What Is Responsible for Her Asymptomatic Bump?

A 16-year-old female is brought in by her mother due to concerns about an asymptomatic bump on her ankle that has been persistent for at least 3 months. There is no history of trauma. She is otherwise healthy.

What is responsible for her asymptomatic bump?

A.    Melanocytic nevus
B.    Dysplastic nevus
C.    Melanoma
D.    Granuloma annulare
E.    Dermatofibroma

Answer on next page.

Answer: Granuloma annulare

The characteristic appearance of dull erythematous annular lesion with central depression on a young female is consistent with granuloma annulare. While a biopsy will confirm the diagnosis, it is generally not necessary. 

Note: While a dermatofibroma will dimple downward on lateral compression, it should not have this clinical appearance. Typically these lesions will resolve in several months without treatment. No treatment has been shown to consistently hasten its demise.