Osteoid osteoma of the ethmoid bone associated with dacryocystitis

We report a case of a 16-year-old boy suffering from persistent epiphora and a mild pain in the area of median canthus, due to a bone density mass within the right ethmoid air cells extending to the ipsilateral right orbit. The mass was removed via an external ethmoidectomy approach. Histopathologic examination of the specimen set the diagnosis of OO. One year after the operation the patient is free of symptoms, while no recurrence occurred.A case of ethmoid bone OO associated with dacryocystitis is reported. Although benign and rare, OO should be considered in differential diagnosis of the ethmoid bone osteoblastic lesions.Osteoid osteoma was firstly described by Jaffe in 1935. It is a small, benign osteoblastic tumor, comprising 12% of the benign osseous tumors. Osteoid osteoma is characterized by varying intermixtures of osteoid, newly formed bone, and highly vascular supporting osseous tissue (nidus) surrounded by a distinctive surrounding zone of reactive bone formation. The nidus typically measures less than 1.5 cm in diameter [1].Osteoid osteoma most commonly (75%) occurs between 5 and 25 years of ages, with the majority of cases being the 2nd decade of life, while it is distinctively rare above the age of 30. There is a male predominance, with a 2–3:1 male to female ratio. Osteoid osteomas occur most commonly in the femur (27.33%), tibia (22.1%) and spine (10%) [1-3]. The less frequent sites of involvement are the ribs, the mandible and the calvarium [1].We report a very rare case of an ethmoid bone osteoid osteoma associated with dacryocystitis. The clinical, radiological, and pathological features are addressed.A 16-year-old boy was referred to our department by his ophthalmologist. He was suffering from persistent epiphora for about one year, which had been diagnosed as chronic dacryocystitis due to right nasolacrimal duct obstruction, while he had undergone probing of the right nasolacrimal duct once, by his ophthalmologist. The patient also referred a m