Malignant acanthosis nigricans: an early diagnostic clue.

Acanthosis nigricans (AN) is characterized by velvety, hyperpigmented, verrucous, symmetric and occasionally pruritic plaques along with papillomatous lesions which have a special predilection for neck, axillae, groin, umbilicu and mucosal regions. Rarely, it presents as a paraneoplastic syndrome and prompts a thorough search for an internal malignancy. We present here a case of malignant acanthosis nigricans seen in an elderly patient who was found to have underlying adenocarcinoma of the lower end of esophagus. After diagnosing associated malignancy, he was referred for further evaluation and subsequent surgical resection of tumour.