This case report highlights a young male patient with Lynch syndrome who developed a rare adrenocortical carcinoma (ACC) alongside colorectal cancer, emphasized by loss of MSH2 and MSH6 protein expression in both tumors. The association between Lynch syndrome and ACC is critical for identifying at-risk individuals, influencing screening decisions, and evaluating adrenal nodules in patients with Lynch syndrome. Notably, this report is the first to associate oncocytic ACC with Lynch syndrome, underscoring the need for further exploration of this relationship.