Oral metastasis of pleomorphic sarcomatoid carcinoma of the lung

OBJECTIVES The aim of the present article is to present and discuss a case of a pulmonary pleomorphic carcinoma with multiple metastases, including a localization in the oral cavity. MATERIALS AND METHODS A 68-year-old woman was admitted to the Emergency Department of Sant'Andrea Hospital at Vercelli, Italy, due to hematemesis. The patient reported a recent slow and progressive weight loss. Furthermore, the patient complained of a swelling in correspondence of the right mandibular molar and premolar edentulous region since several months. The laboratory data revealed anemization. Clinical examination revealed a painless 3 cm mass in the right mandibular crestal region. Therefore, an oral biopsy and an esophago-gastro-duodenoscopy were decided, in agreement with the patient. The esophago-gastro-duodenoscopy revealed two neoplastic lardaceous lesions in the duodenal portion with signs of recent bleeding, that occupied half of the duodenal lumen. A duodenal biopsy was performed and histopathological examination revealed the presence of atypical spindle cells with irregular and hyperchromatic nuclei invasively proliferating and arranged in interlacing patterns. The results of the histopathological examination of the duodenal biopsy and of the oral biopsy together with other examinations, such as total body CT, allowed the diagnosis of sarcomatoid carcinoma (PSC) with pleomorphic features. RESULTS AND DISCUSSION Pulmonary sarcomatoid carcinoma (PSC) is a heterogeneous rare category of primary lung cancer. Pulmonary carcinomas showing a sarcomatoid or sarcomatous cell component are the result of a divergent tumor cell dedifferentiation from epithelial to mesenchymal phenotype in conventional non-smallcell lung cancer (NSCLC). Overall, sarcomatoid carcinomas are poorly differentiated NSCLCs (squamous cell carcinoma, large-cell carcinoma and/or adenocarcinoma) containing a component of sarcoma-like or true sarcomatous elements. In particular, pleomorphic carcinoma is the most common type of PSC, followed by spindle cell carcinoma, giant cell carcinoma, carcino-sarcoma, and pulmonary blastoma. CONCLUSIONS The additional sarcomatoid/sarcomatous component in an otherwise conventional NSCLC is due to up-regulation of the epithelial-to-mesenchymal transition (EMT) following the activation of genetic mechanisms associated with resistance to chemotherapy and tyrosine kinase inhibitors, such as KRAS mutations, c-MET gene alterations, overexpression of vimentin, ZEB1, Snail, MiR-34 coupled to downregulation of E-cadherin and expression of epithelial markers, miR-200, mutations of EGFR. CLINICAL SIGNIFICANCE Dental practitioners should be aware of the clinical manifestations and the aggressive behaviour of pleomorphic carcinoma, to allow an early diagnosis and an appropriate treatment.