A 34-year-old woman comes to the physician for evaluation of skin lesions. For the past year, she has noticed darkening and thickening of the skin over her neck and groin areas. These areas occasionally feel itchy. Her blood pressure is 130/80 mm Hg. Skin examination findings are shown in the image below. Similar hyperpigmented, velvety lesions are found on the axilla and groin. This patient's condition is most likely associated with which of the following?

Question

A 34-year-old woman comes to the physician for evaluation of skin lesions.  For the past year, she has noticed darkening and thickening of the skin over her neck and groin areas.  These areas occasionally feel itchy.  Her blood pressure is 130/80 mm Hg.  Skin examination findings are shown in the image below.  Similar hyperpigmented, velvety lesions are found on the axilla and groin.  This patient's condition is most likely associated with which of the following?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d36f_5be0_bc81_df8752a766df_MD0003_00 This image shows the typical presentation of acanthosis nigricans (AN), which is characterized by hyperkeratotic, hyperpigmented plaques with a classic "velvety" texture. Flexural areas, particularly the axilla, groin, and posterior neck, are the most common locations affected. Depending on the etiology, AN can be divided into benign and malignant forms: Benign AN is typically seen in younger individuals and is associated with insulin-resistant states (eg, diabetes mellitus, obesity, polycystic ovarian syndrome). Increased levels of insulin and/or insulin-like growth factors are thought to stimulate epidermal and dermal proliferation. Similarly, skin tags (acrochordons), which are pedunculated outgrowths of normal skin, are also commonly present on regions affected by AN. Malignant AN (Choice C) is associated with underlying neoplasms, especially of the gastrointestinal and genitourinary tracts. The sudden appearance of such skin changes in middle-aged or elderly patients is suggestive of underlying malignancy. In addition, these patients are not obese (but instead may have lost weight), and lesions can occur in uncommon areas (eg, mucous membranes, palms, soles). (Choice A) Hyperpigmentation of the skin in primary adrenal insufficiency (Addison's disease) is generalized. However, it is more prominent in areas exposed to friction (eg, elbows, knees) and light (eg, face, dorsum of hands). The other findings of Addison's disease are vitiligo, dehydration, and hypotension. This patient's normal blood pressure and characteristic skin findings are not suggestive of Addison's disease. (Choice B) Diabetes mellitus and hyperpigmentation of the skin are features of hemochromatosis ("bronze diabetes"), but the characteristic skin findings are different from those of acanthosis. The coloration in hemochromatosis is typically brownish or bronze, and at times slate gray. The hyperpigmentation also tends to be more prominent on sun-exposed skin, especially the face. (Choice D) Niacin deficiency (pellagra) typically presents with photosensitive dermatitis, erythematous tongue, diarrhea, vomiting, and neurologic symptoms (eg, insomnia, dementia, confusion). Educational objective: Acanthosis nigricans is characterized by symmetrical, hyperpigmented, velvety plaques in the axilla, groin, and neck. It is associated with insulin resistance states (eg, diabetes mellitus, polycystic ovarian syndrome) in younger patients and gastrointestinal malignancy in older individuals.

A 34-Year-Old Woman Comes to the Physician for Evaluation of Skin