Severe architectural disorder is a potential pitfall in the diagnosis of small melanocytic lesions

Dermoscopy of small melanomas: just miniaturized dermoscopy?

BACKGROUND

Small malignant melanomas (MMs) are usually MMs in an initial growth phase, deserving attention by the clinician aiming at an early diagnosis.

OBJECTIVES

To identify clues for early diagnosis of small MMs, by comparing the dermoscopic features of MMs < 4 mm (micromelanomas) with those of larger MMs.

METHODS

Our database consists of dermoscopic images of 482 MMs, which have been retrieved and measured digitally. The ABCD (asymmetry, border, colour, dimension) and 7-point criteria were evaluated for the whole database by three expert dermoscopists, whereas the main dermoscopic pattern was assessed only for micromelanomas. The dermoscopic aspects were correlated to clinical and histological features.

RESULTS

Most 7-point and ABCD scores, and criteria referring to micromelanomas, differed from those of the MM database as a whole. Lesion asymmetry, number of colours, blue-whitish veil, atypical vessels, irregular globules/dots and regression increased according to MM diameter. An inverse trend was observed for atypical network and irregular pigmentation, which were more frequently observed in micromelanomas than in larger ones. Among the 22 micromelanomas, 12 lesions were in situ, whereas the other 10 were 0·2-2 mm thick. The clinical and dermoscopic characteristics of the two groups were similar.

CONCLUSIONS

Micromelanomas are not a rarity. However, the clinician should be aware of the fact that the majority of them lack most of the dermoscopic features presented by larger lesions.

Clinico-pathological impact of fibroplasia in melanocytic nevi: a critical revision of 209 cases

Fibroplasia is a peculiar stromal reaction at the base of melanocytic lesions, particularly observed in so-called dysplastic nevi. This study evaluates a series of clinico-pathological features in nevi with fibroplasia, their frequence in comparison to usual nevi, and the association of fibroplasia with the risk for the development of melanoma. A total of 209 consecutive nevi showing fibroplasia, belonging to 203 patients, was reviewed. Nevi with fibroplasia were more frequent in men, about half of the lesions belonged to patients aged 11-40 years, and the highest number (52%) were located on the posterior trunk. Lesions 6 mm or greater were 152 (72.73%). Junctional and compound nevi were 52 (24.8%), and 157 (75.2%), respectively. Inflammatory infiltrate was present in 67.8% of cases, melanophages in 56.4%, a lentiginous pattern in 31.1%, focal pagetoid infiltration in three lesions. Nevi with fibroplasia constituted 4.27% of all junctional and compound nevi diagnosed in the same period. A total of 23 patients (11.3%) had a personal history of melanoma. The total number of nevi excised from the 203 patients ranged between 1 and 21, and significantly correlated with the patient's personal history of melanoma (p < 0.001). Fibroplasia is relatively infrequent in melanocytic nevi, it does not appear related to a process of senescence of the lesion, and does not represent a particularly strong predictor of risk of melanoma.