Cylindroma

Figure 5.4
A: Eccrine poroma, scalp*
B: Eccrine poroma, plantar
(Courtesy of Dr. Sophie M.
Worobec)
C: Cylindroma*
*Courtesy of Dr. Paul Getz

(Figure 5.4C)

Presents as single or multiple firm, rubbery nodules with erythematous to blue color, often on scalp
Histology: well-demarcated basaloid proliferation in dermis consisting of discrete lobules of cells arranged in “jigsaw” or mosaic pattern, hyalinized cylinders seen surrounding lobules, and hyalinized droplets often admixed with tumor cells
Multiple cylindromas seen with CYLD mutation either in cylindromatosis or in conjunction with other skin appendage tumors in Brooke–Spiegler syndrome