Systemic malignant lymphoma 17 years after bilateral orbital pseudotumor

Purpose: To report a patient who developed systemic malignant lymphoma 17 years after bilateral orbital pseudotumor. Case: A 24-year-old man developed bilateral orbital pseudotumor. He was stable until 17 years later, when he was afflicted with systemic malignant lymphoma, a diffuse large B-cell lymphoma, and he died of the disease. He showed no new orbital lesion at the presentation of systemic lymphoma. Pathological diagnosis at autopsy was systemic malignant lymphoma with bilateral orbital pseudotumor. Methods: Immunohistochemical reexamination of the paraffin-embedded tissue and polymerase chain reaction of paraffin sections. Results: Histopathologically, the orbital masses resected on different occasions consisted of small lymphocytes and plasma cells. Immunohistochemical staining revealed an immunoglobulin light chain κ and λ bitype of B-cell lymphocytes and plasma cells. In contrast, the cervical lymph node showed large lymphoma cells that were positive only for λ light chain, indicative of a λ monotype. Amplification by polymerase chain reaction of the immunoglobulin heavy chain gene from paraffin sections demonstrated clonal rearrangement in the cervical lymph node but showed no clonality in the orbital tumor, supporting altogether the diagnosis of orbital pseudotumor. Conclusion: Orbital pseudotumor should be carefully followed for possible development of systemic malignant lymphoma.