The significance of crystalline/chrysalis structures in the diagnosis of melanocytic and nonmelanocytic lesions.
BACKGROUND
Crystalline/chrysalis structures (CS) are white shiny streaks that can only be seen with polarized dermatoscopy.


OBJECTIVE
We sought to estimate the prevalence and assess the clinical significance of CS in melanocytic and nonmelanocytic lesions.


METHODS
This was a prospective observational study in which dermatoscopic assessment of lesions was recorded in consecutive patients examined during a 6-month period. In addition, a data set of biopsy-proven melanomas was retrospectively analyzed.


RESULTS
In all, 11,225 lesions in 881 patients were prospectively examined. Retrospectively, 229 melanomas imaged with polarized dermatoscopy were analyzed. In the prospective data set, a median of 12.7 lesions (range, 1-54) were evaluated per patient. None of clinically diagnosed Clark nevi (n = 9750, 86.8%) demonstrated CS. Overall, CS were observed in 206 (1.8%) lesions, most commonly dermatofibromas and scars among nonbiopsied lesions. A total of 265 (2.4%) lesions were biopsied, including 20 melanomas and 36 nevi. Among biopsied malignant lesions, CS were most commonly observed in basal cell carcinoma (47.6%) and invasive melanomas (84.6%). Melanomas were more likely to have CS than biopsied nevi (odds ratio = 9.7, 95% confidence interval 2.7-34.1). In the retrospective data set, CS were more commonly observed among invasive melanomas (41%) compared with in situ melanomas (17%) (odds ratio = 3.4, 95% confidence interval 1.9-6.3, P < .001). The prevalence of CS correlated with increased melanoma thickness (P = .001).


CONCLUSIONS
Biopsied lesions represent a small percentage of the total number of lesions evaluated.


CONCLUSIONS
Among biopsied malignant lesions, CS are most commonly observed in basal cell carcinoma and invasive melanomas and rarely seen in nevi. In melanoma, CS may reflect increased tumor thickness and progression.
Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York 10022, USA.
Yevgeniy
Y
Balagula
Ralph P
RP
Braun
Harold S
HS
Rabinovitz
Stephen W
SW
Dusza
Alon
A
Scope
Tracey N
TN
Liebman
Ines
I
Mordente
Katherine
K
Siamas
Ashfaq A
AA
Marghoob
D002278:Carcinoma in Situ / Q000453:epidemiology / Q000473:pathology; D002280:Basal Cell Carcinoma / Q000453:epidemiology / Q000473:pathology*; D003460:Crystallization; D046169:Dermoscopy; D018219:Histiocytoma, Benign Fibrous / Q000453:epidemiology / Q000473:pathology*; D006801:Humans; D017492:Keratosis, Seborrheic / Q000453:epidemiology / Q000473:pathology*; D008545:Melanoma / Q000453:epidemiology / Q000473:pathology*; D009361:Neoplasm Invasiveness / Q000473:pathology; D009508:Nevus, Pigmented / Q000453:epidemiology / Q000473:pathology*; D015995:Prevalence; D011446:Prospective Studies; D012189:Retrospective Studies; D012867:Skin / Q000737:chemistry / Q000473:pathology; D012878:Skin Neoplasms / Q000453:epidemiology / Q000473:pathology*