Cutaneous Metastasis of Gastric Adenocarcinoma: A Report of a Rare Case and a Literature Review.

Cutaneous metastases from visceral malignancies occur in a minority of patients. Gastric adenocarcinoma rarely seeds the skin and often masquerades as benign dermatoses, which can delay diagnosis. We report an 80-year-old man with stage IV gastric adenocarcinoma with rapidly enlarging nodules of the lower lip and chin. A pedunculated lesion of the right lower lip involving the vermilion border and a nodule on the left chin had enlarged over five weeks. The lip excision measured 2.6 × 2.1 cm, and the chin excision 1.2 × 2.2 cm. The lip specimen showed cytoplasmic positivity for pan-cytokeratin (AE1/AE3) and a markedly elevated Ki-67 proliferation index. The findings supported metastatic adenocarcinoma consistent with the patient's known gastric primary. This case highlights that rapidly evolving or indurated skin lesions can occur even at atypical sites such as the lip and chin. Thus, an urgent biopsy in patients with known or suspected malignancy can be beneficial. Histologic and immunophenotypic confirmation enables timely staging, realistic prognostic discussions, and symptom-directed interventions. While local excision can provide meaningful palliation, cutaneous dissemination from gastric adenocarcinoma generally reflects widespread disease and limited survival.