Interdigitating dendritic cell sarcoma presenting in the skin: diagnosis and the role of surgical resection, chemotherapy and radiotherapy in management.

We report the case of an interdigitating dendritic cell sarcoma (IDCS) presenting in the skin. A 41-year old woman had a slowly enlarging mass on her right scapula that was excised multiple times under a presumptive diagnosis of a recurrent sebaceous cyst. However, the lesion was refractory to standard therapies. History and physical exam was unrevealing for any systemic signs or symptoms of disease. The patient's metastatic work-up was negative. The lesion was resected with wide margins and was found to be consistent with IDCS. Patients that present with IDCS on the skin may present concurrently with metastatic disease and may have increased risk of secondary malignancies. The use of adjuvant chemoradiation after primary resection is controversial. However, the use of chemoradiation likely has benefit for local regional control for primary tumors that are unamendable to complete primary resection.