Histopathological and SIAscopic Correlation of Pigmented Skin Lesions Professor Sujatha Fernando MBBS(Hon), MSc(London, Distinction), FRSTM&H, FRCPA, FIAC, FACTM Senior Consultant in Anatomical Pathology, Cytopathology, Fine Needle Aspiration and Tropical Pathology, University Affiliations University of Western Sydney, Charles Sturt University School of Dentistry and Health Sciences University of Sydney, School of Rural Health
Co Authors Dr Koh Fong Seen, Anatomical Pathology Registrar, Southern IML (SONIC) Pathology. Ms Anna Durie, Senior Medical Technologist, Southern IML (SONIC) Pathology. Dr Anne Gilroy, CEO and Director Rural GP Network and Senior Lecturer, University of Western Sydney.
Clinical diagnosis of atypical naevomelanocytic lesions including malignant melanoma continues to be challenging with many diagnostic tools devised. Most popular is dermatoscopy or skin surface microscopy and more recently in vivo confocal microscopy.
Histology of Normal Skin
Disorders of Melanocytes Benign Atypical or Dysplastic Malignant Melanoma
Spectrophotometric Intracutaneous Analysis (SIA) Is a new imaging technique. It claims to analyse rapidly and with greater accuracy pigmented skin lesions, eliminating the need for operator dependent and subjective nature of dermatoscopy.
SIAscope The SIAscope probes the skin spectrally over an area of 24 x 24mm with radiation ranging from 400-1000nm using a 24mm handset. The spectrally filtered images are fed into the computer. The computer analyses the microarchitecture of the skin such as the melanin content, dermal collagen erythematous blush with blood displacement.
A previous study by Moncrieff et.al (Universities of Cambridge and Birmingham) analysed 438 pigmented lesions referred by dermatologists and plastic surgeons over the period of one year. We commenced a prospective study to compare their results with a population of patients attending a skin clinic in rural NSW, referred by general practitioners.
SIAgraph of a superficial spreading melanoma from the Moncrieff et.al study (vertical growth phase, 2.5mm Breslow thickness, Clark s level IV) A. Colour SIAgraph shows dermatoscopic view, especially blue-grey veil. Total melanin SIAgraph (black=melanin) enhances dermatoscopic criteria such as branched streaking and pseudopodia. B. Blood SIAgraph (red=blood). The blood displacement is seen as a white area in the vertical growth phase nodule in the centre and also less obviously at the periphery at 9 o clock (circled). The erythematous blush is quite striking in this lesion. C. Collagen SIAgraph (white=collagen). The collagen hole is very large in the centre of this lesion. There is also a small collagen hole at the periphery at 9 o clock (circled). D. Dermal melanin SIAgraph (blue=dermal melanin present). There are large quantities of dermal melanin irregularly distributed in this lesion. There is also a separate focus at the periphery at 9 o clock (circled).
A total of 1014 patients (238 in the 1 st year, 776 in the 2 nd year), attending skin clinics with pigmented skin lesions, were questioned regarding: Change in colour Change in size and shape Change in sensation Bleeding and inflammation Details of size, site of lesion, age, sex, name and medical record number were entered into a data base SIAscopy performed prior to excision SIAgraph with patient demographic data accompanied the biopsies for histopathologic examination
Ephelis Sex M Age 44 Size: 1mm. Site: Left forearm. x200 x400
Lentigo Sex M Age 46 Size:. 6 x 6mm. Site: Occipital scalp. x20 x400
Junctional Naevus Sex M Age 28 Size: 3 x 1.5mm. Site: Left flank.. x40 x200
Blue Naevus Sex F Age 65 Size: 17 x 8 x 2mm. Site: Mole on scalp.? Blue grey veil No Collogen holes x200 x400
Compound Naevus Sex F Age 41 Size: 4mm. Site: Left anterior thigh. x200 x400
Dermal Naevus Sex F Age 32 Size: 4 X 4mm. Site: Left arm. x100 x400
Pigmented Naevus of Reed Sex F Age 16 Size: 6 x 4mm to a height of 1mm. Site: Back of left thigh. No Pseudopodia No Collagen holes x100 x400
Dysplastic Naevi Mildly Dysplastic Junction Naevus Sex F Age 44 Size: 3 x 2.5mm. Site: Left upper abdominal wall. x100 x400
Dysplastic Naevi Severely Dysplastic Compound Naevus Sex M Age 41 Size: 7 x 5mm. Site: Lesion mid back. x200 x400
Malignant Melanoma Superficial Spreading (with regression) Sex F Age 39 Size: 5 x 4mm Site: Right cheek. Superficial spreading Malignant melanoma. Breslow thickness 0.6mm. Clark level 2. Irregular border (pseudopodia) No collagen holes Erythematous Blush x200 x400
