Clinical and ultrasonographic features of choroidal metastases based on primary cancer site: Long-term experience in a single center

Introduction and purpose Choroidal metastases (CM) are the most common intraocular malignancies. With longer survival rates for cancer patients, CM will be increasingly encountered. We evaluated clinical and ultrasonographic (US) characteristics of CM in order to identify diagnostic biomarkers that correlate with the primary tumor site. Methods The medical records of all patients with CM evaluated at the Ocular Oncology Unit between February 2010 and March 2020 were analyzed. Results 82 eyes of 70 patients were included. The primary cancer site was lung in 26 patients (37%), breast in 23 (33%), kidney in 9 (13%), gastrointestinal in 5 (7%), thyroid in 5 (7%), parathyroids and prostate respectively in 2 (3%). Fifty-five patients (78%) had other systemic metastases at the time of ocular diagnosis. Ten (14%) patients had no history of primary cancer. Bilateral CM were found in 20 patients (29%); fifty-six eyes (68%) had a single CM. The epicenter of CM was predominantly macula (43 eyes, 52%). The mean thickness was 4,1 mm (range 1,8-12,3). US structure was inhomogeneous in 67 eyes (82%). Reflectivity was mainly medium (39%) and medium-low (39%). In particular, CM from lung cancer showed lower reflectivity than those from the breast (p = 0,02). CM deriving from lung cancer were typically dome-shaped, whereas CM originating from breast were characteristically plateau shaped (p = 0,02). Seventy-four (91%) eyes presented fluid on optical coherence tomography. Conclusion We significatively found that CM from lung cancer generally appear dome-shaped with medium-low internal reflectivity, whereas those from breast cancer typically present a plateau appearance and higher internal reflectivity. Though it is hard to identify the site of the primary tumor relying exclusively on clinical and US aspects, morphology and internal reflectivity can be considered as diagnostic biomarkers. Thus, the origin of the primary tumor can be suspected by integrating a constellation of findings.