Pathological fracture of the mandible resulting from a metastatic osteolytic lesion from a primary pulmonary adenocarcinoma: a case report

Aim: Metastatic tumors to bone must be considered in all patients with unexplained bone pain, but in particular in patients who present with known cancer, localized pain at multiple sites, and ndings suggestive of metastasis. The purpose of this report is to present a case of a pathological fracture of the mandible as a consequence of metastatic pulmonary adenocarcinoma. Methods: In July 2018, a non-smoking 68-year-old male patient, came to our clinic, referred by the geriatric ward, for specialist evaluation. He complained of pain (VAS: 5) in the right temporomandibular region exacerbated, over the past few days, by chewing, and resulting in a reported functional limitation. The patient was hospitalized with a primary diagnosis of pulmonary adenocarcinoma (T2-T3 N2 Stage IIIA) diagnosed in December 2017 and treated with a completed course of radiation therapy and chemotherapy. Intense corticosteroid therapy for the adenocarcinoma led to heart and liver complications as well as vertebral collapse. Physical examination showed monolateral swelling of the right temporomandibular joint (TMJ) in the absence of joint clicks. A slight limitation of motion was observed with mouth opening. Intraorally, diffuse white lesions compatible with pseudomembranous candidiasis were detected. A Panoramic radiograph demonstrated a right intracapsular condylar compound fracture associated with an osteolytic lesion at the condyle base with jagged margins. A CT scan with contrast of the facial solid mass and ne-needle aspiration of the lesion were performed. Results: CT con rmed the presence of a right mandibular condyle fracture associated with a large osteolytic lesion, located at the neck of the condyle. The size was approximately 9 mm antero-posteriorly, 6 mm medial lateral, and 17 mm cranial caudal. The lesion was characterized by irregular margins and cortical involvement both on the medial and lateral sides. The above con rmed the pathological nature of the fracture. Suspicious lymphadenopathy was not observed in the cervical lymph nodes. Fine-needle aspiration of the metastatic lesion con rmed the presence of medium and large size adenocarcinoma cells with a large cytoplasm, sometimes apocrine in appearance with focal secreting aspects, mostly central nuclei with severe anisonucleosis and gross eosinophilic nucleoli. It was not possible to proceed with a mandibular resection due to the critical clinical condition of the patient who died in September 2019. Conclusions: Lung cancer frequently produces lytic- type metastases. In patients with a known diagnosis of pulmonary malignancy, panoramic radiographs are recommended to search for early areas of bone radiolucency in the symptomatic jaw.