Insitu malignant melanoma

1. Insitu malignant melanoma Pagetoid spread of malignant melanocytes (arrows) confined to the epidermis Lymphocytes in dermis

2. Invasive Malignant melanoma Mitoses –prognostic factor 3 non pigmented pigmented Melanoma cells are large with round nuclei containing nucleolus Mitoses (arrow)

3. Ulcerated nodular melanoma Ulceration -prognostic factor 4 Ulceration

4. Sentinel Node Biopsy • Performed in patients with - invasive melanoma of ≥1mm Breslow thickness or Clark level IV - no clinically evident metastatic disease • +Sentinel node is the most important prognostic factor in invasive melanoma ≥1mm Breslow thickness

5. Sentinel node: metastatic melanoma Prognostic factor 5 Lymph node Melanoma

6. Melanoma- 6 Major Prognostic Factors in TNM staging • Breslow thickness • Clark level • Mitoses • Ulceration • Sentinel lymph node status • Satellite nodule (intransit metastasis) Important slide

7. SKIN RASHES Clinicopathologic Review Session W

8. How to Describe a Lesion SCALDA – Loo Very important • Size • Color • Arrangement (configuration) • Lesion morphology • Distribution • Always check hair, nail, mucosa, intertriginous areas

9. Arrangement (configuration) - manner in which lesions relate to one another Grouped Annular Geographic Linear SCALDA

10. Lesional morphology • Macule/patch: ≤/>1cm flat lesion • Papule/plaque: ≤/> 1cm raised lesion • Nodule: >1 cm raised lesion, rounded surface • Vesicle/bulla: ≤/> 1 cm blister • Surface - scale/crust/excoriated – Scale: dry/flaky surface - Crust (Scab): wet, dried serum, pus or blood - Excoriation: scratching SCALDA

11. Rashes for Clinicians • Dermatitis (Eczema) • Papulosquamous lesions • Vasculitis, cutaneous manifestations of systemic diseases • Drug reactions • Vesiculo-bullous diseases • Infections • Acne

12. Rashes - Role of a pathologist • 3-5% of lesions -difficult for clinicians -G od -O nly -K nows • Biopsy -Single Most Important Test

13. Biopsy Methods Excisional B Tumor Incisional B Rash Punch B Shave B

14. Punch biopsy 3mm 4mm 6mm

15. Selection of Punch Biopsy- Selection of Biopsy Rash • Biopsy early/well developed rashes • Avoid - excoriated lesions, ulcers - Burned out late lesions - Sec. infected lesions • Biopsy periphery of lesion including normal skin

16. Biopsy transportation BiopsyF ixatives • Universal fixative in Pathology is 10% neutral buffered formalin • For immunofluorescence testing -Michel’s transporting medium

17. Skin: Histology Epidermis and Dermis • Stratum Corneum • Stratum Granulosum • Stratum Spinosum • Stratum Basalis

18. 1. DERMATITIS (eczema) • Non infective inflammatory reaction of the skin affecting the epidermis and dermis due to a variety of causes.

19. Dermatitis: Common Types & Pathogenesis • Allergic contact dermatitis - Type 1V hypersensitivity reaction • Irritant contact dermatitis - direct toxic effect, non immune • Nummular dermatitis -unknown cause • Atopic dermatitis - children- Type 1 (IgE mediated) hypersensitivity reaction

20. Dermatitis: Common Types & Pathogenesis • Seborrheic dermatitis - Pityrosporum ovale • Stasis dermatitis - venous stasis • Lichen Simplex Chronicus -repeated rubbing and scratching of skin

21. A question W chronic from acute dermatitis A) Lichenification B) Erythema and edema C) Vesicles and blisters D) Exudation E) Crusting

22. Dermatitis – 3 phases Pathophysiology 1) Acute dermatitis 2) Subacute dermatitis 3) Chronic dermatitis

23. Dermatitis – 3 phases Pathophysiology 1) Acute dermatitis - spongiosis, microvesicles (pain, erythema, edema, vesicles, itchy) 2) Subacute dermatitis - scaling, crusting 3) Chronic dermatitis - scaling and thickening of skin with increased skin markings (lichenification, related to repeated scratching) Important Integration slide

