A case of Langerhans' cell histiocytosis associated with Hodgkin's lymphoma: Fine-needle aspiration cytologic and histopathological features.

Langerhans cell histiocytosis (LCH) can be associated with a variety of malignant neoplasms, the most common being malignant lymphoma, especially Hodgkin's lymphoma (HL). In this report, we describe the fine needle aspiration (FNA) cytologic features of a case with concurrent LCH and HL in a lymph node. A 20-year-old man presented with an enlarged left upper cervical lymph node. FNA smears from the swelling revealed numerous CD1a+ and S-100+ Langerhans-type cells (LCs) along with many eosinophils, neutrophils, and lymphocytes; there were also large atypical cells with enlarged nuclei having prominent nucleoli. The cytodiagnosis was LCH and the possibility of association with or trans-differentiation into a lymphoma was suggested. The histopathological diagnosis of the excised left cervical lymph node was classical HL-nodular sclerosis type (CHL-NS) with LCH. The lacunar type Reed-Sternberg (RS) cells were positive for CD30 and CD15, and the LCs were positive for CD1a and S-100 protein. PET/CT imaging demonstrated hypermetabolic lymph nodes in neck, abdomen, thorax and pelvis as well as pulmonary nodules and a splenic mass. The patient received 13 courses of chemotherapy and two years later, the enhanced CT revealed regressive course of the disease.