Pulmonary manifestation of a Langerhans cell sarcoma: case report and review of the literature.

In the following, we describe the very rare case of Langerhans cell sarcoma (LCS) in the lung. Throughout the medical literature, only a few cases have been published, and, to the best of our knowledge, this is the first case to be reported in Germany. The patient was an 81-year-old man who showed symptoms such as chronic cough and weight loss. Clinical examination including needle biopsy indicated a high possibility of carcinoma in the right lung and in the mediastinum; however, the final histopathological diagnosis after immunohistochemistry gave evidence of LCS. LCS is a neoplastic proliferation of Langerhans cells with malignant cytological features exhibiting a very aggressive behaviour. LCS can be distinguished from other carcinomas, lymphomas and sarcomas by the typical morphological features of Langerhans cells and the immunophenotype with a consistent expression of S-100 protein and CD1a. In contrast to Langerhans cell histiocytosis, the LCS consists of Langerhans cells with high atypia and a very high mitotic rate.