Background:

Non-Hodgkin lymphomas are heterogeneous neoplasms derived from lymphohematopoietic cells, which are rarely found in children < 2 years of age and have a higher prevalence in males.

Case report:

One-year and eleven-month-old male patient started with pain in the lower and upper limbs, intermittent claudication, bone deformity, and generalized hypotonia, for which juvenile arthritis was suspected. He received non-steroidal anti-inflammatory drug treatment. As no improvement was reported, he was admitted in a different hospital with lymph nodes and nodulations in the scrotal and brachial region and hepatomegaly. Therefore, early activation of puberty with evidence of hypercalcemia was presumed. Radiological studies indicated possible bone dysplasia; however, positron emission tomography detected areas compatible with malignant process. Precursor B lymphoma was diagnosed. Hypercalcemia is a metabolic disorder considered a paraneoplastic syndrome in the presence of cancer, which is an exceptional clinical finding in children with acute lymphoblastic leukemia.

Conclusions:

Bone pain in the pediatric age deserves a thorough physical examination to favor an early diagnosis of childhood cancer and a better prognosis.