Peripheral globules and growing nevi

Peripheral globules are pigmented clods situated at the outer margin of a melanocytic lesion. They are commonly associated with lesion enlargement and are frequently seen in growing nevi, particularly when they form a regular, symmetric or completely circumferential single rim. Their presence is not specific for benignity: melanoma may also display peripheral globules, especially when the globules are focal, asymmetric, tiered, morphologically atypical, or accompanied by additional melanoma-associated structures.^[1][2]

Definition and terminology

Peripheral globules are round-to-oval pigmented clods located at the periphery of a melanocytic lesion. In descriptive dermoscopic terminology, a globule corresponds to a clod.^[3] The designation “peripheral” describes location and distribution; it does not by itself imply benignity or malignancy.

The following dimensions should be assessed separately:

Distribution: completely circumferential versus focal
Arrangement: single rim versus tiered or multilayered
Morphology: relatively uniform versus variable in size, shape or color
Symmetry: symmetric versus asymmetric distribution
Context: age, anatomical site, lesion history and additional dermoscopic structures

Dermoscopic morphology

Regular peripheral globules

Relatively regular peripheral globules show limited variation in size, shape and color. They commonly form a single rim and are distributed symmetrically or completely around the lesion circumference. This configuration is most often associated with a growing melanocytic nevus.^[4][5]

Focal peripheral globules

Focal peripheral globules occupy only part of the lesion circumference. Focality alone does not establish melanoma, but it is not equivalent to the classic symmetric circumferential growth pattern. The complete lesion must be evaluated for asymmetry and additional melanoma-associated features.^[1][2]

Tiered peripheral globules

Tiered peripheral globules form more than one peripheral row or occur at different distances from the main lesion body. Observational studies found tiered arrangements more frequently in melanomas than in nevi. This is an association and not an independently validated diagnostic rule.^[1]

Morphologically atypical peripheral globules

Morphologically atypical peripheral globules vary substantially in size, shape or color. Their diagnostic relevance increases when they are focal or asymmetric or coexist with other melanoma-associated structures.^[1][2]

Diagnostic significance

Peripheral globules are associated with active enlargement of melanocytic lesions. Longitudinal studies document growth followed, in at least some nevi, by stabilization and partial or complete disappearance of the peripheral globules.^[4][5][6] The finding should therefore be interpreted as a growth-associated pattern rather than as a static marker of one diagnosis.

A regular, symmetric, single circumferential rim without additional concerning criteria is more frequently associated with nevi. Melanoma cohorts more often show focal, asymmetric, tiered or atypical peripheral globules and additional melanoma-associated structures.^[1][2] No distribution pattern proves benignity, and peripheral globules alone do not diagnose melanoma.

Clinical context

Age

Peripheral globules are commonly encountered in growing nevi in younger individuals. Their occurrence and lesion growth have also been documented in adults; age should therefore modify rather than replace morphological assessment.^[4][5][6]

Anatomical site

Anatomical location modifies interpretation. In observational melanoma cohorts, melanomas with peripheral globules were reported more frequently on the extremities.^[1][2] Site alone is insufficient for classification and should be integrated with patient age, lesion history and the complete dermoscopic pattern.

Additional dermoscopic structures

The diagnostic meaning of peripheral globules depends strongly on the remainder of the lesion. Additional melanoma-associated structures must not be discounted because a lesion also contains a peripheral rim of globules.^[1][2]

Histopathological correlation

Pigmented globules generally correlate with melanocytic nests in the epidermis or at the dermoepidermal junction. Peripheral globules are commonly interpreted as nests near the advancing peripheral edge of a growing melanocytic proliferation. This explanation is consistent with the observed growth association, but direct lesion-by-lesion histopathological correlation is limited in monitored benign nevi because many are not excised. It should not be presented as histologically proven for every lesion with peripheral globules.

Differential diagnosis and mimickers

Peripheral dots

Dots are smaller than globules/clods and may produce a superficially similar peripheral pattern. Their morphology and distribution should be described independently.

Pseudopods and streaks

Pseudopods are bulbous projections connected to a line, whereas globules are discrete clods. Regular circumferential pseudopods may form a starburst pattern; focal irregular pseudopods or streaks are evaluated differently from a rim of globules.

Peripheral satellite lesions

Separate pigmented lesions adjacent to a primary lesion should not be described as peripheral globules without confirming structural continuity and appropriate scale. Clinical correlation is essential.

Pitfalls

Do not equate peripheral globules with a benign nevus.
Do not classify focal or tiered globules as a regular circumferential growth pattern.
Do not evaluate the globules without assessing the centre and global architecture of the lesion.
Do not ignore age, anatomical site, lesion history or documented change.
Do not allow an apparently regular rim to override additional melanoma-associated structures.
Do not apply a universal management rule based solely on the presence of peripheral globules.

Evidence and limitations

The evidence base consists mainly of observational cohorts, selected image archives and retrospective or longitudinal studies rather than prospective diagnostic-accuracy studies in unselected populations. Selection bias limits the transferability of reported associations to routine populations. Available evidence supports a growth association and context-dependent morphological risk stratification, but it does not support a universal excision or monitoring rule based on peripheral globules alone.^[1][2][7]

Key take-home message

Peripheral globules are a growth-associated dermoscopic feature. A regular, symmetric, single circumferential rim without additional suspicious structures commonly supports a growing nevus pattern, whereas focal, asymmetric, tiered or morphologically atypical globules require more cautious interpretation within the complete clinical and dermoscopic context.

References

Reiter O, Chousakos E, Kurtansky N, et al. Association between the dermoscopic morphology of peripheral globules and melanocytic lesion diagnosis. J Eur Acad Dermatol Venereol. 2021;35(4):892–899. DOI · PubMed
Moraes AFA, Blumetti TCMP, Pinto C, et al. Melanoma with peripheral globules: Clinical and dermatoscopic features. J Am Acad Dermatol. 2022;87(3):567–572. DOI · PubMed
Kittler H, Marghoob AA, Argenziano G, et al. Standardization of terminology in dermoscopy/dermatoscopy: Results of the third consensus conference of the International Society of Dermoscopy. J Am Acad Dermatol. 2016;74(6):1093–1106. DOI · PubMed
Kittler H, Seltenheim M, Dawid M, Pehamberger H, Wolff K, Binder M. Frequency and characteristics of enlarging common melanocytic nevi. Arch Dermatol. 2000;136(3):316–320. DOI · PubMed
Bajaj S, Dusza SW, Marchetti MA, et al. Growth-Curve Modeling of Nevi With a Peripheral Globular Pattern. JAMA Dermatol. 2015;151(12):1338–1345. DOI · PubMed
Iluț PA, Camela E, Lallas K, et al. The Natural Evolution of Nevi with Peripheral Globules. Dermatology. 2023;239(5):760–767. DOI · PubMed
Pampín-Franco A, Gamo-Villegas R, Floristán-Muruzábal U, et al. Melanocytic lesions with peripheral globules: results of an observational prospective study in 154 high-risk melanoma patients under digital dermoscopy follow-up evaluated with reflectance confocal microscopy. J Eur Acad Dermatol Venereol. 2021;35(5):1133–1142. DOI · PubMed