A patient in his 20s presented with a change in the appearance of his left eye with evidence of relative afferent pupillary defect. Imaging revealed a giant frontoethmoidal osteoma, a benign sinonasal tumour, invading three-quarters of the orbit. Multidisciplinary discussion involving opthalmology, maxillofacial surgery, neurosurgery and otolaryngology resulted in the decision to attempt entirely endoscopic excision of this lesion, which was performed with successful outcomes. This case demonstrates how a sinonasal osteoma should be considered in the differential diagnosis for a patient presenting with proptosis or other eye signs suggestive of compression of the orbital compartment. This case report and literature review highlights the possibility of managing giant sinonasal osteomas with orbital extension through a completely endoscopic approach.

BACKGROUND: The ethmoid sinus (ES) is a three-dimensional (3D) complex structure, a clear understanding of the ES anatomy is helpful to plan intranasal surgery. However, most prior studies use 2D measurements, which may not accurately depict the 3D structure. The current study measured the gender differences in ES morphology based on 3D reconstruction of computed tomography (CT) images.
METHODS: The 3D models were reconstructed using CT images. Twenty-one males and 15 females were enrolled in the study. The ES dimensions, including width, height and aspect ratio (AR) of each cutting-plane section, were measured at 10% increments along with the anteroposterior axis of the ES. The gender differences in the above parameters were further evaluated by an independent t-test.
RESULTS: The width of the ES for males is 12.0 ± 2.1 mm, which was significantly greater than that in females (10.0 ± 2.1 mm). The average height for males is 18.4 ± 3.5 mm, and 18.2 ± 3.4 mm for females. The AR of female (male) is around 0.56 (0.63) for the anterior ES and 0.66 (0.75) for the posterior. There are significant differences between genders in the parameters of width and AR (p < 0.05).
CONCLUSIONS: This study found that the aspect ratio greatly varies along the length of ES, indicating that the cross-section of the ES in the anterior is closer to an elliptical shape and turns closer to a circular shape near its posterior. There is a significant difference between genders in width and aspect ratio. The results would be helpful to know the complex anatomic details of the ethmoid sinus.

Objective:To investigate the criteria for selecting surgical approaches for frontal and ethmoid sinus osteomas of different locations and sizes on CT imaging. Methods:Using sagittal and coronal CT images, the following lines were delineated: the F-line（a horizontal line passing nasofrontal beak）, the M-line（a vertical line passing paries medialis orbitae）, and the P-line（a vertical line passing the center of the pupil）. Classification of frontal and ethmoid sinus osteomas was based on their relationship with these lines. Appropriate surgical approaches were selected, including pure endoscopic approaches, endoscopic combined with eyebrow incision approach, and endoscopic combined with coronal incision approach. This method was applied to a single center at the Third Affiliated Hospital of Sun Yat-sen University for endoscopic resection of frontal and ethmoid sinus osteoma. Case Data: Sixteen cases of ethmoid sinus osteomas were treated from January 2020 to September 2023. Among these cases, there were 9 males and 7 females, with ages ranging from 18 to 69 years, and a median age of 48 years. Results:Thirteen cases underwent pure endoscopic resection of the osteoma, while in three cases, a combined approach was utilized. Among the combined approach cases, two exceeded both the M-line and the F-line but did not cross the P-line; therefore, they underwent endoscopic combined with eyebrow incision approach. One case exceeded all three lines and thus underwent endoscopic combined with coronal incision. In all cases, complete resection of the osteoma was achieved as per preoperative planning, and none of the patients experienced significant postoperative complications. Conclusion:For frontal and ethmoid sinus osteomas, it is advisable to perform a thorough preoperative radiological assessment. Based on the size of the osteoma and its relationship to the three lines, an appropriate surgical approach should be chosen to optimize the diagnostic and treatment plan.
目的：探讨在CT影像上不同位置和大小额筛窦骨瘤的手术入路选择标准。 方法：分别在鼻窦矢状位和冠状位CT上选择F线（额嘴水平线）、M线（眶内侧壁线）、P线（瞳孔中心垂直线），根据额筛窦骨瘤和F线、P线、M线的关系进行分类，并选择合适的手术入路（包括单纯内镜入路、内镜联合眉弓切口入路及内镜联合冠状切口入路），2020年1月-2023年9月中山大学附属第三医院收治的16例额筛窦骨瘤患者均应用此方法完成额筛窦骨瘤切除手术，其中男9例，女7例；年龄18～69岁，中位年龄48岁。 结果：16例患者中，13例单纯内镜下切除骨瘤；3例采用联合入路，其中2例超越M线及F线且未过P线者采用内镜联合眉弓切口入路，余1例超越三线者采用内镜联合冠状切口入路。患者的骨瘤均按照术前设计得到完整切除，术后均未发生明显并发症。 结论：额筛窦骨瘤术前建议影像学上仔细评估，根据骨瘤的大小及三线的位置关系，选择合适手术入路，优化诊疗方案。.

