A case of squamous cell carcinoma of submandibular region: it was difficult to determine against primary site

A case of squamous ccll carcinoma of submandibular region, where it was difficult to determine against primary site, was reported. The patient, a seventy-year old male, had hen's egg-sized swelling of submandibular region and white lesion in the left part of floor of the mouth. But the findings from the remainder of the head and neck examination were within normal limits. A biopsy from submandibular lesion demonstrated squamous cell carcinoma. After preoperative chemotherapy and extra irradiation of the submandibular tumor, total neck dissection, excision of floor of the mouth, and segmental resection of mandible were performed in en block. No local recurrence occurred, but two years and seven months after surgery, he died of contralatcral cervical lymph node metastasis. By this time, no evidence of the primary tumor could obtained. The clinical course and close histological examination suggested lymph node metastasized cancer, the primary lesion of which was early carcinoma in the white lesion of the floor of the mouth.