Acanthosis Nigricans

The image displays a characteristic dermatological finding in the axilla. Which of the following conditions is most likely represented?

A 52-year-old man of Indian origin presents with dark, velvety thickening of the skin in the neck and axillae. On examination, he has skin tags and mild hirsutism. Fasting blood glucose is 180 mg/dL and HbA1c is 9.2%. What is the most common cause of acanthosis nigricans in this patient?

Acanthosis nigricans is most commonly associated with which malignancy in Indian populations?

Which pathophysiologic mechanism is primarily responsible for the skin manifestations in acanthosis nigricans?

A 52-year-old Indian man presents with progressive darkening and thickening of skin over his neck, axillae, and groin for the past 8 months. He reports associated weight loss of 6 kg over 3 months and mild pruritus. On examination, the affected areas show velvety, hyperpigmented plaques with exaggerated skin markings. His fasting blood glucose is 186 mg/dL, and HbA1c is 9.2%. Abdominal examination reveals a palpable epigastric mass. What is the most likely underlying diagnosis?