Langerhans cell histiocytosis with spinal cord involvement in HIV-positive children: a case report

Langerhans cell histiocytosis (HCL) is a mainly pediatric disease whose severity is highly variable and clinical presentation depends on the site affected. Excluding craniofacial lesions, the spine is the most frequently involved bone site. A 5-year-old male, admitted to a tertiary hospital with a history of three weeks of low back pain, with irradiation of lower limb pain, which made walking difficult, with partial improvement after the use of anti-inflammatories. He denied traumas, fever or other symptoms during the period. On physical examination, he presented pain on palpation of the lumbar region, absence of skin lesions or other alterations. Previous HIV diag-nosis by vertical transmission, in irregular use of antiretroviral therapy (zidovudine, lamivudine, lopinavir, and ritonavir), with CD4+ cell count of 314/mm3 (12%) and viral load of 28,937 copies (log 4.46). Upon admission, he had normal blood count and high inflammatory activity tests. Computed tomography of the thoracolumbar spine showed destructive lesions of vertebral bodies of T4, T8, and L1. Patient was then submitted to vertebral biopsy, with anatomopatho-logical examination of the tissue, receiving the diagnosis of HCL. In the isolated sample of bone tissue, culture for bacteria and fungi and PCR for tuberculosis were negative. HCL is a disease of difficult suspicion and diagnosis, since its low incidence and nonspecific symptoms, common to many pathologies. For the described patient, HIV infection with high viral load and low concen-tration of CD4+ lymphocytes made the diagnosis even more challenging.