Langerhans cell sarcoma with an aberrant cytoplasmic CD3 expression

http://www.diagnosticpathology.diagnomx.eu/vs/2065486371761991 webciteAccording to the most recent WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2008) [1], Langerhans cell sarcoma (LCS) belongs to the category of histiocytic and dendritic cell neoplasms. It is a rare subtype of tumors derived from Langerhans cells with a female predominance.Clinically, LCS is often an extranodal tumor with skin and bone involvement, but it may present with multi-organ involvement including lymph node, lung, liver and spleen. 11% of the reported cases patients had pancytopenia. Compared to more commonly known Langerhans cell histiocytosis (LCH), also a clonal neoplastic proliferation of Langerhans cells, LCS has a much higher degree of cytological atypia and prominent proliferation rate with an aggressive clinical course. Both LCH and LCS have a similar immunophenotype including CD1a/langerin/S100+ [2,3] but without B- and T-cell lineage markers except for CD4 [4]. LCS with a cytoplasmic T cell specific marker CD3 has heretofore not been reported in the English literature. Herein we provide the first report of LCS with an aberrant cytoplasmic CD3 expression.An 86？year old Caucasian male who had been relatively healthy with medically controlled diabetes on insulin, treated temporal arteritis and myocardial infarction in 1987 without ongoing angina was referred to hematology/Oncology service for possible T cell lymphoma at Ottawa Hospital in July 2011. The patient had a short history of a rapidly growing right neck mass, an anemia of unknown cause, mild weight loss and generalized weakness. Laboratory investigations showed a bicytopenia with a normocytic anemia, Hb 89？g/L (reference interval 115–155？g/L) and thrombocytopenia, PLT 86 x 109/L (reference interval 125–400 x 109/L). He also had a neutrophilia with WBC 19.8 x 109/L (reference interval 3.0-10.5 x 109/L). LDH was mildly elevated with a value of 240 u/L(reference interval 100–205 u/L). CT of neck/thorax/ab