Malignant acanthosis nigricans associated with ileocecal adenocarcinoma.

Malignant acanthosis nigricans (MAN) is a cutaneous sign of internal malignancy, usually an adenocarcinoma. With this report, we aim to present a rare case of concomitant colon cancer and acanthosis nigricans (AN). A 62-year-old woman with hyperpigmentation, velvety cutaneous thickening and verrucous excrescences involving the axillary, inframammar, and inguinal regions with a history of 10 years is presented. Hyperpigmentation and thickening existed also on the nape, umbilicus, and periorbital regions. Histopathological findings of skin lesions were consistent with AN. Computed tomography of the abdomen revealed cecal wall thickening and multiple enlarged lymph nodes in pericolic fat tissue. The tumor was resected surgically and the diagnosis of poor differentiated adenocarcinoma of the colon with lymphatic metastasis was established. Although MAN is mostly reported in the course of abdominal malignancies, this is a very rare case report of MAN associated with adenocarcinoma of the colon.