Metastasis of lung adenocarcinoma to the mandible: Report of a case
A 55-year-old white man, presented with an 8 week history of pain and non-fluctuant swelling at right submandibular area []. He had his right molar tooth extracted and a partial denture was made 10 years ago. One month before our examination, he had a swelling on the affected site and he was prescribed 300 mg clindamycin phosphate IM antibiotics for 5 days by his general dentist. Previous to this, he had paresthesia in the right lower lip for 3 days. Otherwise, the patient had no important medical history. He did not take any systemic medications regularly.\nExtraoral physical examination revealed a right mandibular swelling involving the ramus and the body. Vital signs were normal with hydrated skin and no neck adenopathy present.\nThe intraoral physical examination revealed anesthesia over the peripheral distribution of the inferior alveolar nerve on the affected side with decayed lower and upper canines. The intraoral mucosa was intact and a smooth surfaced non-tender lesion measuring about 2 × 2 cm was noted in the right mandibular premolar-molar area. The orthopantomography showed an ill-defined radiolucent osteolytic lesion of the right molar region under the inferior alveolar canal [].\nThe lesion has an irregular radiolucent area mimicking a dentoalveolar infection located in the corpus of the mandible just below the mandibular canal in the radiographical evaluation.\nThe incisional biopsy under local anesthesia was performed and a histopathological diagnosis of low differentiated adenocarcinoma of the mandibule was given. It was stated in histopathological report that there was a malignant tumoral tissue consisting of solid islands composed of atypical epithelial cells in desmoplastic stroma []. Nuclear pleomorphism in the tumoral islands was marked and cytoplasmic small vacuoles were seen []. This tumoral configuration is compatible with poorly differentiated adenocarcinoma. However, this morphology is not common in oral cavity tumors, including salivary gland tumors. For this reason, it was thought that the tumor was primarily metastatic. This high-degree adenocarcinoma was thought to be originated from the lung, gastrointestinal system, or breast. However, breast was excluded because the patient was male. Classical colorectal carcinoma morphology[] was not seen in this tumor but glandular morphology of gastric adenocarcinoma was more evident. The focus of this tumor was thought to be primarily lung according to the solid island configuration and focal cytoplasmic vacuolization.\nAfter obtaining the report of the biopsy, the patient had consulted the medical oncology department whereour histopathological diagnosis of lung cancer was approved. There was a mass on the left upper lobe of the lung in posteroanterior chest radiogram []. Enlarged aorticopulmonary, subcarinal, left hilar lymph nodes and a mass on superior segment of the left upper lobe of lung on a thorax computed tomography was noted []. However, the patient refused treatment of lung cancer for 1 year. On September 8, 2006, the patient appealed to medical oncology department because his condition became worse. Etoposide 50 mg/day for 21 days, ondansetron 8 mg 3 × 1 IV/po, or granisetron 3 mg 2 × 1 IV/po, or tropisetron 5 mg 1 × 1 IV/po as chemotherapy was initiated but unfortunately, the patient died 5 months after the start of the chemotherapy.