Scrotal Skin Metastasis of Lung Adenocarcinoma: A Rare Case Report

Scrotal skin metastasis is extremely rare, predominantly originating from urogenital or gastrointestinal malignancies. Lung adenocarcinoma metastasis to the scrotum has been reported in only a limited number of cases in the literature. A 71-year-old male with a known diagnosis of lung adenocarcinoma presented with a progressively enlarging, painless 3 × 3 cm nodular mass in the right hemiscrotum. Histopathological and immunohistochemical examination confirmed metastatic pulmonary adenocarcinoma (TTF-1+, CK7+, P40−). The patient declined systemic therapy and experienced rapid disease progression, dying three months after the diagnosis of scrotal metastasis. This case highlights that metastatic disease should be considered in the differential diagnosis of scrotal lesions in patients with known malignancy, and underscores the value of immunohistochemistry in establishing the diagnosis.