Primary Head and Neck Histiocytic Sarcoma of the Oropharyngeal Posterolateral Wall: A Case Report.

Histiocytic sarcoma (HS) is a rare and aggressive malignancy, particularly uncommon in the head and neck region. This report describes the case of a 67-year-old male with HS originating from the oropharyngeal posterolateral wall, treated successfully with transoral CO2 laser excision and adjuvant proton radiotherapy. Despite achieving 20 months of disease-free survival, the patient developed severe radionecrosis, underscoring the need to balance oncological control with treatment-related morbidity. This case highlights the importance of multidisciplinary approaches, comprehensive histopathology, and tailored therapeutic strategies for managing such rare malignancies.