In this report, we present a rare case of childhood ALL with hypercalcemia and extensive osteolytic lesions. The case was a 7-year-old girl presenting with vomiting and aggravating bone pain. Radiologic examinations showed severe osteolytic lesions of the skull and extremities. Laboratory findings revealed low hemoglobin, normal WBC count with absent circulating blasts, and an increased serum calcium level. Serum intact PTH and 1,25-(OH)2 vitamin D3levels were below the normal ranges and parathyroid hormone-related peptide (PTHrP) was not detected, whereas serum levels of prostaglandin E2 were elevated. The hypercalcemia resolved with specific antileukemic chemotherapy along with supportive care. The elevated plasma prostaglandin E2 levels decreased slightly after complete remission with induction chemotherapy. These findings suggest that increased plasma prostaglandin E2 levels may be one of the pathogenetic mechanisms responsible for the occurrence of hypercalcemia in this patient.

Keywords: Acute lymphoblastic leukemia, Prostaglandin E2, Hypercalcemia, Osteolytic lesion