Optical Coherence Tomography of Small Retinoblastoma

Area of Science:

• Ophthalmology
• Medical Imaging
• Oncology

Background:

• Retinoblastoma is the most common primary intraocular malignancy in children.
• Early detection and characterization of small retinoblastomas are crucial for effective treatment and vision preservation.
• Sub-millimeter retinoblastomas present diagnostic challenges with conventional imaging.

Purpose of the Study:

• To characterize the features of small (less than 1 mm thickness) retinoblastomas using hand-held optical coherence tomography (HH-OCT).
• To determine the layer of origin and identify specific HH-OCT findings associated with these small tumors.

Main Methods:

• Retrospective observational case series analyzing data from 15 patients with 20 sub-millimeter retinoblastomas.
• Hand-held optical coherence tomography (HH-OCT) scans were used to assess tumor dimensions and features.
• Layer-by-layer analysis of HH-OCT data was performed to determine the tumor's origin and describe characteristic signs.

Main Results:

• Mean tumor thickness was 468 μm, with a mean basal diameter of 2.2 mm.
• Retinoblastomas disrupted inner nuclear (INL), outer plexiform (OPL), outer nuclear (ONL), and external limiting membrane (ELM) layers.
• Characteristic HH-OCT findings included intratumoral microcalcification (70%), INL "fish tail" sign (95%), and ONL "shark fin" sign (75%).

Conclusions:

• Sub-millimeter retinoblastoma appears to originate from the INL, showing a linear relationship between tumor base and thickness.
• HH-OCT is valuable for identifying characteristic signs of small retinoblastomas, including microcalcification, the INL "fish tail" sign, and the ONL "shark fin" sign.