RESUMEN
Lateral cervical cysts containing squamous cell carcinoma is a diagnostic and therapeutic challenge for the clinician since they usually represent a cystic metastasis from an occult carcinoma. Various imaging modalities or even blind biopsies will help identify the primary tumour. If the primary tumour is identified, an appropriate treatment decision can be made that incorporates both the primary tumour and the cervical node. If the primary remains unidentified, the neck is treated with a modified or radical neck dissection, depending on the extent of metastatic disease, and radiation therapy is administered to Waldeyer's ring and both necks. We present in this paper, a case with a large cervical cyst where histology showed the presence of a poorly differentiated squamous cell carcinoma in the wall of the cyst. A diagnostic evaluation of the patient was negative. Blind biopsies of the right tonsil revealed occult squamous cell carcinoma. The patient was treated by combined chemo/radiotherapy and she is doing well nine months following excision of the mass. The relevant literature is briefly reviewed.