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Volar Dermoscopy, Palmar & Plantar Melanocytic Lesions

Furrow vs ridge, one rule that triages 95% of acral pigmented lesions.

By Dr. Yehonatan KaplanPublished Updated

In brief

Acral skin reverses the dermoscopic logic of trunk and limbs, there is no pigment network because the rete ridges are flat. Instead, the dermal ridges and furrows carry pigment differently. The single most important rule: pigment in the FURROWS (parallel furrow pattern, PFP) is benign; pigment on the RIDGES (parallel ridge pattern, PRP) is acral lentiginous melanoma until proven otherwise.

Clinical content

01Anatomy refresher. Volar skin has alternating dermal ridges (with eccrine ostia visible as white dots) and furrows (deeper grooves). The eccrine ostia mark the ridges.

02Parallel furrow pattern (PFP): pigment in the furrows. Benign acral nevus. Most common pattern in pediatric/young adult acral lesions.

03Lattice-like and fibrillar variants of PFP: still benign, the pigment line is in the furrow but with cross-hatches (lattice) or short oblique strokes (fibrillar from pressure points like the heel).

04Parallel ridge pattern (PRP): pigment on the ridges (eccrine ostia visible within the dark band). Acral lentiginous melanoma. Sensitivity 86%, specificity 99% in classical Saida studies.

05Multicomponent pattern with parallel ridge: invasive acral melanoma; biopsy.

06Site-specific exception: pressure-point heel lesions can show fibrillar/parallel-ridge-like pattern from pressure-induced pigment redistribution, re-evaluate after offloading and on repeat imaging.

Key dermoscopic features

Parallel furrow pattern (PFP)
Benign acral nevus; pigment in the grooves.
Lattice-like pattern
Benign variant of PFP with cross-hatching; common on instep.
Fibrillar pattern
Pressure points (heel); short oblique pigment strokes, usually benign but re-evaluate.
Parallel ridge pattern (PRP)
Acral lentiginous melanoma; pigment on the elevated ridges.
Diffuse pigmentation with PRP
Invasive acral melanoma.
Multicomponent on acral skin
High-risk acral lesion, biopsy.
Eccrine ostia visible
White dots = ridges; useful landmark to determine ridge vs furrow.

High yield clinical points7 pearls in 3 groups

Recognition & pattern analysis

4 points
1
Furrow = benign, ridge = malignant. Single most useful rule in acral dermoscopy. Use eccrine ostia (white dots) to identify which is which.
2
Eccrine ostia mark the ridges. Find the white dots; the band of pigment they sit on is the ridge.
3
Fibrillar on heel ≠ alarm. Pressure-induced pigment redistribution at high-pressure points; re-evaluate after offloading and on repeat imaging.
4
Subungual is its own site. Acral pigmented lesions of the nail unit follow onychoscopy rules, not volar rules.

Diagnostic criteria & thresholds

1 point
1
PRP sensitivity 86%, specificity 99%. In Saida's classical studies; few features in dermoscopy match this specificity.

When to biopsy

2 points
1
Diffuse pigmentation. Loss of regular pattern with diffuse pigmentation is a multicomponent acral pattern, biopsy.
2
Pediatric acral nevi are benign. Even when relatively atypical-appearing, pediatric acral nevi rarely become melanoma; serial dermoscopy beats biopsy.

Lectures covering this topic4 lectures

AAD 2026F095 · #02
Volar Dermoscopy: Palmar and Plantar Skin Melanocytic
Nadeem Marghoob, DO
Excellence (main)DE-MAIN · #06
Acral and Nail Lesions
G. Argenziano and A. Lallas
Excellence Intl 2025DE-INTL · #04
Acral Update
Giuseppe Argenziano
Academy 2025ACAD25 · #10
Volar Lesions
Ashfaq A. Marghoob

Notable updates & conceptual milestones3 updates

Volar dermoscopy AI

2024-2026

Acral-specific AI models trained on PFP vs PRP recognition reach 88-92% concordance with expert dermoscopists.

Mucosal/volar 3-step algorithm

2024

Updated 3-step algorithm for ALM that integrates clinical history, dermoscopic pattern, and confocal, adopted by IDS 2024.

Site-specific palmoplantar density mapping

2024

Among 471 atypical palmoplantar lesions, melanoma density was highest at the heel (40%) and finger pulp (33%), the chronic-friction sites; plantar arch lesions were the hardest to read.

Bottom line

Furrow vs ridge, one rule that triages 95% of acral pigmented lesions.

7 clinical points · 3 recent updates · 5 references

Source content

AAD 2026 · F095 · #02

Volar Dermoscopy (Palmar and Plantar Skin Melanocytic)

References

Sources cited in the lecture content or that underpin the clinical points above. Verify with primary sources before practice changes.

  1. [1]
    Saida T, Miyazaki A, Oguchi S, et al. Significance of dermoscopic patterns in detecting malignant melanoma on acral volar skin: results of a multicenter study in Japan. Arch Dermatol. 2004;140(10):1233-1238.
    PubMed: 15492187· Foundational PFP vs PRP study.
  2. [2]
    Koga H, Saida T. Revised 3-step algorithm for the management of acral melanocytic lesions. Dermatology. 2011;223(3):225-231.
    DOI: 10.1159/000333303
  3. [3]
    Lallas A, Kyrgidis A, Koga H, et al. The BRAAFF checklist: a new dermoscopic algorithm for diagnosing acral melanoma. Br J Dermatol. 2015;173(4):1041-1049.
    PubMed: 26211689DOI: 10.1111/bjd.14045
  4. [4]
    Tognetti L, Cinotti E, Habougit C, et al. Site-specific palmoplantar melanoma density. Life (Basel). 2024;14(6):659.
    PubMed: 38929643DOI: 10.3390/life14060659· Among 471 atypical palmoplantar lesions: melanoma density 40% at heel and 33% at finger pulp (chronic-friction sites); plantar arch hardest to read.
  5. [5]
    Togawa Y, Nakamura Y, Kobayashi A, et al. Parallel ridge pattern fades with thickness in acral melanoma. JAAD Int. 2025;19:43-50.
    PubMed: 40688435DOI: 10.1016/j.jdin.2025.05.008· PRP peaks in in-situ acral melanoma and fades with thickness; thick lesions (>4 mm) show irregular dots, blue-gray clods, blood crusts, shiny white lines.