Cushing syndrome related to leukemic infiltration of the central nervous system

Cushing syndrome (CS) due to central nervous system (CNS) infiltration of hematological malignancy is a rare finding.

A 6.5-year-old boy with B cell acute lymphoblastic leukemia (ALL) came with excessive weight gain, headache, and irritability over last 2 months. CNS was not involved at diagnosis of ALL. On examination, the child had central obesity, moon facies, and buffalo hump. His height was at 3rd-25th percentile, weight was at >97th percentile, and blood pressure was >99th percentile. Serum cortisol was high in morning (25 μg/dL), at 12 a.m. (19.3 μg/dL) and remained elevated (7.5 μg/dL) after overnight dexamethasone test. Examination of cerebrospinal fluid (CSF) revealed blast cells suggestive of CNS relapse. Our second case was a 2.5-year-old girl with precursor B cell ALL, came with complaints of excessive weight gain, and increased appetite over last 3 months. On examination, the child had Cushingoid facies with trunkal obesity. Blood pressure was normal. Serum cortisol at 8 a.m. (40.4 μg/dL), midnight (13.8 μg/dL), and after dexamethasone suppression test (22 μg/dL) was high. CSF examination showed blast cells. We diagnosed both cases with adrenocorticotropic hormone-dependent CS due to CNS relapse based on the above findings.

We have reported two cases of CS due to CNS relapse of ALL. CS is a very rare manifestation of CNS relapse in patients with leukemia, and the exact pathogenesis is not clear.