A case of pulmonary langerhans' cell histiocytosis mimicking osteosarcoma pulmonary metastases (clinical case)

Langerhans cell histiocytosis is a clonal neoplastic process characterized by cell proliferation of the Langerhans type, with the expression of CD1a, CD207 and S100 proteins and the presence of Birbek granules. We present a case of a 31-year-old woman with a verified osteosarcoma of the proximal epimetaphysis of the left tibia. Also she has multiple thin-walled cysts and foci in the lungs. The case is interesting for the rare combination of osteosarcoma of the bone and pulmonary histiocytosis. This case show that foci in lungs can simulates metastatic disease according to computed tomography (CT). Multidisciplinary approach of pathologist, oncologist and radiologist help revealed diagnose.

Pulmonary histiocytosis

Introduction. Langerhans cell histiocytosis encompasses a group of disorders of unknown origin with different clinical presentations and outcomes. It is characterized by infiltration of the involved tissues by large numbers of Langerhans cells, often organized into granulomas. The accumulation of these cells causes the classic lytic bone lesions, skin rashes, lymphadenopathy, splenomegaly, and dysfunction of organ such as the pituitary gland, lungs, liver, and bone marrow. Pulmonary histiocytosis. Adult pulmonary Langerhans cell histiocytosis is a rare disorder of unknown etiology. It occurs predominantly in male smokers, with an incidence peak between 20 and 40 years of age. High-resolution computed tomography of the chest can show nodules, cavitated nodules, and thickand thin-walled cysts. The definite diagnosis of pulmonary Langerhans cell histiocytosis requires identification of Langerhans? cell granulomas infiltrating and destroying distal bronchioles, which is usually achieved by lung biopsy at a site selected by chest high-resolution computed tomography. Treatment. Treatment options for adults have never been clarified by a clinical trial. The published literature provides minimal data on the comparative efficacy of various treatment options which include surgery/curettage, steroids, radiation, and various chemotherapy regimens. The improved understanding of the mechanisms involved in the pathogenesis of pulmonary Langerhans cell histiocytosis should help in the development of specific therapeutic strategies and effective treatment.