Primary Cutaneous Histiocytic Sarcoma: A Rare Case.

Area of Science:

• Oncology
• Dermatopathology

Background:

• Histiocytic sarcoma is a rare malignancy with variable presentation, often diagnosed late and associated with poor prognosis.
• Neoplastic cells mimic macrophages, commonly affecting lymph nodes, gastrointestinal tract, CNS, spleen, skin, and soft tissues.

Observation:

• An 80-year-old patient presented with a solitary subcutaneous forearm lesion.
• Histological examination confirmed cutaneous histiocytic sarcoma, with tumor cells positive for CD163 and CD68.

Findings:

• Complete surgical excision followed by adjuvant radiotherapy led to a favorable outcome.
• The patient remained disease-free at one-year follow-up, suggesting localized disease has a better prognosis.

Implications:

• Unifocal cutaneous histiocytic sarcoma may have a more favorable prognosis than disseminated forms.
• While treatment is not standardized, advances in genomic profiling may enable targeted therapies for histiocytic sarcoma.