Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 5 2 2020 08 30 47 50 Marjan Mouodi Department of Pediatrics, Bahrami Children’s Hospital, Tehran University of Medical Sciences, Tehran, Iran. Soghra Rabizadeh Department of Pediatrics, Bahrami Children’s Hospital, Tehran University of Medical Sciences, Tehran, Iran. Hasan Jalaeikhoo AJA Cancer Research Center (ACRC), AJA University of Medical Sciences, Tehran, Iran. Manouchehr Nakhjavani Department of Pediatrics, Bahrami Children’s Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2019 12 10 2020 02 20 Acute Lymphoblastic Leukemia (ALL) is a type of leukemia that generates from white blood cells in the bone marrow. ALL could present with different nonspecific symptoms. Hypercalcemia is a rare presentation in B-cell ALL. We reported a middle-aged man presented with hypercalcemia and osteolytic bone lesions without bone pain and a definitive diagnosis of B-cell ALL. https://crcp.tums.ac.ir/index.php/crcp/article/view/321 https://crcp.tums.ac.ir/index.php/crcp/article/download/321/352