Ch. 4 - Pilar & sebaceous neoplasms

Question 1

Pilomatricoma (calcifying epithelioma of Malherbe)

Answer 1

Large ball with internal trabeculae. Basophilic cells keratinizing to form shadow cells. Calcification (or bone fomration!) with giant cell granulomas.

Question 2

Pilomatrical carcinoma

Answer 2

Rare atypical and infiltrative lesions that arises in long-standing pilomatricomas.

Question 3

Trichoblastoma

Answer 3

Blue follicular tumors composed of basaloid cells. No retraction artifact. Stroma resembles normal fibrous sheath with contentric collagen and papillary mesenchymal bodies.

Question 4

Trichoepithelioma

Answer 4

A type of trichoblastoma with finger-like projections and cribriform nodules.

Question 5

Name 3 syndromes associated with trichoepitheliomas.

Answer 5

Multiple trichoepitheliomas (AD-inherited)

Brooke-Spiegler syndrome (+cylindromas)

Rombo syndrome (+milia, hypotrichosis)

Question 6

Desmoplastic trichoepithelioma

Answer 6

Firm doughnut-shaped lesion with central dell and Paisley-tie pattern. Red desmoplastic stroma. Affects young women.

Question 7

Name 5 lesions that show “Paisley-tie” morphology.

Answer 7

Desmoplastic trichoepithelioma

Microcystic adnexal carcinoma

Morpheaform BCC

Eruptive syringomas

Syringomas

Question 8

Lymphadenoma (adamantinoid trichoblastoma)

Answer 8

Tumor islands with 1-2 layers of basaloid cells peripherally and clear/inflammatory cells centrally.

Question 9

Fibrofolliculoma

Answer 9

Fibrous pink orb with radiating epithelial strands. No hair fibers.

*associated with Birt-Hogg-Dube syndrome*

Question 10

Trichofolliculoma

Answer 10

Many small hair follicles emptying into a large follicular infundibulum. Many small hair shafts.

Question 11

Trichoadenoma

Answer 11

Multiple “red doughnuts” in the dermis resembling follicular infundibulum. Often in pairs?

Question 12

Basaloid follicular hamartoma

Answer 12

Resembles infundibulocystic BCC (distinguish clinically). Can be multiple (AD-inherited) with blaschkoid distribution.

Question 13

Dilated pore of Winer

Answer 13

Resembling a dilated follicular infundibulum, with small radiationg epithelial projections.

Question 14

Pilar sheath acanthoma

Answer 14

Similar to dilated pore of Winer, but with thick acanthotic fingers

Question 15

Trichlemmoma

Answer 15

Warty-surfaced lobules of clear cells and peripheral palisading. Outlined by thick glassy eosinophilic basement membranous.

*associated with Cowden’s syndrome*

Question 16

Desmoplastic trichilemmoma

Answer 16

Smooth outline with surrounding glassy basement membrane. Centrally desmoplastic.

Question 17

Nevus sebaceus of Jadassohn (organoid nevus)

Answer 17

Broad and alopecic lesion that becomes papillomatous and hyperkeratotic after puberty.

Question 18

Sebaceous hyperplasia

Answer 18

Cluster of mature sebaceous glands around a patulous follicular opening. Nominal basaloid layer at periphery.

Question 19

Sebaceoma

Answer 19

Single nodule with varying proportions of basaloid cells (sebacoeous epithelioma) and sebocytes (sebaceous adenoma).

*associated with Muir-Torre syndrome*

Question 20

Sebaceous carcinoma

Answer 20

Atypical and infiltrative lesion with foamy cells with scalloped nuclei and buckshot spread.

Question 21

Answer 21

Pilomatricoma (low-power)

Question 22

Answer 22

Pilomatricoma (high-power)

Question 23

Answer 23

Pilomatrical carcinoma

Question 24

Answer 24

Trichoblastoma

Question 25

Answer 25

Trichoepithelioma

Question 26

Answer 26

Desmoplastic trichoepithelioma

Question 27

Answer 27

Lymphadenoma

Question 28

Answer 28

Fibrofolliculoma

Question 29

Answer 29

Trichofolliculoma

Question 30

Answer 30

Trichoadenoma

Question 31

Answer 31

Basaloid follicular hamartoma

Question 32

Answer 32

Dilated pore of Winer

Question 33

Answer 33

Pilar sheath acanthoma

Question 34

Answer 34

Trichilemmoma

Question 35

Answer 35

Desmoplastic trichilemmoma

Question 36

Answer 36

Postpubertal nevus sebaceus of Jadassohn

Question 37

Answer 37

Prepubertal nevus sebaceus of Jadassohn

Question 38

Answer 38

Sebaceous hyperplasia

Question 39

Answer 39

Sebaceoma

Question 40

Answer 40

Sebaceous carcinoma