A rare anatomical malformation of the sphenoid sinus: A case report

Introduction: Sphenoid sinuses, air-filled cavities in the sphenoid bone, develop between the 3rd and 4th year and mature by 12 to 16 years. Understanding their anatomy is vital for safe transsphenoidal surgeries because of nearby vital structures. They exhibit variable pneumatization and often have an intersinus septum. This case emphasizes the importance of understanding sphenoid sinus anatomy, particularly in the context of transsphenoidal surgeries. It also introduces a novel case involving a congenital roof defect, previously unreported in medical literature. Case presentation: A 52-year-old male presented with left cheek swelling that progressed to the eyelid, accompanied by low visual acuity, nasal symptoms, and a high temperature. Clinical examination revealed purulent discharge. A CT scan indicated opacity in the left maxillary sinus and a roof defect in the left sphenoid sinus. However, endoscopic surgery revealed the sphenoid sinus to be normal. This indicates that the defect is congenital. A biopsy from the maxillary sinus lesion confirmed lymphoma, and he was sent to the oncology hospital. There was no extension of the maxillary sinus lesion into the sphenoid sinus. This unique case had no history of drainage, taste issues, meningitis, or pituitary surgery. Discussion: The complete absence of the sphenoid sinus roof is a unique and rare anatomical anomaly with significant implications for surgical procedures. Transsphenoidal surgery, which benefits from endoscopic advancements, provides enhanced visualization but also poses risks due to the proximity to critical structures. Pneumatization of the sphenoid sinus typically reaches maturity during adolescence, with individual variations in extent, Septations, extensions, and asymmetry are common in sphenoid sinus anatomy. This underscores the need for surgeon awareness and adjusted surgical approaches in such rare instances. Conclusions: We emphasize the importance of a thorough anatomical understanding through precise radiological study before any sinus surgery due to the possibility of unexpected anatomical abnormalities.