Adult colloid milium is clinically distinguishable from its histopathologic mimic cutaneous amyloidosis.

Colloid milium, also known as colloid degeneration of the skin or dermal hyalinosis, is a cutaneous deposition disease that presents as three subtypes: juvenile, nodular, and adult. Adult colloid milium is characterized by amyloid-like depositions in the dermis, mimicking cutaneous amyloidosis histologically. A 70-year-old man presented with lesions on the sun-exposed skin of the face, dorsal hands, and dorsal forearms resembling adult colloid milium. A punch biopsy was performed on the left zygoma and histopathological features were consistent with this diagnosis, though cutaneous amyloidosis was considered. A case of adult colloid milium is presented to emphasize the clinical and histopathologic differentiation from cutaneous amyloidosis.