Montage Error in Ultra-Widefield Imaging of Retinal Hemangioblastomas

A 20-year-old male presented with three large retinal hemangioblastomas in the left eye. At the 5-week follow-up, automated montage ultra-widefield imaging appeared to demonstrate a fourth lesion, suggesting possible disease progression. Clinical examination, however, confirmed the presence of only three tumors. Re-evaluation of the automated image stitching revealed misidentification of the optic nerve head in one of the source images, resulting in image misalignment and the false appearance of an additional lesion. Systemic evaluation demonstrated central nervous system hemangioblastomas and a renal cyst, and genetic testing confirmed von Hippel-Lindau disease. This case illustrates both the diagnostic utility and limitations of ultra-widefield montage imaging and highlights the importance of clinical verification of apparent lesion increase before concluding true progression.