Long-term outcome of primary endocrine non-Hodgkin lymphomas: does the site make the difference?

Primary lymphomas of endocrine glands are extremely rare. Our study adds more data to the few published series regarding the incidence, clinical characteristics, management and overall survival (OS) by comparing the various diffuse large B-cell endocrine lymphomas. Moreover, it contributes to a better understanding of these neoplasms and provides concepts for future research.

We retrospectively evaluated the clinical profile and the patterns of outcome among patients who were treated in our center with the diagnosis of aggressive, B-cell, primary endocrine lymphoma.

Between May 1980 and December 2011, 450 patients were diagnosed as primary extranodal non-Hodgkin lymphomas. Among them, 18 cases (4%) were primary testicular lymphoma (PTL), 8 cases (2%) were primary thyroid lymphoma (PTHL) and 4 cases (1%) were primary adrenal lymphoma (PAL). The therapeutic approaches employed were variable, including mainly chemotherapy in combination with radiotherapy and surgery. The median OS for the patients with PTL and PAL was 27 and 6 months, respectively. Better outcome was observed in patients with PTHL for whom the median OS has not been reached yet, whereas the PAL group had the worst prognosis.

The discrepancies in the outcome among endocrine lymphomas could be partly attributed to their biologic variability, which might be determined by the initial site involved. We conclude that treatment decisions should be made according to a multi-disciplinary approach to avoid unnecessary surgery. Existing treatment strategies for PTL and PAL fail to provide long-term survival, rendering the application of novel therapeutic approaches essential.