[Small round cell desmoplastic tumour. Atypical morphology in the sub-maxillary gland].

Desmoplastic small round cell tumour (DSRCT) is a rare disease usually affecting young males. There are no other articles with a sub-maxillary location. The tumour consists of nests and masses of undifferentiated small round cells embedded in a desmoplastic stroma. The co-expression of epithelial, muscular and neuronal antigens distinguishes this entity from other small round cell tumours. The t(11;22)(p13;q12) translocation is a recurrent characteristic of this type of tumour. We report a case of desmoplastic small round cell tumour of the sub-maxillary gland, with an evolution of 8 months, affecting a 36 year old male. He suffered chronic lymphatic leukaemia five years ago and needed a bone marrow transplant. There was a 4x3 cm tumour. There were no signs of malignancy on the CT scan. A right sub-maxillectomy was performed. The pathology analysis gave a diagnosis of DSRCT. Post-surgical radiotherapy was given. The definitive diagnosis was reached using immunohistochemical techniques, such as polyphenotypical differentiation (epithelial, mesenchymal and neural), and by demonstration of translocation (11;22)(p13;q12). Sub-maxillary location is very rare.