Abstract Background Histiocytic sarcoma (HS) is a rare neoplasm showing morphological and immunophenotypic features of mature tissue histiocytes. We report a patient with nodal HS exhibiting prominent reactive eosinophilic infiltration. Case presentation A 68-year-old man presented with intermittent left lower abdominal pain and weight loss over 3 months. https://myjapanesehomers.shop/product-category/collections/