Invasive mucinous adenocarcinoma of the lung revealed by a subcutaneous metastasis: A case report of a rare presentation

INTRODUCTION: Lung cancer stands as the second most prevalent tumour and the foremost cause of cancer-related mortality. It typically manifests through respiratory symptoms. Subcutaneous metastases originating from pulmonary cancers are rare occurrences, with a remarkably low incidence. PRESENTATION OF CASE: A 53-year-old patient, with a history of smoking and unchecked chronic obstructive pulmonary disease, sought care at our outpatient clinic due to the rapid development of a subcutaneous mass. The patient underwent surgical excision of the mass under local anaesthesia. The anatomopathological examination confirmed the diagnosis of cutaneous metastasis from an infiltrative adenocarcinoma. A whole-body CT scan revealed an invasive mucinous adenocarcinoma of the lung. Consequently, palliative chemotherapy was initiated. Unfortunately, the patient succumbed to the disease three months later. DISCUSSION: Subcutaneous metastasis originating from pulmonary sources is a rare phenomenon, with scant literature available on the subject. The presence of pulmonary cutaneous metastasis serves as an ominous sign of rapidly progressing and aggressive lung cancer. The prognosis in such cases is reserved, with an overall survival rate measured in months. The approach to management in these instances predominantly revolves around palliative chemotherapy, although surgical excision of metastases may be considered in select cases. CONCLUSION: Lung cancer unmasked by subcutaneous metastasis represents a rare clinical scenario. While chemotherapy remains the cornerstone of treatment, surgical intervention to remove metastases may be contemplated in a restricted subset of cases. Further research is imperative to ascertain the impact of surgery on both quality of life and overall survival.