A VERY elderly lady with a "knot on her head"...

You are working one evening when a very pleasant 104 yo woman presents with a "knot" on her head.  It is painless, but unsightly, and she would like to know what it is.

What do you tell her?  What do you do next?

Answer:

This patient has a cutaneous horn. Cutaneous horns are  keratinous skin tumors which grow above the surface of the skin.  They are often benign but can be associated with premalignant lesions.   While the cause of these growths is unknown; they appear most often on sun exposed skin.  In the case of squamous cell carcinoma, it is known that actinic keratosis is a premalignant lesion.  It was recently demonstrated that squamous cell ca circumvents the immune system by down regulating E-selection expressed on tumor vessels which prevents T lymphocytes from entering the area. 

While the lesions are most often small; they have been reported up to 9.8 inches.  This particular horn was excised from a woman in France in the 19th century and a wax model of her head  is on display at the Mutter museum in Philadelphia . 

The skin is a physical barrier to the environment and because of this the skin is the largest immune organ.  When it becomes overwhelmed  by damage for example  from UV; light tumors develop.  Immune function decreases with aging.  The three major causes of disease in aging are: an increase in autoimmune disease, failing surveillance allowing cancers to develop and increased susceptibility to infectious disease.  The skin has decreased vascularity with aging and in addition in vivo functions of neutrophils are altered.  There is decreased endothelial adherence, slower migration and decreased supraoxide creation all leading to increased numbers of malignancy in the elderly.

Treatment:  The cutanous horn was removed surgically and found to have a low grade squamous cell carcinoma at the base.  It was resected totally

1.    Solivan GA, Smith KJ, James WD  1990 Cutaneous horn of the penis: Its association with squamous cell carcinoma and HPV-16 infection” Journal of the American Academy of Dermatology 23 (5 Pt 2): 969-72.
2.    Copcu E, Sivrioglu N, Culhaci N. “Cutaneous horns: are these lesions as innocent as they seem to be?” 2004 World Journal of Surgical Oncology 2: 18.
3.    Bulman A, Neagu M, Constantin C. Current Proteomics 2013 . “Immunomics in skin cancer-Improvement in diagnosis, prognosis and therapy monitoring.” 10(3)
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