24. Acute Dermatitis Acute allergic contact dermatitis Poison Ivy

25. Acute dermatitis Acute atopic dermatitis

26. Subacute dermatitis Subacute atopic dermatitis

27. Chronic dermatitis Lichenification

28. Chronic dermatitis Lichenification

29. Acute D SPONGIOSIS: intercellular edema (A), microvesicles (B), dermal inflammation (C) A B C A Normal skin

30. Chronic D Lichenification: hyperkeratosis (A), acanthosis (B), dermal fibrosis (C) A B C Thickening of all layers of skin Normal skin

31. What single feature distinguishes chronic from acute dermatitis A) Lichenification B) Erythema and edema C) Vesicles and blisters D) Exudation E) Crusting Answer: A

32. 2. PAPULOSQUAMOUS DISEASES • A group of etiologically unrelated skin disorders where lesions share a common clinical appearance -Papular, but may contain other forms, - well demarcated - scaly • Psoriasis, Lichen planus and Pityriasis rosea

33. Dermatitis vs Papulosquamous D B A

34. Psoriasis: clinical forms • Psoriasis vulgaris - most common type • Guttate psoriasis • Pustular psoriasis • Erythrodermic psoriasis • Psoriatic nails • Psoriatic arthritis

35. Psoriasis Vulgaris vs Guttate Psoriasis Generalized, rapid onset, follow strep throat Discrete erythematous plaques, silvery white scale multiple smaller erythematous plaques, scale minimal

36. A Psoriasis Vulgaris case • Well circumscribed Erythematous (salmon pink) papules/plaques with silvery white scale • Kobner phenomenon: lesions appear at site of repeated trauma • Auspitz’s sign -removal of scale results in minute bleeding points

37. Auspitz sign Pinpoint bleeding areas where scale is removed

38. What is this phenomenon -Koebner P

39. Psoriasis Vulgaris - Pathology Parakeratosis (silvery scale) Acanthosis Dilated vessels, dermal inflammation Inflammation and epidermal proliferation

40. Study Psoriasis -under the microscope A B C For information only

41. Psoriasis Pathophysiology • Increased epidermal turn over or shortened cell cycle from 311 to 36 hours which results in 28 times the normal production of epidermal cells of psoriatic skin • T cell mediated, CD4 T cells mediate epidermal proliferation • Stratum corneum is abnormally formed • Cause unclear, role for genetic and environmental factors

42. Pityriasis Rosea

43. Pityriasis Rosea • Common, self limiting, disease of children • Cause is unknown, but may follow various infections, debate regarding HHV-7 (viral) • Herald patch -first lesion, larger • Symmetrial smaller lesions appear within 2 weeks on trunk, thighs and arms -christmas tree -like arrangement • Mostly a clinical diagnosis, biopsy rarely needed

44. Pityriasis Rosea Herald patch and multiple round or oval macules with fine scale at the periphery of each lesion CHRISTMAS TREE Herald patch

45. Lichen Planus (5 P’s) • Purple (violaceous) • Pruritic • Polygonal • Planar • Papules x Flat topped

46. Lichen Planus • Acute or chronic inflammatory dermatosis involving skin and mucous membrane • Idiopathic in most cases • Possible HLA associated genetic susceptibility

47. Lichen Planus Location Skin -flexural surfaces, wrists Mucous membrane-mouth Nail Hair loss Koebner phenomenon: lesions appear at site of trauma Hepatitis C has been associated

48. Lichen Planus -Pathology Hyperkeratosis (Scale) Irregular acanthosis Basal cell damage Band of lymphocytes Inflammatory injury to the basal cells of the epidermis leads to epidermal thickening and scaling

49. Study Lichen Planus: under the microscope A B C D For information only

50. Prepare • Vasculitis -common types, causes • Cutaneous manifestations of systemic disease - Diabetes - Lupus - Dermatomyositis • Drug reactions - common types • All signs and phenomenon • Acne