This 70-year-old man had scattered yellow-to-flesh-colored papules on his sun-exposed skin. The clinician submitted it as actinic reticuloid. Colloid milium (adult form) often occurs on the face and upper extremities of elderly white men, as in this case. The colloid material is thought to be degenerated elastic fibers, and stains with immunohistochemical markers for amyloid P. It is benign. The histology in this case is typical. The differential diagnosis would include other forms of amyloidosis.
Histologic sections of skin show a small nodular deposit within the dermis. There is associated papillary edema. An eccrine unit passes through undisturbed. The epidermis is unremarkable.