A Case of Complete Abscopal Response in High-Grade Pleiomorphic Sarcoma Treated with Radiotherapy Alone

"Abscopal response" refers to the spontaneous involution of untreated metastatic disease following local primary tumor-directed therapy. We report a case of an abscopal response of untreated lung metastasis in a man with pleomorphic sarcoma of the head and neck treated with hypofractionated radiotherapy.

An inoperable pleomorphic sarcoma of the postauricular soft tissue was treated with 40 Gy of radiation in eight fractions. Untreated disease in the lungs was followed with CT scans.

At the two-month post-treatment follow-up, clinical exam and restaging CT demonstrated complete primary tumor involution. Additionally, CT chest images showed a dramatic disease response in the untreated pulmonary disease, which progressed to complete and persistent clinical response at one-year post-treatment follow-up.

We report the first described case of a complete abscopal resolution of untreated lung metastases in a patient with a primary pleomorphic sarcoma of the head and neck treated with hypofractionated radiotherapy.