A 20-year-old patient presents

to his general practitioner for a rash. The rash is present mainly on the elbow

and popliteal fossae, and is also present slightly in the scalp (hairy part of

the head). The flat red papules are covered with silvery shiny. When scratched

more vigorously, tiny dots of bleeding occur. Even with a positive family

history, the patient and the physician are almost certain that this is the

first manifestation of psoriasis in this patient. Psoriasis is a non-infectious

inflammatory autoimmune skin disease. The most common manifestation is peeling

of the skin, as it is renewed up to seven times faster than normal, and the

formation and maturation of keratinocytes are abnormally accelerated. The

epidermis is thickened and the stratum granulosum is completely absent. The

stratum granulosum is very typical and easily recognisable because of its

distinctly basophilic hematoxylin-eosin staining. What do these granules contain?