What could be causing this tender subcutaneous nodule?

A 45-year-old female presented with a painful nodule on her finger that has been slowly growing over the last several months. There is no history of trauma or foreign body.  

What could be causing this tender subcutaneous nodule?

A. Angiolipoma
B. Neuroma
C. Glomus tumor
D. Eccrine spiradenoma
E. Leiomyoma 
F. All of the above

(Answer and discussion on next page)

Answer: Neuroma

ANGELs (angiolipoma, neuroma, glomus tumor, eccrine spiradenoma, and leiomyoma) are all subcutaneous or dermal benign tumors characterized by pain upon compression. Angiolipomas are usually on the trunk and proximal extremities and appear like a lipoma. Glomus tumors can be seen on the digit, but have a purplish hue similar to the eccrine spiradenoma. Leiomyomas arise from pili erector muscle, which is absent on the fingertip. 

This histologic variant was a neuroma, which is very uncommon but can be removed by excision.