Dermoscopy · Skin Lesion

What it does

Dermoscopy reads one skin lesion seen through a dermatoscope. Upload one to four dermoscopic images of the lesion, polarised or non-polarised, with a clinical close-up and the patient's age, sex, body site and history if you have them. The run checks that each image is usable, then reads the lesion as a whole.

It returns a ranked differential (melanoma, naevus, basal cell carcinoma, squamous cell carcinoma or intraepidermal carcinoma, actinic keratosis, seborrhoeic keratosis or solar lentigo, dermatofibroma, vascular lesions and others) with calibrated probabilities and a malignancy probability. It names the dermoscopic structures it sees, in the terms of the International Dermoscopy Society (IDS), and derives a 7-point checklist score from them. A management class closes the read: excision or biopsy, referral, review by sequential dermoscopy at three months, or reassurance.

Intended use

Decision support for the clinician holding the dermatoscope: a dermatologist, a dermatology resident, or a GP or nurse working in a skin-cancer or teledermoscopy pathway. The triage class is set to favour sensitivity, so a lesion is more likely to be sent for review than reassured. A reported history of change overrides a reassuring score.

Who it is for

Dermatologists, dermatology residents, GPs with a dermatoscope, skin-cancer clinic nurses and teledermatology services. Developers use the same run to add lesion analysis to a teledermoscopy platform or a clinic photo archive.

Accepted input

• DICOM Dermoscopic Photography Image (DMS) objects, or JPEG, PNG, HEIC and WebP images from dermatoscopes and phone-mounted dermatoscopes.
• One lesion per request: one to four dermoscopic images, plus an optional clinical close-up.
• Prior images of the same lesion in prior_files for the change section.

Requirements

Requirement	Why
Lesion centred, at least about 600 px on the short side	Structures such as streaks, dots and vessels need resolution
Body site (supplied or estimated)	Acral, nail, mucosal and facial lesions follow their own pattern rules
Calibration sticker or ruler	Diameters and areas in mm; otherwise pixel values are returned and flagged
Little hair, ink, ruler marks or bubbles over the lesion	These artefacts are reported, and the quality check asks for a retake when they obscure the lesion

Optional context

Age, sex, body site, duration, symptoms (itch, bleeding), history of change, personal or family history of melanoma and Fitzpatrick type in clinical_context. A clinical close-up and these fields refine the differential.

The result

A JSON result with a lesion_id, a coded body site, the ranked differential[] and a management class.

Section	Content
Differential diagnosis	Ranked diagnoses with calibrated probabilities over 8 diagnostic classes, coded in SNOMED CT and ICD-10/ICD-11
Triage	Urgent referral or excision, routine referral, short-term sequential monitoring or reassurance, with the malignancy probability
Lesion segmentation	Lesion mask, area, maximum diameter, asymmetry and border-irregularity metrics
Dermoscopic structures	Pigment network, negative network, streaks, milia-like cysts, globules and dots, blue-white veil, regression structures and vessels, with masks and the 7-point checklist score
Change since prior	Registered comparison with the earlier image: growth, new structures, asymmetric enlargement and colour change, with an excise or keep-monitoring suggestion
Draft report	Opt-in (options.report): an English narrative that interprets the result for the reader (findings, impression, limitations); every number is checked against the findings

Standards

• Terminology: IDS dermoscopy terminology, third consensus (Kittler et al., JAAD 2016).
• Scores: 7-point checklist (Argenziano 1998); ABCD rule and total dermoscopy score (Stolz 1994); TADA triage algorithm (Rogers 2016) as a rule-based cross-check of the triage class.
• Referral: the local suspected-cancer pathway, for example NICE NG12.
• Coding: ISIC diagnosis hierarchy, SNOMED CT, ICD-10 and ICD-11; body site in DICOM CID 4029 Dermatology Anatomic Site.
• DICOM and FHIR: SEG for lesion and structure masks, SR TID 1500 with TID 1410 planar measurements, Key Object Selection for the images that drove the read, Encapsulated PDF; FHIR DiagnosticReport, Observation and BodyStructure so the same lesion can be found again at follow-up.