[Clinicopathological study on multiple primary malignant neoplasms, related to the oral-maxillofacial region].

The present study consists of a clinical and histopathological analysis of those cases which were diagnosed as multiple primary malignant neoplasms of the oral-maxillofacial region and the other organs. 9 patients of those multiple primary malignant neoplasms out of 261 patients of malignant neoplasms in the oral-maxillofacial region, who visited in out department from 1975 to 1986, were detected. 3.4% of the incidence rate was calculated. All the cases were male, and these included each 1 case of triple and quadruple. 7 cases were detected prior in the oral-maxillofacial region to the other organs. There seemed to be a preponderance to early detection of a neoplasm in the oral-maxillofacial region. Therefore, the possibility of multiple primary malignant neoplasms should be kept in mind in the routine clinical activities. 2 cases were synchronous, 6 months or less interval between the first and the second neoplasms, the others were metachronous, averaged 5-year interval. The primary sites in the oral-maxillofacial region were tongue (3 cases), floor of the mouth (2), buccal mucosa (2), lower gingiva (1), maxillary sinus (1), all of them were diagnosed as squamous cell carcinomas, histopathologically. The other organs were esophagus (3 cases), stomach (2), colon (2), lung (2), liver (1), urinary bladder (1), hypopharynx (1). Histopathological diagnoses of them were squamous cell carcinomas (3 cases of esophagus, each 1 case of lung, urinary bladder, and hypopharynx), adenocarcinomas (2 cases of stomach and colon, and 1 case of lung), and a hepatoma. It's necessary to differentiate the multiple primary malignant neoplasms from metastases when each of them were diagnosed as squamous cell carcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)