The American Society of Dermatopathology

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Interactive Case Study - April 2013

Solitary nodular lesion on left leg

Shelby Y. Kunishima, MD; Ashley R. Mason, MD; Jennifer M. McNiff, MD

Question 1:

Clinical History: A 19-year-old male presented with a solitary nodular lesion on the left leg for the past six months, which was positive for S-100 and epithelial membrane antigen on immunohistochemistry.  The histology is shown in Figures 1-4.

Figure 1

Figure 2

Figure 3

Figure 4

What is the best diagnosis?