BACKGROUND: The first report of cerebrospinal fluid rhinorrhea (CSFR) was described in 1679. In 1826 it was reported that one of the possible causes of CSFR was a fistula between the subarachnoid space and the nasal cavity. In 1903, chemical analysis of the fluid was proposed as a diagnostic criterion. In Mexico there has been 32 case reports.
METHODS: Forty-nine years old female with a history of nasal polyposis, profuse rhinorrhea and cephalea who attends the allergy department with the suspicion of allergic rhinitis. After anamnesis and physical evaluation, CSFR was suspected. Chemical analysis of the fluid, head CT and biopsy of nasal polyp were performed. An etmoidal fistula associated with carcinoma was confirmed.
CONCLUSIONS: Spontaneous fistulas are rare but can erosionate the bone and adjacent tissues. Diagnosis is based on the clinical findings, patient\'s history and complementary studies such as beta-2-transferrin determination in nasal fluid.
BACKGROUND: En 1679 se describió el primer caso de rinorrea de líquido cefalorraquídeo. En 1826 se reportó como causa una fistula entre el espacio subaracnoideo y la cavidad nasal. Para 1903 se propuso el análisis químico como criterio diagnóstico. En México sólo se han reportado 32 casos de rinorrea de líquido cefalorraquídeo.
UNASSIGNED: Paciente femenina de 49 años, con antecedente de poliposis nasal, rinorrea abundante y cefalea, quien acudió a consulta para descartar rinitis alérgica. Luego de la anamnesis y la exploración física se sospechó de fuga de líquido cefalorraquídeo secundaria a fístula nasal. Con la histoquímica de moco, tomografía de cráneo y biopsia del pólipo nasal se estableció el diagnóstico de fístula etmoidal secundaria a carcinoma.
UNASSIGNED: La fístulas espontáneas son excepcionales, pueden erosionar el hueso y los tejidos adyacentes. El diagnóstico se establece con la historia clínica y los antecedentes médicos, además de estudios complementarios y la determinación de Beta-2-transferrina en moco.

BACKGROUND: The present investigation documented a case of bilateral sinonasal inverted papilloma (SNIP) that arose from both sides of the frontal sinus and ethmoid sinus. The occurrence of bilateral involvement of the nasal cavities and frontal sinus is rather infrequent.
METHODS: Informed consent was obtained from the patient.
METHODS: Bilateral SNIP.
METHODS: The tumor was completely removed by Draf III endoscopic resection complemented by an external eyebrow arch approach, and the postoperative recovery was uneventful.
RESULTS: The purpose of this paper is to present a comprehensive reference for the management of bilateral SNIP that affects the frontal sinuses.
CONCLUSIONS: This study addresses the staging and surgical management of bilateral SNIP, along with a review of the factors contributing to its recurrence. The recommended treatment method involves applying the Draf III technique combined with an external nasal approach.

A 14-year-old girl suffered a rare injury when a pen pierced her left eye, leading to a foreign object lodged in her ethmoid sinus. Prompt diagnosis and endoscopic sinus surgery (ESS) effectively removed the object, highlighting ESS as a valuable approach for managing uncommon sinus foreign bodies while minimizing complications.

