Isolated orbital mass as the primary presentation of a triple-hit lymphoma transformed from a systemic follicular lymphoma

PURPOSE: Triple-hit lymphoma is a highly aggressive B-cell lymphoma. We report a case of triple-hit lymphoma transformed from systemic follicular lymphoma (FL) after 9-year remission and presented primarily as an isolated orbital mass without systemic symptoms or lymphadenopathy. OBSERVATIONS: A 58-year-old female presented with intermittent vertical binocular diplopia, left upper eyelid swelling and pain and was found to have a 2.9 cm orbital mass. Histological section revealed a CD10-positive large B-cell lymphoma, consistent with transformation of FL. Fluorescent in situ hybridization (FISH) analysis demonstrated rearrangements involving C-MYC, BCL-2 and BCL-6 genes, indicating a high grade, triple-hit lymphoma. CONCLUSIONS AND IMPORTANCE: Triple-hit lymphoma transformed from a low-grade lymphoma may initially present as an isolated orbital mass without systemic evidence of transformation. Early recognition of double or triple-hit lymphomas is important since these patients require aggressive chemotherapy.