Surgery>>>>>The Skin and Subcutaneous Tissue
Question 8#

Trichilemmal cysts:

A. Are the most common type of cutaneous cysts
B. Are found between the forehead to nose tip
C. Are typically found on the scalp of females
D. Occasionally develop bone, tooth, or nerve tissue

Correct Answer is C

Comment:

There are three types of cutaneous cysts: epidermal, dermoid, and trichilemmal. All of these benign entities comprise epidermis that grows toward the center of the cyst, resulting in central accumulation of keratin to form a cyst. All clinically appear as a white, creamy substance-containing subcutaneous, thin-walled nodule. Epidermal cysts are the most common cutaneous cyst and histologically characterized by mature epidermis complete with granular layer. Trichilemmal cysts are the second most common lesion; they tend to form on the scalp of females, have a distinct odor after rupture, histologically lack a granular layer, and have an outer layer resembling the root sheath of a hair follicle. Dermoid cysts are congenital, found between the forehead to nose tip, and contain squamous epithelium, eccrine glands, and pilosebaceous units, occasionally developing bone, tooth, or nerve tissue. The eyebrow is the most frequent site of presentation. These cysts are commonly asymptomatic but can become inflamed and infected, thus necessitating incision and drainage. After the acute phase subsides, the entire cyst should be removed to prevent recurrence.