Katsutake Hayasaki

Primary Squamous Cell Carcinoma of the Parotid Gland: A Case Report with Electron Microscopic Findings

Primary squamous cell carcinoma of the parotid gland is a rare tumor. Histological and ultrastructural features of a primary squamous cell carcinoma arising in the right parotid gland is presented. Light microscopically the tumor consisted of poorly differentiated squamous cell nests. PAS reaction was negative. Ultrastructurally the tumor cells were oval or spindle shaped and the cytoplasmic processes were frequently found. The majority of the tumor cells contained numerous intermediate filaments in their cytoplasm. No secretory granule was found. The desmosomes were well developed. It is known that mucoepidermoid carcinoma may be often misdiagnosed as squamous cell carcinoma. These findings can enable us to distinguish primary squamous cell carcinoma from mucoepidermoid carcinoma of the parotid gland.

A proposal of TNM classification system for cancer of the salivary gland--comprehensive retrospective study.

Until recently, there has not been a sufficient number of cases of salivary gland cancer to permit the development of a clinically useful TNM classification system. A comprehensive retrospective study of 354 patients with cancer of the parotid gland from 46 institutions in Japan was carried out at the request of the Japanese Committee on TNM Classification (JJC), and we propose JJC T-categories for parotid gland cancer. The characteristic of this proposal involves T-categories determined according to tumor size. Fixed tumors or tumors with facial nerve involvement were classified as T4 regardless of tumor size. In 1983, the AJC proposal for a TNM classification system of salivary gland cancers was tentatively approved at a AJC/UICC joint meeting. In comparison with the AJC classification, our proposal seems to be better in terms of simplicity and the balanced distribution in T-categories of parotid gland cancers.

Cytologic diagnosis of salivary gland tumors by fine needle aspiration biopsy.

The reliability of cytologic diagnosis of salivary gland tumors by ultrasonically guided fine needle aspiration biopsy was examined preoperatively in 61 cases of parotid gland tumors. To intensify the image of the needle on the electronic linear scan, thin transverse or longitudinal grooves were made at the tip of the needle. Biopsy ecimens were taken by an aspiration pistol with a 21-gauge intravenous needles and 20ml disporsable syringe. The specimens were stained with Papanicolaou, May-Grunwald-Giemsa and occasionally with hematoxylin-eosin. In some cases, electron microscopic studies were performed. In 42 cases of benign tumors there were two false positive diagnoses. In 13 cases of malignant tumors there was one false negative. In six cases of tumor-like lesions there were three poor materials. With regard to the risk to the patient from aspiration biopsy no complication was seen in this series. It is concluded that ultrasonically guided fine needle aspiration biopsyis a safe and reliable technique.