Primary Adrenal Gland Lymphoma: Report of 13 Cases—A Retrospective Multicenter Polish Lymphoma Research Group Analysis

<b>Introduction:</b> The existence of primary adrenal gland lymphoma (PAGL) has been debated due to lack of lymphoid tissue in the adrenal glands. PAGL is extremely rare, accounting for less than 1% of all types of lymphomas. The aim of this study was to analyze patients with PAGL in Polish population. <b>Material and Methods:</b> We retrospectively reviewed 13 adult patients with PAGL diagnosed in Polish Hematological Centers. <b>Results:</b> A total of 13 patients (5 women and 8 men) with PAGL were included into the study. The median age at the diagnosis was 69.1 years (range: 31-85). The most common histological type was diffuse large B-cell lymphoma (DLBCL)-12 patients, the remaining one was diagnosed with Hodgkin lymphoma (HL). In 7 patients (54%), the left adrenal gland was involved; in 3 patients (23.5%), the right adrenal gland was involved; and 3 patients (23.5%) had bilateral lymphoma. Systemic symptoms (B symptoms) were observed in 11 out of 13 patients (85%). Two patients (15%) were treated with chemotherapy alone and the remaining eleven patients (85%) with immune and chemotherapy together (85%). During the follow-up period, 11 patients died, 8 had relapsed or refractory disease (62%), and 3 patients (23%) had relapse in central nervous system (CNS). The median progression-free survival (PFS) was 14.63 months, while the median overall survival (OS) was 20.30 months. Adrenalectomy of the involved adrenal gland was associated with shorter PFS (<i>p</i> = 0.0165), with trend of shorter OS. Achieving complete remission (CR) after front line treatment was associated with significantly longer OS (<i>p</i> = 0.0239) and PFS (<i>p</i> = 0.0152). <b>Conclusions:</b> Adrenal glands are extremely rare as primary locations of extranodal lymphoma. The prognosis of PAGL is generally poor. In this study, we described demographic, clinical, and pathological characteristics as well as factors that may affect survival among these groups. So far, it is the largest polish multicenter experience describing patients with PAGL.