FOLLICULAR TUMORS

Question 1

Identify the pointed structures

Answer 1

Question 2

Answer 2

STEM / SUPRABULBAR AREA

Question 3

Identify the pointed structures

Answer 3

• outer root sheath - clear cells because of abundant glycogen on the cytoplasm

Question 4

Answer 4

Isthmus

Trichilemmal keratinization - without granular layer

Question 5

Answer 5

Infundibulum - lined by epithelium identical to the epidermis; (+) granular layer

Question 6

follicular tumors with infundibulum differentiation

Answer 6

• Trichoadenoma
• Dilated pore of winer
• Folliculo-sebaceous cystic hamartoma (FSCH)

Question 7

Follicular tumors with Outer root sheath/ trichilemmomal differentiation

Answer 7

• Inverted follicular keratosis
• Pilar sheath acanthoma
• Trichilemmoma
• Trichilemmal/ pilar cyst
• Proliferating trichilemmal/ pilar cyst

Question 8

Follicular tumor with hair matrix differentiation

Answer 8

Pilomatricoma

Question 9

Question 10

Answer 10

Question 11

Answer 11

• central crater keratinizes through a granular layer
• smaller bluish projecting epithelial buds

Question 12

Answer 12

• central crater keratinizes through a granular layer
• Bigger buds than that of dilated pore; w/ isthmic character;
• (+/-) duct.

Question 13

Answer 13

• Central cystic structure that opens to the skin; with infundibular differentiation .
• Smaller secondary mature or immature/abortive follicles radiate out into the dermis. (Inferior segment differentiation)
• Interfollicular bridges connect radiating follicular structures
• Surrounding Stroma: fibrotic & “encapsulates” the neoplasm

Question 14

1. diagnosis
2. differentiation

Answer 14

1. DILATED PORE (of WINER)
2. follicular infundibulum

Question 15

Answer 15

PILAR SHEATH ACANTHOMA

Question 16

Answer 16

TRICHOFOLLICULOMA

Question 17

Answer 17

Question 18

Answer 18

• CATEGORY: CYSTS
• Dermal-based cyst
• Lined by stratified squamous epithelium WITHOUT a granular layer
• Central abrupt compact keratinization (trichilemmal differentiation)
• Epithelial lining resembles isthmus follicular outer root sheath

Question 19

Answer 19

Question 20

Answer 20

Question 21

Answer 21

• no koilocytes

*have numerous squamous eddies

Question 22

1. Diagnosis
2. Associated syndrome
3. gene mutation

Answer 22

1. TRICHILEMMOMA
2. Cowden syndrome
3. PTEN

• Multiple trichilemmoma – a major criterion for Cowden’s syndrome.
• a wart-like silhouette; hyperkeratosis, hypergranulosis, even epidermal colarette,
• thickened epithelium w/ bulbous lobular contour
• pale or clear cells;
• peripheral palisading at the outer margin
• thick basement membrane.
• (+/-) squamous eddies and microcysts

*mimics outer root sheath with clear / pale eosinophilic lobules with peripheral pallisading and thick basement membrane

Question 23

Multiple trichilemmoma is seen in what syndrome

Answer 23

Cowden’s Syndrome

Question 24

1. Diagnosis
2. Associated conditions?

Answer 24

Question 25

Answer 25

Question 26

Answer 26

Trichoblastoma

Question 27

Answer 27

Question 28

Answer 28

Question 29

How can you differentiate TRICHOBLASTOMA (TB) / TRICHOEPITHELIOMA (TEP) VS BCC

Answer 29

Question 30

SYNDROMES WITH TRICHOBLASTOMAS/ TRICHOEPITHELIOMAS

Answer 30

* Brooke Fordyce syndrome: multiple trichoblastomas * Brooke Spiegler Syndrome: Spiradenomas, cylindromas, and trichoepitheliomas (cribriform trichoblastomas) * Rombo syndrome: Atrophoderma vermiculata, milia, hypotrichosis, BCC, trichoepitheliomas, peripheral cyanosis * Bazex syndrome: : Atrophoderma vermiculata, hypotrichosis, hypohidrosis, trichoepitheliomas, BCC. * Gardner’s Syndrome: Epidermoid cysts, desmoid tumors, multiple trichoepitheliomas, fibromas, lipomas, leiomyomas, osteomas * Rassmusen’s syndrome: Trichoepitheliomas, milia and cylindromas * Multiple Familial Trichoepithelioma*

Question 31

Answer 31

Question 32

most frequent benign secondary lesion arising from Nevus sebaceus

Answer 32

Syringocystadenoma papilliferum followed by trichoblastoma

Question 33

Most common malignant lesion arising from nevus sebaceus

Answer 33

BCC

Question 34

1. Diagnosis 2. Differentiation 3. MC site

Answer 34

1. Trichofolliculoma 2. Panfollicular 3. Nose

Question 35

1. Diagnosis 2. Associated syndromes 3. MC in what age group 4. associated gene mutation

Answer 35

1. Pilomatricoma 2. Gardner syndrome, myotonic muscular dystrophy, and Rubinstein-Taybi syndrome 3. children and young adults 4. CTNNB1 ## Footnote (B) peripheral nucleated basaloid cells and central eosinophilic shadow cells (ghost cells). C, The basaloid cells have round nuclei resembling pilar matrical cells, whereas shadow cells are composed of eosinophilic cellular material with a faint outline of nuclear membrane.

Question 36

Answer 36

Trichilemmoma

Question 37

Answer 37

**Trichilemmoma** is an endophytic proliferation of epithelial cells with clear cytoplasm resembling the hair follicle outer root sheath; the surface may have a verrucous appearance. ## Footnote B, There is a palisaded proliferation of basaloid cells, surrounded by a variably dense eosinophilic hyaline membrane; the clear cells have round to oval nuclei without cellular atypia.

Question 38

1. diagnosis 2. differentiation

Answer 38

1. Trichoadenoma 2. follicular infundibulum ## Footnote 1st photo: Low-magnification view of a trichoadenoma shows a dome-shaped lesion based in the dermis. Note numerous mature horn cysts image. There is focal granulomatous inflammation surrounding the keratin debris image. 2nd photo: High magnification view of a trichoadenoma highlights the sclerotic stroma and the loose keratin debris within the horn cysts image. There are basaloid buds off of horn cysts image and in the stroma image. >> well-circumscribed, dermal nodule composed of infundibulocystic structures (keratin cysts) within a fibrotic/ sclerotic stroma.