To the Editors:
Lymphocyte activation in sarcoidosis and the involvement of the reticuloendothelial system (liver, spleen, lymph nodes) make differential diagnosis between sarcoidosis and lymphoma a difficult task. In an earlier epidemiological study, an 11-fold increase in lymphoma cases among patients with sarcoidosis was observed; however, the methodology of this study has been questioned 1–3. In order to elucidate the clinical characteristics of sarcoidosis and lymphoma, we conducted this retrospective review of cases of patients in which sarcoidosis and lymphoma coexisted in the same patient. These cases have been retrieved from our institution (University of Southern California, Los Angeles, CA, USA) and from an extensive Medline review.
Our inclusion criteria were: 1) biopsy-proven sarcoidosis, based on American Thoracic Society (ATS)/European Respiratory Society (ERS)/World Association of Sarcoidosis and Other Granulomatous Diseases (WASOG) criteria 4 applied by the authors retrospectively; 2) biopsy-proven lymphoma classified as Hodgkin Lymphoma (HL) and non-HL (NHL) according to the World Health Organization (WHO) classification 5. Exclusion criteria were diagnosis of other malignancies and sarcoid-like reactions (SLR). These reactions, secondary to malignancies, are considered to occur either adjacent to the primary malignant site or to local drainage nodes. Group A consisted of cases in which sarcoidosis preceded lymphoma; group B consisted of cases in which the two diseases presented concurrently (in a period <1 month); and, in group C, lymphoma preceded sarcoidosis.
The primary end-point was to clarify the symptoms and signs 1) of lymphoma in a patient already diagnosed with sarcoidosis and 2) of sarcoidosis in a patient already diagnosed with lymphoma. We compared initial sarcoidosis presentation (group A) with initial lymphoma presentation (group C); then, sarcoidosis as the second disease (group C) with lymphoma as the second disease (group A). Our secondary end-point …
