Congenital self-healing reticulohistiocytosis presented with multiple hypopigmented flat-topped papules: a case report and review of literatures.

Congenital self-healing reticulohistiocytosis, also known as Hashimoto-Pritzker disease, is a single system Langerhans cell histiocytosis that typically presents in healthy newborns and spontaneously regresses. In the present report, we described a 2-month-old Thai female newborn with multiple hypopigmented flat-topped papules without any internal organ involvement including normal blood cell count, urinary examination, liver and renal functions, bone scan, chest X-ray, abdominal ultrasound, and bone marrow biopsy. The histopathology revealed typical findings of Langerhans cell histiocytosis, which was confirmed by the immunohistochemical staining CDla and S100. Our patient's lesions had spontaneously regressed within afew months, and no new lesion recurred afterfour months follow-up.