A 68 year old male with abdominal pain, anorexia, and facial skin pigmentation.

A 68-year-old, heavy smoker male was admitted with abdominal pain and distention. He had weight loss and constipation since 1 year ago and loss of appetite since 2 months ago. He complained from facial skin darkening since 1 year ago.

Physical examination showed skin thickening, pigmentation in his face, and upper parts of neck [Figure 1] and hepatomegaly.

Figure 1

Skin pigmentation in his face and upper parts of neck

Laboratory findings are included: WBC = 13000/μl, Hb = 15 gr/dl, Plt count = 254000/μl. AST = 48 (normal < 50 U/L), ALT = 20 (normal < 50 U/L), alkaline phosphatase = 1048, high (normal: 80-306 U/L), CEA = 38 (normal < 8 for smokers).

FBS, Na, K, BUN, and Cr all were reported normally. HBs Ag and HCV Ab were negative. Sonograpghy showed hepatomegaly with multiple mass lesions in liver lobes suggestive of liver metastasis. Upper GI endoscopy showed severe erosive gastritis. Liver biopsy showed carcinoma (primary or secondary). Immunohistochemistrical (IHC) study on biopsy was reported positive for keratin, EMA, SMA, and negative for S100, PSA, MA, CD117) that recommended epithelial, myoepithelial origin for cancer.

Question

What is your diagnosis for Figure 1?

Answer

Acanthosis nigricans is a paraneoplastic dermatosis which is characterized by skin thickening and pigmentation with a velvety appearance especially on flexor surfaces and skin folds such as axilla, posterior neck folds and inguinal areas. It is reported rarely in skin of face in literature.[1] It may be idiopathic. Secondary forms may be due to endocrinopathies[2] underlying cancer[13]; some drugs (Nicotinic acid, Stilbesterol, and Corticosteroids)[4] and familial forms.[5]