Malignant Langerhans cell tumor: a case with a favorable outcome associated with the absence of blood dendritic cell proliferation.

Malignant Langerhans cell tumor is a rare malignant proliferation of Langerhans cells, with a negative prognosis due to its dissemination throughout the body, leading to death within 1 year. This disease has to be distinguished from Langerhans cell histiocytosis. The favorable evolution of a case of Langerhans cell tumor, characterized by the absence of metastasis 18 months after its occurrence, may be due to the initial treatment, which consisted of complete and large resection of the tumor. The authors searched for abnormal dendritic cells or progenitors in the blood but found no large amounts or proliferation of CD34(+) or CD1a(+) cells at the diagnosis and 1 year later. This case report shows that malignant Langerhans cell tumor is not always a lethal disease. The condition may be related to surgical treatment and the absence of malignant cells in the blood when the diagnosis was performed.