Endocrine Abstracts

Introduction: Primary adrenal lymphoma (PAL) is a very rare entity. Less than 200 cases have been reported. Its evolution is unfavourable even under treatment. We report a case of PAL with a falsely reassuring course unmasked by 18F-FDG PET-CT.

Observation: This is a 48-year-old female patient hospitalized with altered general condition, weight loss, fever and cytopenias. The initial thoraco-abdomino-pelvic CT scan revealed two large bilateral adrenal tumour masses (18×13.7×9.8 cm on the left, 10×9.7×5.5 cm on the right). An adrenal insufficiency was confirmed and treated. CT-guided adrenal biopsy concluded to be a diffuse large cell B lymphoma. The patient received 4 courses of chemotherapy (R-CHOP). Post-chemotherapy thoraco-abdomino-pelvic CT scan showed moderate regression of the adrenal masses (12.7×11×7 cm on the left, 9×8×6.2 cm on the right) with an estimated partial response of 62% (Cheson criteria). In view of the discrepancy between radiological improvement and persistence of clinical alteration, a complementary 18F-FDG PET-CT scan ruled in favour of a metabolic progression (Deauville score=5): two intense hypermetabolic adrenal foci (SUVmax=20. 68 on the left, 15.12 on the right) with locoregional invasion of the psoas (SUVmax=12.64), external oblique (SUVmax=17.45) and pectoralis major (SUVmax=6.93) muscles. The patient died 6 months later.

Discussion: 18F-FDG PET-CT has become the reference imaging technique for the evaluation of lymphoma extension and therapeutic response. Our case illustrates this superiority since the therapeutic response described on PET-CT was more compatible with the actual clinical evolution of the patient.