We sought to refine the clinical picture of primary adrenal lymphoma (PAL), a rare lymphoid malignancy with predominant adrenal manifestation and risk of adrenal insufficiency.
Ninety-seven patients from 14 centers in Europe, Canada and the United States were included in this retrospective analysis between 1994 and 2017.
Of the 81 patients with imaging data, 19 (23%) had isolated adrenal involvement (iPAL), while 62 (77%) had additional extra-adrenal involvement (PAL+). Among patients who had both CT and PET scans, 18FDG-PET revealed extra-adrenal involvement not detected by CT scan in 9/18 cases (50%). The most common clinical manifestations were B symptoms (55%), fatigue (45%), and abdominal pain (35%). Endocrinological assessment was often inadequate. With a median follow-up of 41.6 months, 3-year progression-free (PFS) and overall (OS) survival rates in the entire cohort were 35.5% and 39.4%, respectively. The hazard ratios of iPAL for PFS and OS were 40.1 (95% CI: 2.63–613.7, P = 0.008) and 2.69 (95% CI: 0.61–11.89, P = 0.191), respectively. PFS was much shorter in iPAL vs PAL+ (median 4 months vs not reached, P = 0.006), and OS also appeared to be shorter (median 16 months vs not reached), but the difference did not reach statistical significance (P = 0.16). Isolated PAL was more frequent in females (OR = 3.81; P = 0.01) and less frequently associated with B symptoms (OR = 0.159; P = 0.004).
We found unexpected heterogeneity in the clinical spectrum of PAL. Further studies are needed to clarify whether clinical distinction between iPAL and PAL+ is corroborated by differences in molecular biology.