often misdiagnosed as nasal polyp. Symptoms: It may manifest as nasal congestion, pus, or blood in the nose. The onset is mostly unilateral. Onset characteristics: Individuals with the first onset of the disease often have a local origin of the tumor, and this is the center of origin, which can be located in the nasal cavity or in the sinuses, and the order of the most frequent sinuses is generally: septal sinus 〉 maxillary sinus 〉 pterygoid sinus 〉 frontal sinus. The tumor’s trophoblastic vessels are often present in this germinal center, which often causes more obvious bleeding when the tumor is removed to the root tip during surgery. At the same time, due to the influence of tumor tissue invasion on the adjacent bone, the adjacent bone at the origin of this tumor often shows gross, blurred or thickened phenomena (Figure 2). This provided us with a basis for preoperative diagnosis of the disease by imaging data (mainly sinus CT). In the case of recurrent cases, this imaging feature is atypical because of the multicentric origin or even extensive involvement. In addition, the disease may show a distinct “cerebral gyrus sign” on enhanced MRI. Treatment: Once the tumor is diagnosed, it should be treated surgically as soon as possible. The most ideal procedure is nasal endoscopic resection of the tumor. Of course, if local hospitals are not equipped with nasal endoscopic surgery, open surgery with lateral nasal incision is also possible as long as complete resection is possible. The first chance of surgery should be especially cherished because it is probably the highest chance of complete removal of the tumor. If the origin of the tumor can be clearly identified during the surgery, and the tumor can be adequately excised locally (sometimes by grinding away the diseased bone), then it will be possible to “finish the job in one go”. Generally speaking, the more recurrent the case is, the more difficult the surgery is. This is because the site of tumor is no longer typical and may be diffuse, and the scarring from the previous surgery may affect the identification and removal of the tumor during surgery. Prognosis: The disease has a certain tendency of malignant transformation, therefore, doctors should cherish every surgical opportunity. Therefore, doctors should cherish every opportunity to operate and try to “end” the tumor in their own hands before it becomes malignant. Other: Endoscopic surgical techniques are the best choice for the treatment of involuted papilloma because of the minimal trauma and quick recovery. At the current technical level, the most difficult tumors are those of the primary frontal sinus, which require skillful large-angle (70°) endoscopic techniques and the necessary adjuvant incisions (e.g., brow arch incision) to complete the procedure. The most risky is the tumor of the primary pterygoid sinus, especially in cases with bony destruction of the lateral wall of the pterygoid sinus. This is because of the possibility of fatal hemorrhage caused by intraoperative injury to the internal carotid artery. The tumors of septal sinus and maxillary sinus origin are the arena where the nasal endoscopic surgical technique can shine. Figure 1AFigure 1BFigure 1A: Endorectal papilloma of right frontal sinus origin seen intraoperatively; 1B: Nasal endoscopy seen 2 months after nasal endoscopy. The mucosa is smooth and the operative cavity is epithelialized. Figure 2 Endorectal papilloma of left nasal cavity with growth site in the left septal sinus and tumor root base causing marked osteophytes (as drawn in the circles).