Squamous cell carcinoma of the tongue with cardiac metastasis on 18F-FDG PET/CT A case report and literature review

Introduction: The most common malignancies metastasizing to the heart are cancers of the lung, breast, mesothelioma, melanoma, leukemia, and lymphoma. Cardiac metastasis from a tongue cancer is a rare finding and only a few cases have been reported previously in the literature. In this case report and literature review, we discuss the main clinical features of patients with cardiac metastases secondary to a tongue cancer and imaging modalities performed, especially the F-18-Fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT). Patient concerns: This is a case of a 39-year-old woman who in April 2018 was diagnosed with an invasive well differentiated squamous cell carcinoma of the movable tongue. She underwent a left hemiglossectomy followed by a revision of hemiglossectomy and ipsilateral selective neck lymph nodes dissection levels II to III because of pathological margins. An early inoperable clinical recurrence was diagnosed and she received radiochemotherapy with good clinical and metabolic response. She remained asymptomatic thereafter. Diagnosis: In January 2020, a pre-scheduled F-18-FDG PET/CT showed a diffuse cardiac involvement. In February 2020, a biopsy of the lesion revealed a metastatic squamous cell carcinoma. Interventions: She was deemed to not be a cardiac surgical candidate and treated by palliative chemotherapy: taxol-carboplatin associated with cetuximab then cetuximab alone because of adverse effects. A re-evaluation imaging performed in April 2020 evidenced a progression of the cardiac involvement, which led to switch chemotherapy by immunotherapy with nivolumab. Outcomes: This patient had a very poor prognosis and succumbed to major heart failure 4 months after the diagnosis of cardiac metastasis. Conclusion: In this case report, F-18-FDG PET/CT proved to be useful in detecting cardiac metastasis and changed the therapeutic management of the patient. It suggests that patients with tongue malignancies in a context of poor initial prognosis should be followed-up early by F-18-FDG PET/CT with HFLC diet to facilitate detection of recurrence.