Langerhans cell sarcoma: a case report.

Primary cutaneous neoplasms of histiocytes and dendritic cells are rare. Langerhans cells are a subset of antigen-presenting dendritic cells. Neoplasms of Langerhans cells are classified into cytologically benign Langerhans cell histiocytosis and cytologically malignant Langerhans cell sarcoma. Langerhans cell sarcoma is a rare entity characterized by multiorgan involvement and an aggressive clinical course. To date, only 30 cases of Langerhans cell sarcoma, including the present case, have been reported. We report a new case of Langerhans cell sarcoma that presented with multifocal cutaneous involvement. Diagnosis was done based on histopathological, immunohistochemical evaluation, as well as ultrastructural analysis identifying the presence of Birbeck granules. Our case represents a new case of this extremely rare, overtly aggressive neoplasm of Langerhans cells. Within 2 years of diagnosis, the patient developed metastatic disease and consequently died. Early recognition is important because of the tendency of Langerhans cell sarcoma to recur and metastasize. Therefore, ancillary techniques such as immunohistochemical and ultrastructural studies to confirm the diagnosis are very advantageous.