A case of acanthosis nigricans identified by multiple oral papillomas with gastric adenocarcinoma

The patient was a 60-year-old woman. She was referred to the Department of Dentistry and Oral Surgery, for multiple papillomatous proliferations on the oral mucosa. Tumor-like proliferation was found approximately 10 years ago, but she did not have it removed. Papillomatous proliferation appeared on her tongue, upper and lower lips, left and right buccal mucosa, gingiva of the anterior maxilla and pre-molar-mandibula, and gingiva of the hard palate, and she felt her mouth to be dry. Her family history was unremarkable. Her personal history included hypertension. Biopsy revealed papillomatosis and negativity for HPV-16. The dorsa of her hand and nape showed diffuse pigmentation; thus we suspected systemic disease and referred her to the Department of Surgery and the Department of Dermatology. Further investigation suggested stageIV gastric adenocarcinoma with lymphogenous metastasis and multiple papilloma of the esophagus. We also investigated for her symptom of dry mouth and detected Sjögren's syndrome. Thus, we diagnosed neoplastic association type acanthosis nigricans with gastric adenocarcinoma coexisted Sjögren's syndrome. Chemotherapy for gastric adenocarcinoma has initiated. The papillomas on her upper and lower lips were pigmented; therefore we operated several times for functional and esthetic reasons. However, the papillomatous growth did not stop. During chemotherapy, the pigmentation on the dorsa of her hand and nape did not improve, but the papillomatous growth improved.