Sequence 1 of 7.

 Acanthosis Nigricans due to rectal carcinoma

 A very extensive Acanthosis Nigricans, with
 adenocarcinoma of the rectum.

 A 73-year-old woman, that noticed a darkness of her face
 during a period of one year and a half. .
  Rectal bleeding started 3 months previously.
 At the time of physical examination, we found this
 striking picture. Digital examination was performed, a hard
 mass was found at the rectum.
 A peptide growth factor from a tumor is related.
 Remission of the skin lesions occurs with removal of the
 tumor.

Sequence 2 of 7.

     Rectum carcinoma and acanthosis nigricans.

 The patient was referred to us because of rectal blood
 discharge.

Sequence 3 of 7.

 Suspicion for malignancy-associated acantosis nigricans
 should arise when it occurs when resent onset in a
 non-obese patient who does not have diabetes.

Sequence 4 of 7.

 There is no satisfactory dermatological or
 cosmetic treatment for acanthosis nigricans, and biopsy of
 the skin is neither helpful.
 The pigmented areas are reversible only when the tumor is
 removed.

Sequence 5 of 7.

    
 Suspicion for malignancy-associated acantosis nigricans
 should arise when it occurs when resent onset in a
 non-obese patient who does not have diabetes.

Sequence 6 of 7.

 Lateral view of her body.
 Hyperpigmentation of some areas are seen.

Sequence 7 of 7.

            A close up of her buttocks. 

 The hyperpigmented areas and queratosis of the skin
 are appreciated.