Teratomas are rare neoplasms that arise from totipotent stem cells. Teratomas of the head and neck are extremely rare, constituting about 10% of all cases and usually present in the neonatal period. Extensive literature search has shown that there are only two cases reportedof teratoma of the ethmoid sinus; one as a mature teratoma in a neonate and another was histologically immature teratoma in an adult male (Mwang\'ombe et al. in East Afr Med J 79(2):106-107, 2002; Aggarwal et al. in J Postgrad Med 59(2):138-141, 2013). We hereby report the second case of immature teratoma of ethmoid sinus origin in an adult male.

OBJECTIVE: To analyze variability in the distance between the Anterior Ethmoidal Artery (AEA) and the anterior Skull Base (SB), as well as the frequency of lateral asymmetry in a Latin American population using computed tomography.
METHODS: A total of 250 computed tomography scans of paranasal sinuses in coronal reconstruction (500 AEAs) were analyzed. After determining the image with the best anatomical view of the artery, the distance between its midpoint and the ethmoidal roof was measured, and the images were independently interpreted by 2 physicians.
RESULTS: Of the 500 AEAs, 279 (55.8%) adhered to or passed through the SB at a distance of 0mm. A total of 221 AEAs (44.2%) were at some distance from the SB, of which 107 (48.4%) were on the right side, ranging from 1.18 to 6.75mm, and 114 (51.5%) were on the left side, ranging from 1.15 to 6.04mm. The overall mean distance between the AEA and SB was 1.22 (SD=1.57) mm, increasing to 2.77 (SD=1.14) when the arteries adhered to the SB were excluded. Seventy-six individuals (30.4%) had a lateral distance variation > 1mm.
CONCLUSIONS: Our study includes the largest sample of AEA analyzed with computed tomography scans of paranasal sinuses. There was some distance between the AEA and SB in almost half the patients, and we found a high rate of lateral variability >1mm.
METHODS: Level 3.

BACKGROUND: The lamina papyracea is the thin line between the ethmoid sinus and the medial orbital wall. Knowledge of the presence of the lamina papyracea dehiscence (LPD) bears critical importance to prevent misdiagnosis of fractures at this level and to define the anatomy before sinonasal surgery, including Functional Endoscopic Sinus Surgery (FESS). The present study is therefore intended to determine the incidence of LPD in paranasal computed tomography, to identify its imaging characteristics in CT, and to compare with the literature.
METHODS: The current study included patients who underwent paranasal CT scanning for any reason in our clinic between January 2018 and January 2022. Patients were evaluated in terms of age, gender, and presence of LPD. Patients with dehiscence were evaluated in terms of age, gender, dehiscence localization (right, left), tissue at the level of dehiscence, dehiscence size, and dehiscence grade.
RESULTS: 1000 patients with a mean age of 32. ± 16.3 (min = 18-max = 79) were included in the study. 20 patients (2%) were found to have LPD. Of those with LPD, 14 (70%) were grade 1, 4 (20%) were grade 2 and 2 (10%) were grade 3. Again of those with LPD, 14 (70%) had LPD localized on the right and 6 (30%) had LPD on the left. In 12 (60%) of the patients with LPD, herniated tissue was detected. Among these patients with herniation, fatty tissue herniation was observed in 10 (83.3%) and medial rectus muscle herniation was observed in 2 (16.7%).
CONCLUSIONS: Comprehensive evaluation for and identification of LPD are very important before possible sinus surgery.

Osteomas are slow growing fibro-osseous lesions. Very rare to occur in paranasal sinuses. Small osteomas don\'t require any intervention. Giant osteomas may require surgical intervention due to its cosmetic and functional compromises. A 28 year old male presented with swelling over forehead and left orbit for more than 4 years. The swelling is around 6 × 5 cm with gross lateral and inferior deviation of left eyeball. Extradural fronto-ethmoidectomy was done with combined external and endoscopic approach. There was pearly white bony hard, fixed tumor mass seen infiltrating anterior and posterior table of frontal bone. All the tumors removed in piecemeals. Wait and watch policy is the usual treatment policy for small and asymptomatic osteomas. Combine external and endoscopic approach is the treatment of choice for giant frontoethmoid osteoma.