Secondary Choroidal Osteoma in the Setting of Uveal Pathology: 4 Case Reports and Review.

Introduction: Choroidal osteoma is a rare benign tumor where mature bone replaces the choroid. Possible causes include inflammation, trauma, hormones, disorders of calcium metabolism, environmental factors, genetics, or osseous choristoma. This paper discusses 4 cases and literature regarding choroidal osteoma occurring concurrently with or secondary to uveal pathologies including uveitis and pachychoroid spectrum.

Case presentations: In case 1, a 41-year-old man with central serous chorioretinopathy (CSCR) in both eyes (OU) developed a choroidal osteoma in the left eye (OS) 8 years after the initial visit. Type 1 macular neovascularization (MNV) developed 4 years later at age 53. In case 2, a 50-year-old woman with CSCR OU developed a choroidal osteoma OS 15 years after the initial visit. The lesion gradually enlarged over another 15 years of observation. In case 3, a 24-year-old woman with Vogt-Koyanagi-Harada disease treated with systemic corticosteroids for 6 months developed choroidal osteoma OU and type 2 MNV in the right eye (OD) 16 years after the initial visit. In case 4, a 55-year-old man with concurrent posterior scleritis and choroidal osteoma OS developed type 1 MNV 13 years after the initial visit. He had a history of unknown uveitis treated with high-dose corticosteroid therapy 21 years previously. In all 5 eyes, the presence of osseous tissue in the choriocapillaris and Sattler's layer was confirmed by optical coherence tomography, B-mode ultrasound, or computed tomography. These lesions demonstrated observed growth in basal diameter and/or maturation process of bone tissue throughout the follow-up period.

Conclusion: We observed 5 eyes of four patients with choroidal osteoma in the choriocapillaris and Sattler's layer of the choroid secondary to CSCR, Vogt-Koyanagi-Harada disease, or posterior scleritis over a long follow-up period of 12-30 years. Secondary choroidal osteoma, ectopic bone in the choroid, can result from the transformation of mesenchymal cells stimulated by osteoprogenitors, such as bone morphogenetic proteins. Secondary choroidal osteoma should be recognized as a rare long-term complication of uveal pathologies.