Linfoma de células en anillo de sello que simula carcinoma mucosecretante

signet ring cell lymphoma is a rare neoplasm caracterized by large, vacuolated and clear cells mimicking mucin-producing adenocarcinoma. it is localized in nodal and extranodal sites. a case of a 59 years old male, with a diffuse lymphoma signet ring cell type localized on oropharingeal mucosa is reported. the histopathology study showed signet ring cells and the immunophenotype was: vimentine(+), cd45(+), cd20(+), ig m(+), kappa chain(+) and high index proliferative activity of neoplastic cells (ki 67:70%). after a review of the literature and previous reports, we could not find a similar case in this anatomic site. the patient had a unfavourable clinical course and died two months after the diagnosis without receiving any treatment.