Abstract:
Introduction. Cutaneous malignant melanoma exhibits marked heterogeneity in clinical behaviour
and histopathologic appearance. Although tumour thickness, Clark level, and invasive growth patterns
remain key prognostic indicators, the significance of melanocytic pigment synthesis remains
incompletely defined. Amelanotic melanomas are often associated with delayed diagnosis and poorer
outcomes. Loss of pigmentation may reflect melanocytic dedifferentiation, altered melanogenesis
pathways, and enhanced invasive potential. The relationship between pigmentation status and
established markers of aggressiveness has not been consistently quantified. This study investigates the
relationship between pigmentation status and histopathologic indicators of tumour aggressiveness in
superficial spreading melanoma.
Materials and Methods. A retrospective analysis was performed on 47 cases of superficial spreading
melanoma from the Oncology Institute of Chisinau. Histopathologic evaluation included tumour
thickness, Clark level, ulceration, mitotic activity, microsatellitosis, pigmentation status,
lymphovascular invasion, perineural invasion, and lymph node involvement. Pigmentation was
assessed on hematoxylin–eosin–stained sections and classified as pigmented or non-pigmented.
Correlations were analysed using Pearson correlation coefficients, with significance set at p ≤ 0.05.
Results. The cohort included 47 patients (mean age 65.6 ± 12.15 years), comprising 24 females
(51.1%) and 23 males (48.9%). Pigmented melanomas accounted for 34 cases (72.3%), while 13 cases
(27.7%) were non-pigmented. Pigmentation status demonstrated statistically significant inverse
correlations with several established histopathologic markers of tumour aggressiveness. A moderate
negative correlation was observed between pigmentation and tumour thickness (r = −0.42, p = 0.0001),
indicating that non-pigmented melanomas were associated with increased tumour thickness. Similarly,
pigmentation was inversely correlated with Clark level (r = −0.38, p = 0.001). Pigmentation showed
significant negative associations with both, lymphovascular invasion (r = −0.26, p = 0.04) and
perineural invasion (r = −0.24, p = 0.05), suggesting a higher frequency of invasive features in nonpigmented tumours. No other parameters showed significant correlations.
Conclusions. Loss of pigmentation in superficial spreading melanoma is associated with a more
aggressive histopathologic profile, including greater tumour thickness, higher Clark level, and
increased invasive features. Pigmentation status may serve as an additional prognostic indicator and
warrants careful evaluation in routine histopathologic assessment.
