Histiocytic sarcoma is a rare malignant neoplasm exhibiting a morphological and immunophenotypic differentiation resembling mature histiocytes. It is an aggressive neoplasm, accounting for less than 1% of all hematological malignancies. The etiology of histiocytic sarcoma is largely unknown, but it has been associated with mutations in members of the MAPK and PI3K pathways. Histiocytic sarcoma more commonly occurs in adulthood, with no sex predominance and a propensity for lymph node involvement. Extranodal manifestations also occur, usually involving the gastrointestinal tract, skin, lungs, central nervous system, and liver. In the oral cavity, the neoplasm more commonly affects the soft and hard palate, but a local manifestation of a widespread disease should always be excluded. They often manifest as ulcered swellings with or without necrotic regions and bone destruction in the oral cavity. Microscopically, histiocytic sarcoma presents with a diffuse growth pattern of large polygonal tumor cells with abundant cytoplasm showing a clear or foamy-like appearance. Positivity to CD68, CD163 and lysozyme are the most typical immunohistochemical features of this neoplasm. There is no standardized treatment regimen, and affected patients are managed by surgery with or without accompanying radiotherapy and chemotherapy. The overall prognosis is usually poor.