Malignant Melanoma Nodular Sex F Age 45 Size: 12 x10mm Site: Right elbow. Breslow thickness 0.98mm, with associated partly regressed superficial compound naevus. Clark level 3. Blue grey veil Collagen Hole Irregular dermal melanin Erythematous blush X100 H&E x100 HMB45
Malignant Melanoma Acral Lentiginous Sex: F Age: 62 Size: 7 x 5mm. Site: Right heel. Breslow thickness 0.94mm. Clark level 4. Irregular Border (pseudopodia) Collagen Hole Absent dermal melanin Erythematous blush x400 x100 HMB45
Other Pigmented Lesions Sebhorroeic Keratosis Sex F Age 48 Size: 11 x 4mm to a depth of 1mm. Site: mid back. x40 x400
Angiokeratoma Sex F Age 24 Size: 3mm. Site: Right upper back. x200 x400
Of the 1014 pigmented skin lesions 756 naevomelanocytic 297 benign naevi 449 dysplastic naevi 10 malignant melanoma Of the remainder the most common lesion was seborrhoeic keratosis (see fig.2)
Our Study 238 CASES Naevomelanocytic Other 176 Cases 62 Cases Benign 99 Cases Dysplastic 72 Cases Malignant Melanoma 5 Case Vascular 5 Cases Seborrheic keratosis 49 Cases Dermatfibroma 1 case Basal Cell Carcinoma 2 Case Squamous Cell Carcinoma 1 case Actinic Keratosis 3 Case Bowen's Disease 1 case Ephelis 6 case Lentigo 7 Case Junctional Naevus 3 case Junctional Lentiginous Naevus 42 cases Dermal naevus Intradermal naevus 14 Cases Compund Naevus 17 Cases Blue 8 Cases Naevus of Reed 2 case Mild 50 cases Moderate 20 cases Severe 2 cases Superficial Spreading 1 case Nodular 3 cases Acral lentiginous 1 case Angiokeratoma 1 case Venous lake 1 case Haemangioma 3 cases
Moncrief
Our study first year with Moncrief study 238 CASES Naevomelanocytic Other Our study 176 Cases 62 Cases Benign 99 Cases Dysplastic 72 Cases Malignant Melanoma 5 Case Vascular 5 Cases Seborrheic keratosis 49 Cases Dermatfibroma 1 case Basal Cell Carcinoma 2 Case Squamous Cell Carcinoma 1 case Actinic Keratosis 3 Case Bowen's Disease 1 case Ephelis 6 case Lentigo 7 Case Junctional Naevus 3 case Junctional Lentiginous Naevus 42 cases Dermal naevus Intradermal naevus 14 Cases Compund Naevus 17 Cases Blue 8 Cases Naevus of Reed 2 case Mild 50 cases Moderate 20 cases Severe 2 cases Naevomelanocytic Superficial Spreading 1 case Nodular 3 cases Acral lentiginous 1 case Angiokeratoma 1 case Venous lake 1 case Haemangioma 3 cases 348 CASES Other Previous study 274 Cases 74 Cases Benign Dysplastic Malignant Melanoma Vascular Seborrheic keratosis Dermatfibroma Basal Cell Carcinoma Other 215 Cases 7 Cases 52 Cases 2 Cases 29 Cases 8 Cases 21 Cases 14 Cases Lentigo 9 cases Compound Naevus 185 cases Blue 12 cases Spitz Naevi 7 cases Mixed Naevi 2 cases Mild Moderate Severe Dysplastic Naevi 7 cases Superficial Spreading 41 cases Nodular 9 cases Acral lentiginous 2 cases Haemangioma 2 cases Courtesy of Moncrieff et al. BJD 2003
Our Study
All 10 Malignant melanoma cases demonstrated in the SIAgraph: Dermal melanin Collagen holes Erythematous blush with blood displacement Dermal melanin was the least reliable feature, as melanophages and pigment incontinence was present in other lesions Blue naevi and pigmented spindle cell naevus of Reed simulated malignant melanoma The discrepancy with our results (fig. 2) compared to Moncrief et al study illustrates perhaps the referral base of General practitioners compared to specialist dermatologists/ plastic surgeons in the UK study.
Summary Several tools have been used in the clinical diagnosis of malignant melanoma 1. Dermatoscopy most popular: Requires special training Is operator dependent High subjectivity even amongst experienced dermatologists 2. In-Vivo Confocal microscopy: Complex and expensive Filed of vision 0.5 x 0.5mm Needs special training 3. SIAscopy: Simple technique Field of vision 24 x24 mm Interpretation dependent on recognition of colour on a computer screen Expensive
Conclusion SIAscopy (although expensive) is superior to Dermatoscopy and In- Vivo Confocal microscopy in the assessment of pigmented skin lesions. Needs no special training. Further study in progress to correlate SIAscopic findings of: Dysplastic naevi Blue naevi Spindle cell naevus of Reed Other pigmented non-naevomelanocytic lesions, especially seborrhoeic keratosis Siascopy will result in more appropriate referrals for suspicious pigmented skin lesions to secondary care similar to the study by Walter et al.ref. 1
References 1. Walter FM, Morris HC, Humphrys E, Hall PN, Prevost AT, Burrows N, Bradshaw L, Wilson EC, Norris P, Walls J, Johnson M, Kinmonth AL, Emery JD. Effect of adding a diagnostic aid to best practice to manage suspicious pigmented lesions in primary care: randomised controlled trial. BMJ, 2012 Jul 4;345:e4110.doi: 10.1136/bmj.e4110.