Primary Orbital MALT Lymphoma Associated with Localized Amyloidosis

ABSTRACT

PURPOSE: To report a case of primary orbital MALT lymphoma with localized amyloidosis. CASE SUMMARY: A 61-year-old male visited our clinic with diplopia, which had developed approximately 5 months earlier. Magnetic resonance imaging of the orbit showed an ill-defined well-enhanced mass in the left inferior orbit. Incisional biopsy of the orbital mass was performed. Histopathological examination revealed diffuse deposits of an amorphous, eosinophilic substance in the extracellular matrix and vessels with lymphocytes infiltration. Lymphocytes were positive for the immunohistochemical stain against the CD20 and kappa-light chain antigens. The amorphous material stained positive for kappa-light chain antigen, and Congo red staining showed birefringence. CONCLUSIONS: We report a rare case of primary orbital MALT lymphoma associated with localized amyloidosis.