Clinicopathological analysis of primary adrenal diffuse large B-cell lymphoma: effectiveness of rituximab-containing chemotherapy including central nervous system prophylaxis

Background: Primary adrenal lymphoma (PAL) is an extremely rare subtype of extranodal non-Hodgkin's lymphoma. Some researchers have reported some of the characteristics of PAL and its association with poor prognosis; however, the clinicopathological features of PAL remain to be elucidated. Methods: From 2008 to 2011 we experienced seven cases of PAL in our institutions. We retrospectively analyzed the clinical and pathological features of these patients. Results: The patients ranged in age from 50 to 85 years, with a median of 71 years. The overall male: female ratio was 6: 1. All seven patients were diagnosed with diffuse large B-cell lymphoma (DLBCL) pathologically. Bilateral adrenal involvement was confirmed in five patients. The median largest tumor diameter at diagnosis was 58 mm. The Ki-67 index was generally high (> 70%). All patients were treated with rituximab-containing chemotherapy, and central nervous system (CNS) prophylaxis was conducted for three patients. One patient with CNS involvement at the time of the diagnosis also received whole-brain radiation. The overall survival rate at two years was 57% (median follow-up; 24.8 months). It is noteworthy that the three patients who received a full course of the rituximab-containing regimen and CNS prophylaxis are currently alive without disease relapse, and that none of the seven patients died due to progression of lymphoma. Conclusions: Primary adrenal DLBCL can be a clinically aggressive disease entity. Rituximab-containing chemotherapy combined with CNS prophylaxis could be a reasonable option for the treatment of PAL; however, analyses of more PAL cases are needed for the establishment of this strategy.