Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Telogen Effluvium—An Inflammatory Disease?

“Telogen effluvium signifies the loss of normal club hairs from resting follicles which have performed the ritual of involution, catagen, in the prescribed [sic] fashion. Inflammatory signs or other histologic abnormalities are necessarily m…

Differential Diagnosis in Dermatopathology

Discussions

…pilar sheath acanthoma are constituted mostly of cells of the isthmic part of a hair follicle. The infundibular rete ridges of dilated pore are devoid of ducts or cysts, whereas the lobules of pilar sheath acanthoma usually contain structures like s…

Differential Diagnosis in Dermatopathology

Study By Disease

…ma (Quiz #615) Follicle-center lymphoma (Quiz #390) Follicular cyst, isthmic-catagen type (Quiz #636) Follicular cyst, isthmic-catagen type, ruptured (Quiz #65) Folliculo-apocrine cystic hamartoma (Quiz #74) Foreign body granulomatous dermatitis and…

Histologic Diagnosis of Inflammatory Skin Diseases

Foreign body reaction

…o matter how resolute. Corneocytes from ruptured infundibular cysts rival suture as the cause primary of foreign body granuloma in the skin (and subcutaneous fat). Cornified contents of epidermal (infundibular) cysts and of follicular (isthmic-catag…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

…re arranged in delicate laminate fashion 3. Cornified cells in cystic structures are arranged compactly 4. Rete ridges protrude from infundibular epithelium that lines the cyst 4. Bulbous aggregations of isthmic epithelium are continuous with cysti…

Histologic Diagnosis of Inflammatory Skin Diseases

Telogen effluvium

…from normal scalp, not only because the number of follicles in catagen may be so few, but because, episodically, a single follicle in catagen may be seen in a section from a 4.0 mm specimen taken from a normal scalp; catagen is a phase expected in a…

Differential Diagnosis in Dermatopathology

Common baldness vs. Telogen effluvium

An inflammatory process that develops secondary to trauma, usually in the form of a penetrating injury or rupture of a follicle, and that proceeds through stages of granulation tissue with numerous extravasated erythrocytes, granulomatous inflammati…

Histologic Diagnosis of Inflammatory Skin Diseases

Applicable Terms

…Laminated orthokeratosis is found, too, in a type of epidermal cyst, i.e., an infundibular cyst, and in a “pseudocyst,” i.e., an infundibular tunnel in a lesion of seborrheic keratosis. Infundibular hyperkeratosis is the sine qua non for…