In this week’s issue

AJOCR

Summary written by Rahul Nanduri

Borrowing from the retinoblastoma playbook

A 1-month-old male presented with a left orbital mass, which was initially diagnosed as a capillary hemangioma. After a four-week trial of oral propranolol without any improvement, magnetic resonance imaging revealed an enlarging, lobulated, intraconal mass.

Biopsy and DNA methylation array analysis identified the lesion as an embryonal tumor with multilayered rosettes (ETMR), an aggressive neoplasm not previously reported in the orbit. Germline genetic testing revealed a DICER1 mutation, and the tumor itself harbored a second, distinct somatic DICER1 mutation, consistent with the “two-hit” mechanism. ETMR carries a poor prognosis, and no established treatment protocol exists for orbital involvement.

During discussions for the patient’s care plan, the family declined exenteration, and the care team instead offered intraarterial chemotherapy, an approach with no prior reported use in DICER1-mutated orbital ETMR (but well established for retinoblastoma). After four monthly outpatient treatment sessions, the mass regressed promptly, and serial imaging showed no recurrence at 23 months of follow-up, achieved without surgery, radiation, or systemic chemotherapy.

This case illustrates that intraarterial chemotherapy may offer an effective, vision- and life-preserving alternative for rare orbital embryonal tumors, and reinforces the value of germline DICER1 testing and methylation profiling in atypical pediatric orbital masses.

You are a resident on the cornea service when a 60-year-old woman is referred to your clinic for evaluation of corneal edema in the right eye and possible surgical management. Three years ago, she underwent cataract extraction of a dense nucleus with IOL implantation in the right eye. She tells you that her vision in that eye has progressively worsened since the time of surgery. Her eye is uncomfortable, but she denies new floaters, flashes of light, and any history of ocular trauma.  Vision is CF at 3 feet OD and 20/20 OS. Pachymetry is notable for a corneal thickness of 710 μm OD and 550 μm OS. The right cornea has subepithelial bullae on the superior third of the cornea, an irregular surface, and 2-3+ corneal edema. Slit lamp photograph is shown below.

What is the most likely diagnosis?

A. Fuchs’ endothelial dystrophy

B. Band keratopathy

C. Pseudophakic bullous keratopathy

D. Limbal stem cell deficiency

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