A 35-year-old female presents with an enlarging, painless “lump” on her left posterior shoulder. She denies weakness or paresthesias of her left upper extremity. Her maternal uncle, mother, brother, and herself have a history of multiple colonic polyps, jaw osteomas and epidermoid cysts. She ultimately undergoes biopsy of the mass. Which of the following is most likely to be consistent with the histology of the biopsy specimen?