Desmoplastic Small Round Cell Tumor of the Submandibular Gland: A Case Report and Literature Review

Abstract

\n BackgroundDesmoplastic small round cell tumor (DSRCT) was a rare and aggressive malignant tumor mostly occurring in the abdominal and pelvic cavity of young patients. However, few cases had been reported concerning DSRCT located in the head and neck region. Case presentationA 25-year-old man was referred to our hospital due to the enlargement of the right submandibular mass. Magnetic resonance imaging revealed a 3 cm×2 cm solid nodule located in the right submandibular, and physical examination showed no other occupying lesion elsewhere. Histologically, the tumor was composed of various-sized small round cell nests, embedded in an abundant desmoplastic stroma. Immunohistochemically, the tumor cells were typically positive for epithelial (CK and EMA), mesenchymal (Vimentin and Desmin), and neuroendocrine marker (CD56, NSE, Syn and CgA), but negative for WT-1. Fluorescence in situ hybridization (FISH) revealed the presence of a break-apart involving Ewing sarcoma region 1 (EWSR1) gene. This tumor was finally diagnosed as DSRCT in the right submandibular gland. The patient received chemotherapy and radiotherapy, and showed recurrence after 17 months of follow-up.ConclusionsDSRCT of the submandibular gland is rare, the diagnosis of this tumor in uncommon location relies on the histomorphology, immunophenotype and EWSR1 gene detection. Differential diagnosis including primary salivary gland tumors and the other small round cell tumors needs to be excluded.