Adrenal incidentalomas originally defined as tumors discovered serendipitously in the course of diagnostic evaluation or follow-up of unrelated disorders, may occasionally pose serious diagnostic challenges. Intravascular large B-cell lymphoma (IVLBCL) may be a rare example of such a case. We present an IVLBCL confined to the adrenal gland in a 52-year-old man focusing on its diagnostic and therapeutic aspects. On endocrine work up, the tumor was hormonally inactive and exhibited inconclusive imaging characteristics without signs of locoregional spread. After a left laparoscopic adrenalectomy, histologic sections revealed the presence of tumor cells inside dilated, thin-walled vascular spaces. Immunohistochemical stains confirmed the diagnosis of IVLBCL. The patient was then referred to a Hematology Unit for further staging and treatment and received six cycles of R-CHOP. Despite the fact that IVLBCL carries a dismal prognosis our patient remains alive and in complete remission 6 years after the initial diagnosis.