Sarcoidal granulomas in the mediastinal lymph nodes after treatment for marginal zone lymphoma of the esophagus: report of a case with review of the concept of the sarcoidosis-lymphoma syndrome.

Patients with sarcoidosis have a high risk of development of malignant lymphoma, and this association was coined the term "sarcoidosis-lymphoma syndrome". Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct clinicopathological entity, and the stomach is the most common site. The occurrence of this type of lymphoma in the esophagus is extremely rare. In this report, we describe the first documented case of sarcoidal granulomas in the mediastinal lymph nodes after treatment for MALT lymphoma of the esophagus. A 60-year-old Japanese female was found to have a submucosal tumor in the esophagus. Histopathological study revealed proliferation of small- to medium-sized lymphoid cells with convoluted nuclei, and immunohistochemically, these lymphoid cells were diffusely positive for CD20, bcl-2, and MUM1. R-CHOP therapy was performed, which led to tumor remission. Two years later, swelling of the mediastinal lymph nodes was detected. Histopathological study of the lymph nodes revealed presence of variably-sized epithelioid granulomas without caseating necrosis but no malignant lymphoma was noted. Sarcoidal granulomas can be observed in patients with malignant tumors including malignant lymphoma and carcinoma without history of systemic sarcoidosis. It is important to recognize that systemic sarcoidosis and sarcoidal reaction without evidence of systemic disease can occur after development of malignant lymphoma, therefore, sarcoidal reaction must be included in the differential diagnostic consideration of recurrent malignant lymphoma.