Background: Lymphomatoid papulosis (LyP), uncommon in children, has a benign clinical course in contrast with a malignant histology.
Case report: A 9-year old boy developed nodular skin lesions for 6 months on the scalp and penis and a papule skin on his trunk. Surgical excision of scalp nodules was performed to prevent necrosis and ulceration of the ear. The biopsy showed a dense mixed cellular infiltrate including histiocytes, lymphocytes and numerous atypical large cells of which a minority expressed the CD30 antigen. PCR showed an oligoclonal rearrangement of the TCR gamma chain gene. Physical examination, bone marrow aspirate and thoracoabdominal CT scans were normal. Three years after surgery, no other lesions occurred.
Discussion: Differential diagnosis of LyP is difficult with non Hodgkin's lymphoma, especially CD30+ lymphoma. Prognosis remains the major problem in LyP. Ten to 20% of cases are associated with lymphomas in adults.