Histiocytic sarcoma of the neck: A case report.

Histiocytic sarcoma (HS) is a term used to describe malignant hyperplasia of cells exhibiting morphological and immunophenotypical characteristics similar to those of mature cells, with expression of one or more tissue cell markers, excluding acute monocytic leukemia and primitive monocytic sarcoma. We herein describe a case of histiocytic sarcoma of the neck supported by histopathological and immunohistological evidence. A 53-year-old female patient of Chinese descent presented with a rapidly enlarging right neck mass. Imaging studies revealed multiple right cervical lymphadenectases with right jugular vein involvement. The tumor was composed of diffusely distributed large non-cohesive tumor cells, round or oval and focally spindle-shaped. The tumor cells were immunopositive for macrophage-associated antigen CD68 and lysosomes, mostly consistent with a diagnosis of HS. HS is very prone to systemic metastasis; therefore, early diagnosis and timely treatment are crucial.