Sarcomatoid carcinoma after radiotherapy for early-stage oral squamous cell carcinoma: Case report

Sarcomatoid carcinoma is a rare variant of squamous cell carcinoma (SCC) with poor prognosis. Previous radiation has been reported as one of the etiologic factors.

We describe a case of a 57-year-old man presented with a painless mass in the left supraclavicular area. Five years before, he was diagnosed with SCC in floor of mouth (FOM) and underwent radiotherapy (RT).

Sonography-guided biopsy on the supraclavicular lymph node revealed diffuse spindle cell proliferation with a focus of squamous differentiation. Local recurrence on primary site or distant metastasis was not obvious on both computed tomography (CT) of the neck and F-fluorodeoxyglucose positron emission tomography CT. The final diagnosis was confirmed as sarcomatoid carcinoma via surgery.

The patient underwent surgery including explorative resection of the mouth floor, excision of the submandibular gland, and modified radical neck dissection. Following surgery, the patient received adjuvant radiation therapy.

There were no complications according to the surgery. Six months after adjuvant therapy, distant metastasis to liver was identified. The patient is currently undergoing palliative chemotherapy.

This may be the first reported case of sarcomatoid carcinoma arising from early-stage SCC in FOM that was previously treated with RT alone. When RT is performed as a single modality for oral SCC, even in an early stage, rigorous follow-up should be performed.