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?

After giving birth, a

32-year-old woman notices that her newborn son has tiny hairs on his back. As

she has never seen anything like this on other children before, she asks the

doctor what it is. The doctor explains that these are the tiny hairs that a

fetus has on most of its body before birth and that they usually disappear before

birth. Sometimes they can remain after birth, but they disappear within days or

weeks at most. What do we call these tiny, fine, light-coloured hairs?

Already when the now 9-month-old boy was born,

he had lighter skin and hair than his parents. Now it is noticeable that his

skin is very light overall, he has blue eyes and blonde hair. The boy has

partial albinism. Albinism is a rare, inherited metabolic disorder caused by a

defect in the enzyme tyrosinase. The disorder results in partial or complete

absence of melanin. Melanin is a pigment synthesized in the melanosomes

(derived from the Golgi apparatus) of melanocytes (cells of the epidermis) from

the amino acid tyrosine. What is the embryonic origin of melanocytes?

A 22-year-old woman comes to the physician because of

a 2-week history of blue staining of her clothes when she exercises.

She noticed that the stains are most prominent on her underwear and under her

arms. She works as a professional ballet dancer and trains at least 40

hours per week. Physical examination

shows black-blue discoloration of the skin in the axillae, areolae,

and perineum. The remainder of the examination shows no abnormalities. Based on

the location, which type of gland is likely to cause this discoloration?

A 36-year-old patient presents for painful

swelling on the skull. The swelling seems like a result of some trauma of which

the patient is unaware. At the same time, the swelling has been present for a

long time. An X-ray of the skull is taken and an osteolytic lesion of the skull

bones is discovered under the swelling (such lesion looks like a hole in the

bones and weakens the strength of the bones). This is a so-called eosinophilic

granuloma. Eosinophilic granuloma is a form of Langerhans cell histiocytosis in

adults. It is a monoclonal proliferation of Langerhans cells – special

dendritic cells of the epidermis. Normal Langerhans cells do not divide

further, whereas cell proliferation occurs in Langerhans cell histiocytosis.

Moreover, these cells further migrate to other organs in this disease. Where these cells are normally found in the skin?

A 66-year-old woman comes to the

physician because of pruritic blister formation. Physical examination

shows multiple 1–3 cm bullae on the palms, soles, lower legs,

and inguinal folds. Gentle rubbing of the skin (epidermis) results in

sloughing of the epidermis. Immunofluorescence studies of a perilesional skin

biopsy show the deposition of antibodies. In which of the following areas are

most likely the depositions of antibodies?

A 68-year-old patient presents to a

dermatologist. He is bothered by a small, light-coloured growth near his left

eye. The dermatologist is rightly concerned that it is a basal cell carcinoma,

which is confirmed by the pathologist after the tumour is removed. Basal cell

carcinoma is a skin tumour arising from keratinocytes of the stratum basale.

This tumor combines some features of both malignant and benign tumours. Which

statement about normal cells of stratum basale is true?

A 78-year-old woman

with type 2 diabetes mellitus comes to the physician for her annual

foot examination. Neurologic examination shows absent sensation to the

vibration of a standardized tuning

fork bilaterally. Sensation

to vibration is normal over the upper extremities. Which of the

following types of sensory receptors is most likely activated in the skin by

this examination?

Students examine each

other from blind slides. Based on this description, what slide could it be?

There is a thin type of skin on the surface. Tiny hair follicles, eccrine

glands, and small holocrine glands are present. A specialty is the presence of

large holocrine glands, which are not connected to any follicles and are

surrounded by a plate of dense connective tissue.

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?