Diagnosis of an occult gastric adenocarcinoma by oral manifestations (acanthosis nigricans): A case report.

Background: Acanthosis nigricans (AN) is a condition with an important characteristics of symmetrical areas of thickened skin with grayish brown hyperpigmentation. The mucosa may show a papillomatous surface, with or without hyperpigmentation. Lips and sites at risk of trauma may be affected and palmoplantar keratosis might also be present. In some rare cases, acanthosis nigricans presents as a sign of internal neoplasia, mostly a gastrointestinal cancer, and is called malignant acanthosis nigricans (MAN).

Case Presentation: In this study, a 55-year-old female Iranian patient with malignant acanthosis nigricans (MAN) is reported. She was seeking esthetic treatment for her oral and perioral regions. The peculiarity of this case is simultaneous skin manifestation consistent with MAN, "tripe palms" (TP) and Leser-Trélat (LT) sign and mucosal changes in the oral cavity such as papillomatosis and roughened surfaces of the lips, hard palate and buccal mucosa. These changes harbored gastric adenocarcinoma stage T3 N3, but the patient was asymptomatic except for pruritis.

Conclusion: There is an urgent need to suspect a correlation between oral and skin changes and the possibility of an internal neoplasia, therefore it is of utmost importance to refer these patients for early diagnosis of the underlying disease. This would improve the prognosis and lessen the consequences to a great extent.