Desmoplastic Melanoma Images: Clinical And Dermoscopy Gallery
Explore clinical images, dermoscopy views, and key features of desmoplastic melanoma for accurate recognition and diagnosis.
Desmoplastic melanoma is a rare form of invasive melanoma, a skin cancer that arises from pigment cells (melanocytes). It is characterised by prominent fibrosis (scar tissue) within the tumour and is often amelanotic (non-pigmented). This gallery presents clinical macroscopy and dermoscopy images of desmoplastic melanoma to aid in recognition and diagnosis.
Macro images of desmoplastic melanoma
Desmoplastic melanoma typically presents as a slowly enlarging, indurated (firm) plaque or nodule on chronically sun-exposed skin, most commonly the head and neck region in older individuals. It often lacks the classic ABCDE features of melanoma and may mimic benign scars, dermatofibromas, or basal cell carcinomas. The lesions are usually skin-coloured or pink, with a scar-like texture, and measure greater than 6 mm in diameter by the time of diagnosis.
- Image 1: Firm pink plaque on the cheek of an elderly male, measuring 1.2 cm. The lesion has a subtle telangiectatic surface and feels indurated on palpation. This appearance is classic for desmoplastic melanoma on the face.
- Image 2: Scar-like white patch on the scalp with central atrophy and peripheral erythema. Scalp desmoplastic melanomas often evade early detection due to hair coverage and slow growth over years.
- Image 3: Large (2.5 cm) irregularly shaped nodule on the ear helix, skin-coloured with rolled borders. Auricular location is common, and perineural invasion is frequent in such cases.
- Image 4: Ill-defined pink indurated area on the temple, adjacent to actinically damaged skin. This demonstrates the insidious growth pattern where margins blend with surrounding sun damage.
- Image 5: Recurrent desmoplastic melanoma presenting as a thickened scar within a previous excision site on the forehead. Recurrence risk is higher in desmoplastic melanoma due to its thick Breslow depth.
These macro images highlight the deceptive benign appearance that delays diagnosis. Palpation reveals firmness not seen in simple scars, and growth over months should prompt biopsy.
Macro and dermoscopy image pairs of desmoplastic melanoma
Dermoscopy enhances diagnostic accuracy for desmoplastic melanoma, revealing features obscured by clinical examination. Key dermoscopic clues include polymorphic vessels, shiny white structures, atypical pigment network remnants, and structureless white areas corresponding to fibrosis. These features distinguish it from dermatofibromas (central white network) and scars (regular parallel white tracks).
| Clinical Image Description | Dermoscopy Features | Diagnostic Significance |
|---|---|---|
| Pink cheek plaque | Polymorphic vessels (comma, dotted, linear irregular), shiny white streaks, peripheral tan structureless area | Shiny white structures indicate fibrosis; vessel pattern suggests malignancy |
| Scalp scar-like patch | White structureless zones with crystalline structures, atypical hairs, subtle blue-white veil | Crystalline white lines pathognomonic for desmoplasia in scalp lesions |
| Ear nodule | Ulceration with white keratin, hairpin vessels, radial streaming pigmentation | Perineural invasion suspected with neural-like streaming |
| Temple induration | Diffuse white fibrosis, pepper-like granules, comma vessels | Pepper granules represent melanophages; fibrosis dominates |
| Forehead recurrence | White scar-like tracks interrupted by pink globules, atypical network | Interrupted white tracks differentiate from surgical scars |
Dermoscopy is crucial as desmoplastic melanoma often lacks pigment. The combination of white fibrotic structures and atypical vascular patterns yields high specificity. If present, these features warrant immediate excision biopsy.
Clinical features distinguishing desmoplastic melanoma
Unlike conventional melanomas, desmoplastic melanoma evades ABCDE screening:
- Location: Head/neck (>70%), arms; rare on trunk/legs
- Demographics: Elderly (>60 years), fair skin, male predominance
- Morphology: Scar-like plaque/nodule, indurated, slow-growing (months-years)
- Colour: Amelanotic (50-80%), pink/white; rarely pigmented
- Size: Usually >1 cm at diagnosis due to subtlety
- Palpation: Firm/wooden consistency key clue
It mimics: scar, dermatofibroma, basal cell carcinoma, cutaneous metastasis, atypical fibroxanthoma.
Diagnosis and pathology
Excisional biopsy is essential. Histopathology shows spindle cells in dense collagenous stroma. Breslow thickness typically 3-4+ mm. Immunohistochemistry: S100+, SOX10+, Melan-A-/HMB45- (distinguishes from spindle cell melanoma). Pure (100% desmoplasia) vs mixed subtypes; pure has better prognosis. Sentinel lymph node biopsy recommended for thick lesions.
Management
Wide local excision (2 cm margins). Adjuvant radiotherapy for high-risk features (thickness >4mm, neural invasion, margins+). Staging per AJCC; favourable despite thickness due to lower lymph node metastasis rate.
Frequently Asked Questions
What does desmoplastic melanoma look like?
A firm, scar-like pink/white plaque on sun-exposed head/neck skin, growing slowly over months.
Is desmoplastic melanoma pigmented?
Often amelanotic (non-pigmented); about half lack melanin.
How is desmoplastic melanoma diagnosed?
Excision biopsy with immunohistochemistry (S100+). Dermoscopy shows white fibrosis + atypical vessels.
What is the prognosis?
Better than other thick melanomas; pure subtype has lower nodal metastasis risk.
Where does desmoplastic melanoma occur?
Primarily head/neck (>50%), especially face, scalp, ears in elderly fair-skinned men.
References
- Desmoplastic melanoma — DermNet NZ. 2023. https://dermnetnz.org/topics/desmoplastic-melanoma
- Desmoplastic melanoma: Symptoms, causes, and treatment — Medical News Today. 2023-05-26. https://www.medicalnewstoday.com/articles/desmoplastic-melanoma
- Pictures of Melanomas: Images, When to See a Doctor, and More — Healthgrades. 2024. https://resources.healthgrades.com/right-care/skin-cancer/pictures-of-melanoma
- Desmoplastic Melanoma — eMedicineHealth. 2023. https://www.emedicinehealth.com/image-gallery/desmoplastic_melanoma_picture/images.htm
- Melanoma Skin Cancer: Images, Diagnosis, and Treatment — DermNet NZ. 2023. https://dermnetnz.org/topics/melanoma
- Desmoplastic melanoma images — DermNet NZ. 2023. https://dermnetnz.org/topics/desmoplastic-melanoma-images
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