A 55-year-old man presents with velvety, hyperpigmented, thickened skin in the axillae and posterior neck. He has not seen a doctor in years. On screening, a gastroscopy reveals an advanced gastric adenocarcinoma. This cutaneous sign is:

• A Malignant acanthosis nigricans ✓
• B Confluent and reticulated papillomatosis
• C Tripe palms (palmar hyperkeratosis)
• D Leser-Trélat sign

Explanation

Acanthosis nigricans (AN) in the setting of internal malignancy — particularly gastrointestinal adenocarcinoma (most often gastric) — is classified as 'malignant AN'. It tends to be more extensive, rapidly progressive, and may involve atypical sites (lips, palms). It results from aberrant stimulation of keratinocyte growth factor receptors by tumour-derived factors (TGF-alpha, IGF-1). Leser-Trélat sign refers to sudden eruption of multiple seborrhoeic keratoses with internal malignancy. Tripe palms (velvety palmar thickening) often coexists with malignant AN.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.