PET/CT findings in a case with FDG-avid disseminated lacrimal gland MALToma with sequential development of large B-cell lymphoma and gastric MALToma.

Primary orbital lymphomas are rare; the major histopathologic type is extranodal marginal-zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) or MALToma. We present a case of a 79-year-old female patient with FDG-avid lacrimal gland MALToma with nodal and pulmonary involvement (stage IVE). Nasopharynx and gastric involvement were detected on restaging F-FDG PET/CT after rituximab therapy, and it was found to have a site of transformation to diffuse large B-cell lymphoma (DLBCL) in the nasopharynx. Gastric MALT lymphoma was also confirmed histopathologically, and she then underwent combination chemotherapy regimen, resulting in regression after 3 courses.