Do no harm: Observation only in a 98-year-old woman with a suspicious large intraocular tumour

A 98-year-old asymptomatic white female was referred with the incidental finding of a suspicious right iris mass. Medical history included treated hypertension and hypothyroidism. On examination, visual acuity was 20/60 in the right eye and 20/40 in the left eye. The left eye was structurally normal. In the right eye there was erosion of the iris root at the 1 o'clock position (Fig. 1). Through an undilated pupil, the edge of a pale mass with overlying pigment changes (Fig. 1) was visible. Intraocular pressure was 14mmHg. The iridocorneal angle was obscured by the tumour on gonioscopy, but there was no suspicious circumferential spread. She was pseudophakic and on transpupillary transillumination light was transmitted through the mass. Anterior chamber-optical coherence tomography demonstrated a mass located posterior to the iris (Fig. 1). B-mode ultrasound scan (14MHz) showed a bi-lobed tumour of medium internal echogenicity, an elevation of 4.8 mm and detectable internal blood flow (Fig. 1). Fundoscopy showed only age-related macular changes. The differential diagnosis included an iris naevus or melanoma, metastasis to the ciliary body or a medulloepithelioma, but also rarer tumours of the non-pigmented epithelium of the ciliary body, including a true adenoma, adenocarcinoma or a Fuchs adenoma. The management options included a diagnostic tissue biopsy, plaque brachytherapy, lesion excision, enucleation, or observation. Given the patient's age, general medical background and clinical features on eye examination, especially the light transmission properties on transillumination, the working clinical diagnosis was of Fuchs adenoma, a benign pseudotumour of the non-pigmented ciliary body epithelium. Observation after 6 months showed no progression of the lesion, supporting the original diagnosis.