Objective: Adrenal lymphoma is a rare and aggressive form of non-Hodgkin lymphoma (NHL). We report 2 cases of adrenal lymphoma: one with typical symptoms of adrenal insufficiency, the other with the unusual presentation of symptomatic hypercalcemia from 1,25-dihydroxyvitamin D (1,25-[OH] 2-D) excess. Methods: A comparison of the clinical presentation of 2 patients diagnosed with primary adrenal diffuse large B cell lymphoma (DLBCL) treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) is reported. Results: The first patient was a 72-year-old man who presented with weight loss, hypotension, and bilateral adrenal masses. He was diagnosed with adrenal insufficiency from stage IVB DLBCL with primarily adrenal involvement. Treatment with 6 cycles of R-CHOP led to near-complete regression of adrenal masses and clinical remission, but with continued need for adrenocortical hormone replacement. He eventually succumbed to recurrent DLBCL with brain metastasis. The second patient was a 65-year-old man who presented with nausea, vomiting, constipation, and weight loss. He was noted to have hypercalcemia due to elevated serum 1,25-(OH) 2-D, bilateral large adrenal masses, but normal serum cortisol. He was diagnosed with stage II DLBCL. Treatment with R-CHOP led to complete remission with resolution of hypercalcemia. Conclusion: Primary adrenal DLBCL is an aggressive and rare type of NHL. While adrenal insufficiency is expected in this clinical scenario, hypercalcemia from 1,25-(OH) 2-D excess is an uncommon presentation. R-CHOP treatment may improve outcomes but more studies are needed to establish the optimal treatment for this rare disease entity. (AACE Clinical Case Rep. 2017;3:e307-e312) Abbreviations: 1,25-(OH) 2-D = 1,25-dihydroxyvitamin D; CNS = central nervous system; CT = computed tomography; DLBCL = diffuse large B cell lymphoma; FDG = fluorodeoxyglucose; HU = Hounsfield units; MRI = magnetic resonance imaging; NHL = non-Hodgkin lymphoma; PAL = primary adrenal lymphoma; PET = positron emission tomography; PTH = parathyroid hormone; PTHrP = parathyroid hormone-related peptide; R-CHOP = rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone; SUVmax = maximum standardized uptake value e308 The Diversity of Adrenal Lymphoma, AACE Clinical Case Rep. 2017;3(No. 4)