TY - JOUR T1 - Histiocytic sarcoma with bladder involvement: Case report and literature review JO - Revista Española de Patología T2 - AU - Fernández-Aceñero,Mª Jesús AU - Pérez Alonso,Pablo AU - Díaz del Arco,Cristina SN - 16998855 M3 - 10.1016/j.patol.2017.01.001 DO - 10.1016/j.patol.2017.01.001 UR - https://www.elsevier.es/es-revista-revista-espanola-patologia-297-articulo-histiocytic-sarcoma-with-bladder-involvement-S1699885517300065 AB - We report an unusual case of histiocytic sarcoma with bladder involvement. An 80 year-old man with a previous history of diffuse large B-cell malignant lymphoma presented with hematuria and back pain. Serial urine cytologies revealed no urothelial malignant cells, but cystoscopy showed a large intravesical mass. The patient underwent transurethral resection (TUR) of the tumor. The bladder TUR specimen showed a widely infiltrating epithelioid neoplasm, with intense immunohistochemical positivity for CD45 and histiocytic markers (CD68, lysozime and fascin). Histopathological diagnosis was histiocytic sarcoma. As the patient's condition was progressively deteriorating, only palliative care was indicated and he died one month after TUR. Although histiocytic sarcoma can often be widespread at the time of diagnosis, to our knowledge, this is the first report of a case presenting with urinary symptoms. Histiocytic sarcoma can mimic many other malignant lesions, and only immunohistochemistry can define the tumor cells, allowing correct therapy. We discuss the differential diagnosis and possible associations. ER -