Ch. 6 - Melanocytic neoplasms Flashcards Preview

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Flashcards in Ch. 6 - Melanocytic neoplasms Deck (57)
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1
Q

Solar lentigo

(differential?)

A

Thin rete with bulbous melanotic tips.

Consider reticulated seborrheic keratosis

2
Q

Melanotic macule

A

Broad and squared-off rete with pigment at the basal layer. No nevus component.

3
Q

Benign melanocytic nevus

A

Sharply defined, well-nested melanocyte lesion without deep mitoses and with dispersion at the deep dermal aspect.

4
Q

How can maturation be assessed in a melanocytic nevus?

A

HMB-45 immunostaining (top-heavy, loses staining in the deep component)

5
Q

What is the utility of MIB-1 in diagnosing melanocytic nevi?

A

it is an immunostaining marker found in all phases of the cell cycle (except G0) which should not stain deep melanocytic nuclei.

6
Q

Balloon cell nevus

A

Sharply defined, well-nested lesion with balloon cells and without atypia.

*Balloon chnage is a degenerative feature characterized by swelling of cellular organelles

7
Q

“Neural” nevus

A

Well-defined nevus with S-shaped spindle cells (similar to neurofibroma) and nevic corpuscles resembling Meissner corpuscles.

8
Q

Congenital nevus

A

Broad, cytologically bland nevus often associated with follicles, vessel walls, and nerves. Patchy perivascular or single-file interstitial pattern.

9
Q

Spitz nevus

A

Somewhat atypical-looking nevus with vertically oriented nests surrounded by clefts, pink Kamino bodies, and large spindle and epithelioid cells.

10
Q

What are the molecular features of Spitz nevi?

A

Most have a normal chromosome complement. Some large Spitz nevi have an 11p gain.

11
Q

Pigmented spindle cell nevus of Reed

A

Clefted, vertically oriented nevus (Spitzoid), but with a greater spindle component (less epithelioid) and smaller melanocytes.

12
Q

Acral nevus

A

Sharply nested nevus with normal maturation and some central buckshot scatter. If volar, nests can be elongated.

13
Q

“Ancient” nevus

A

Sharply defined, benign-appearing nevus with large, hyperchromatic atypia. No mitoses!

14
Q

Halo nevus

A

Sharply-nested nevus with band-like lymphoid infiltrate (intermingling melanocytes and lymphocytes, unlike in melanoma).

15
Q

Blue nevus

A

Wedged or bulbous nevus with pigment to the base and a distinctive sclerotic stroma.

16
Q

What are the key features of:

Cellular blue nevi?

Epithelioid blue nevi?

Deep penetrating nevi?

A

Cellular: Fusiform melanocytes with vesicular nuclei and prominent nucleoli.

Epithelioid: Associated with Carney complex. No sclerotic stroma.

Deep penetrating: Small hyperchromatic nuclei and smudged chromatin

17
Q

Dysplastic nevus

A

Large, oval lesion with irregular pigment, fading macular “shoulder” border, club-shaped rete hyperplasia.

18
Q

How are dysplastic nevi graded?

A

Low-grade: Atypia restricted to shoulder region

Moderate: Atypia in both shoulder and central regions.

High-grade: High-grade atypia, irregular nests.

19
Q

Junctional lentiginous nevus

A

Dysplastic-appearing nevus with club-shaped epidermal hyperplasia with restriction of nests to the tips and sides of rete.

20
Q

Recurrent nevus (pseudomelanoma)

A

Confluent, poorly nested junctional melanocytic porliferation above prior resection scar. Rule out melanoma!

21
Q

Nevus of Ota/Ito

A

Band of dendritic melanocytes in the upper dermis without sclerotic stroma.

Ota = face
Ito = shoulder
22
Q

Mongolian spot

A

Dendritic melanocytes scattered between collagen bundles in the lower half of the dermis (vs Nevus of Ito/Ota) without sclerotic stroma.

23
Q

What are the two phases of melanoma growth?

A

Lentiginous growth (in situ component) confined within the DEJ.

Vetical growth with invasion of reticular dermis and mitoses or necrosis.

24
Q

How is Breslow depth measured?

A

From the granular layer, base of an ulcer, or inner root sheath (if adnexal).

25
Q

Recite Clark’s levels.

A

I. Confined to the epidermis (in situ)

II. Into the papillary dermis

III. Into the papillary-reticular dermis interface

IV: Into the reticular dermis

V. Into the subcutaneous fat

26
Q

Superficial spreading malignant melanoma

A

Radial growth phase characterized by buckshot scatter in epidermis. Large dermal nests often with deep pigment. Lymphoplasmacytic infiltrate “wall” at base.

27
Q

Lentigo maligna

A

In situ malignant melanoma with poor nesting and confluent melanocytes and adnexal extension. Usually with solar damage and rete effacement.

28
Q

Spindle cell melanoma

Differential?

A

Cytologically spindled cells with staining for S100 and SOX10.

SLAM: Squamous cell carcinoma, Leiomyosarcoma. Atypical fibroxanthoma, Melanoma.

29
Q

Desmoplastic melanoma

A

Dense desmoplastic stroma with nodular lymphoid aggregates. Melanocytes usually spindled. S100/SOX10 reliable (but not HMB-45).

30
Q

Nodular melanoma

A

Lacks radial growth phase. No maturation or dispersion. Basal lymphoplasmacytic infiltrate.

31
Q

Regressing melanoma

A

Zones of fibrosis and melanophages. Due to inflammatory response (lentigo maligna) or genomic instability (others). An adverse prognostic indicator.

32
Q

Metastatic melanoma

A

Radially symmetrical “canonball” of atypical melanocytes. Fails to mature or disperse.

33
Q

Clear cell sarcoma

(molecular?)

A

S100+, clear and atypical soft tissue tumor thought to be a form of melanoma.

t(12;22)

34
Q
A

Solar lentigo

35
Q
A

Melanotic macule

36
Q
A

Benign melanocytic nevus

37
Q
A

Malignant melanoma (NOS)

38
Q
A

Balloon cell nevus

39
Q
A

Neural nevus

40
Q
A

Congenital nevus

41
Q
A

Spitz nevus

42
Q
A

Pigmented spindle cell nevus

43
Q
A

Acral nevus

44
Q
A

“Ancient” nevus

45
Q
A

Halo nevus

46
Q
A

Common blue nevus

47
Q
A

Dysplastic nevus

48
Q
A

Junctional lengitinous nevus

49
Q
A

Nevus of Ota/Ito

50
Q
A

Mongolian spot

51
Q
A

Superficial spreading melanoma

52
Q
A

Lentigo Maligna

53
Q
A

Spindle cell melanoma

54
Q
A

Desmoplastic melanoma

55
Q
A

Nodular melanoma

56
Q
A

Metastatic melanoma

57
Q
A

Clear cell sarcoma