[Bilateral choroidal osteoma in an aged patient].

The authors report a case of choroidal osteoma in an elderly patient. The affection was bilateral and multifocal. This rare benign tumor mostly affects young females. We report the outcome of the clinical and instrumental examinations leading to the diagnosis of choroidal osteoma. The patient underwent retinal fluoroangiography, A and B-scan ocular ultrasonography, Computerized Axial Tomography (CAT) with and without dye, orbit RNM, and electroretinography. The same investigations were performed 6-7 months after the first control. No changes in the findings were found except for retinal fluoroangiograms that revealed an increased area of the most central lesion in the right eye. Particularly relevant among these diagnostic techniques were ocular ultrasonography and CAT, which revealed the osseous nature of the tumor. Contact B-scan ultrasound examination showed a small number of dense opacities in both eyes. In the retrobulbar area the tumor caused diminution in echo amplitude. A-scan examination showed high reflectivity peaks (100%) corresponding to the lesion that were detectable even with reduced sensitivity of the system and, in the orbit, low reflectivity that confirmed the tumor's enhanced ultrasound absorption. CAT detected small calcified areas corresponding to the location of the lesions. Haematochemical examinations performed at each control to measure blood calcium, phosphate and alcaline phosphatase were in the normal range. Urinalysis also excluded possible systemic affections underlying the chorioretinal pathology. We discuss possible pathogenetical hypothesis focusing on the age and sex of the patient. These factors in fact, rule out both the hypothesis of a osteogenesis inhibiting factor present in the last 20-30 years of age and the hypothesis of endocrine stimulation in female patients.(ABSTRACT TRUNCATED AT 250 WORDS)