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.

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.

OBJECTIVE: Inherent complex angioarchitecture associated with ethmoidal dural arteriovenous fistulas (dAVFs) can make endovascular treatment methods challenging. Many surgical approaches are accompanied by unfavorable cosmetic results such as facial scarring. Blepharoplasty incision of the eyelid offers a minimal, well-hidden scar compared with other incision sites while offering the surgeon optimal visualization of pathogenic structures. This case series aims to report an initial assessment of the safety and efficacy of supraorbital craniotomy by blepharoplasty transpalpebral (eyelid) incision for surgical disconnection of ethmoidal dAVFs.
METHODS: Retrospective chart review was conducted for all patients who underwent blepharoplasty incision and craniotomy for disconnection of ethmoidal dAVFs at our institution between October 2011 and February 2023. Patient charts and follow-up imaging were reviewed to report clinical and angiographic outcomes as well as periprocedural and follow-up complications.
RESULTS: Complete obliteration and disconnection of ethmoidal dAVF was achieved in all 6 (100%) patients as confirmed by intraoperative angiogram with no resulting morbidity or mortality. Periprocedural complications included one case of transient nasal cerebrospinal fluid leak that was self-limiting and resolved before discharge without intervention.
CONCLUSIONS: Surgical treatment for ethmoidal dAVFs, specifically by transpalpebral incision and supraorbital craniotomy, is a safe and effective treatment option and affords the surgeon greater access to the floor of the anterior fossa when necessary. In addition, blepharoplasty incision addressed patient concerns for facial scarring compared with other incision sites by creating a more well-hidden, minimal scar in the natural folds of the eyelid for patients with an eyelid crease.

A 41-year-old woman showed a palpable mass at the superonasal orbital edge on the right side. Magnetic resonance imaging demonstrated a lobulated fluid-containing tubular mass which extended anteriorly to posteriorly along the medial orbital wall, nasal to the eyeball. She was followed once a year for 8 years until the age of 49 years when she decided to undergo surgical resection because of the enlarged mass. The lobulated large mass was resected and the pathology showed sparsely distributed spindle cells, positive for CD34, in alcian blue-positive mucous substances, indicative of myxoma. Postoperative magnetic resonance imaging showed residual lobulated tubular mass along the optic nerve on the medial side and superior to the eyeball. The residual orbital mass showed stable structure with more evident connection with the ethmoid sinus lesion, suggestive of the ethmoid origin, in 12 years until the age of 61 years. In the review of 20 patients with orbital myxomas in the literature, in addition to this case, roughly classified locations in the orbit were retrobulbar in 8 patients, on the lateral side of the orbit in 4, on the superior side in 6, on the medial side in 1 (this patient), and in the orbit with no specific description in 2. In pathological examinations, immunohistochemistry was not done in 8 patients, done but all negative in 2, and positive in 11 patients: nerve sheath myxoma was diagnosed in 3 patients based on positive S100 staining. Orbital myxoma is rare but considered in differential diagnosis of orbital masses.

An 89-year-old male presented with syncope and worsening difficulty in breathing through the left nostril. Computed tomography demonstrated a tumor in the anterior ethmoid air cells and maxillary sinus, which extended into the frontal lobe. Magnetic resonance imaging similarly demonstrated an aggressive lesion. This mass was difficult to differentiate from more commonly seen lesions at this location such as an esthesioneuroblastoma or nasopharyngeal carcinoma. Direct visualization, biopsy, and subsequent pathologic analysis eventually confirmed the diagnosis of malignant Ewing sarcoma (EWS). Our case explores the radiological findings of EWS originating from the ethmoid sinus, compares EWS with other common carcinomas in the same location, confirms the diagnosis through pathological correlation, and investigates the prognosis and treatment of these lesions. This case highlights the importance of a multidisciplinary approach to diagnose EWS when it occurs in an atypical location. The clinical team relied on input from the radiology, surgery, ENT, neurology, and pathology departments to make an accurate diagnosis and plan treatment for this aggressive tumor.

BACKGROUND SMARCB1-deficient sinonasal carcinoma is a rare neoplasm with inactivation of the SWI/SNF complex, with an aggressive clinical course as most of the lesions present as advanced in pT3/T4 stages with frequent recurrence, and many patients succumb to the disease. Reported initially in 2014, the lesion has male predominance, with an age range of 19 to 89 years and predilection for the ethmoid sinus and nasal cavity. Histopathological findings show a proliferation of small- to medium-sized monomorphic basaloid cells with indistinctive cytoplasmic borders and round variably prominent nuclei with scattered cells that show rhabdoid morphology. Cytoplasmic vacuoles are common. It has similar morphological findings to a wide array of neoplasms in the sinonasal area. CASE REPORT We report a case of SMARCB1-deficient sinonasal carcinoma in a 30-year-old man referred to our hospital with a preliminary diagnosis of sinonasal adenocarcinoma, intestinal type. Computed tomography showed a huge destructive soft tissue mass in the left maxillary sinus, extended to involve the left nasal cavity with extension to the skull base and perineural spread along the foramen rotundum. Histological examination revealed a malignant basaloid neoplasm embedded in a myxoid stroma that showed loss of SMARCB1 stain. The patient was treated with induction chemotherapy using etoposide and cisplatin for disease control. CONCLUSIONS SMARCB1-deficient sinonasal carcinoma is a rare neoplasm with an aggressive clinical course and high-grade behavior despite having uniform cytological features. This poses complex diagnoses, especially in small biopsies. Incorporating morphological findings with ancillary tests is required to identify this high-grade malignancy.

BACKGROUND: Osteomas of the paranasal sinuses occur rarely in the pediatric population, we find only a few reference of symptomatic osteomas in the literature. Opinions on the indication for surgical treatment are controversial.
METHODS: The authors present a case of symptomatic osteoma of the right ethoimoidal sinus in a 12-year-old boy, who was treated surgically, with endoscopic endonasal approach. The symptomatology, diagnosis and therapy of these tumors in the pediatric patient are discussed.
CONCLUSIONS: Osteomas of the paranasal sinuses are slow-growing benign lesions. Symptomatic osteomas can grow expansively and cause serious complications. The treatment of osteoma is surgical and the endoscopic approach offers the possibility of removal with cosmetic benefits.