[Acanthosis nigricans as the initial paraneoplastic manifestation of gastric adenocarcinoma].

We report the case of a 29-year-old man with cutaneous hyperpigmentation located especially in intertriginous areas. The lesions were velvety, rugose and highly pruriginous. The patient was diagnosed with acanthosis nigricans. Initial treatment with topical corticosteroids and oral antihistamines was unsuccessful and, due to suspicion of a paraneoplastic cutaneous syndrome, gastroscopy with sampling for biopsy and abdominal CT were carried out, revealing the existence of an infiltrating gastric adenocarcinoma and underlying adenopathies. The patient underwent total gastrectomy extended to spleen and pancreatic tail and D2 lymph node dissection. Treatment was completed by radiotherapy and chemotherapy to treat lymph node involvement.