Delayed recurrence of an iridociliary malignant melanoma 180° from the primary tumor

Purpose: We report the case of a 66-year-old female who returned with a rare recurrence of iridociliary melanoma 180° from the original lesion. Observations: Upon initial presentation eleven years prior, a pigmented iris lesion suspicious for primary uveal melanoma was noted in the right eye at 9 o'clock. After one year of observation, inferior growth of the iris lesion prompted treatment via primary iridectomy with excisional biopsy and pupilloplasty. Postoperative biopsy confirmed spindle B type melanoma with epithelial foci, and adjuvant brachytherapy was performed to treat the reported positive anterior ciliary body involvement. Ten years after initial plaque brachytherapy treatment, the patient returned with a pigmented iris lesion in the right eye at 3:30–5 o'clock, which was treated with enucleation. On pathology, the new melanoma was predominantly epithelioid, consistent with a transformed recurrent iridociliary melanoma. The patient remains metastasis free 13 years after initial diagnosis. Conclusions and importance: This case describes a rare, late recurrence of an iridociliary melanoma 180° away eleven years after initial presentation, emphasizing the importance of lifelong follow-up for patients with iridociliary melanoma. This rare form of recurrence has not been previously reported in the literature. We hypothesize the original lesion contained radiotherapy resistant epithelioid cells which grew superficially on the posterior iris and anterior ciliary body, ultimately breaking back through the anterior iris 180° away