The natural evolution of melanocytic nevi is a complex, multifactorial process that can be studie... more The natural evolution of melanocytic nevi is a complex, multifactorial process that can be studied by monitoring nevi on a long-term basis. To assess the evolution pathway of Spitz nevi, lesions with clinical and dermoscopic features suggestive of Spitz nevi were monitored and baseline and follow-up images compared. Sixty-four patients (mean age 10.4 years) with lesions suggestive of Spitz nevi were included. Lesions were monitored for a mean follow-up period of 25 months. Upon side-by-side evaluation of baseline and follow-up images, 51 (79.7%) lesions showed an involution pattern and 13 (20.3%) lesions showed a growing or stable pattern. No significant differences were found between growing and involving lesions in terms of patient age and sex and the location and palpability of lesions. The great majority of growing lesions were pigmented or partially pigmented (92.3%), whereas 47.1% of lesions in involution were amelanotic (p = 0.005). In this series of lesions clinically and dermoscopically diagnosed as Spitz nevi, spontaneous involution seems to be the most common biologic behavior.
Among the pigmented lesions with a central area of scar, we found a group of cases histologically... more Among the pigmented lesions with a central area of scar, we found a group of cases histologically characterized by striking architectural alteration of the melanocytic component, but with no cytological atypia and mitotically quiescent. The aim of the current study was to assess the biological nature of such lesions. We selected 19 of these melanocytic neoplasms that had the following characteristics: (a) a clinically evident whitish central area suggestive of regression (with no history of a previous surgical procedure or trauma), (b) histological features of fibrous scar-like tissue at the center of the lesion, (c) the presence of large, confluent and unusually shaped melanocytic nests at the dermoepidermal junction and in the dermis, (d) a pagetoid spread of melanocytes above the epidermal basal layer and (e) remnants of nevus tissue at the border of the scar. The lesions showed no evidence of cytological atypia, expansive nodules of melanocytes, significant numbers of mitoses or cellular necrosis. All the cases have been followed up and none have recurred or metastasized. Histologically, these neoplasms have important similarities with the so-called recurrent nevus, nevi on lichen sclerosus and nevi developed during or following cutaneous inflammatory and sclerosing processes. The origin of the scar in each case was obscure but was probably related to minor unnoticed trauma or to chronic friction on a nevus. In few cases, the fibrosis was probably the result of partial regression of the nevus or a sequel to folliculitis. The pseudomelanomatous features appear to be related to the presence of the scar, as already reported for nevi that are involved in fibrotic or scarring processes. In our study, the nevi involved in the fibrotic process were congenital nevi and common or dysplastic nevi. One case was a Spitz nevus. From our data we concluded that, despite their worrisome clinical and histological aspect, the lesions described in this case series were most probably benign melanocytic nevi, involved by a fibrotic process combined with pseudomelanomatous proliferation. The lack of cytological atypia, mitoses and expansive nodules allowed us to differentiate these lesions from regressing melanomas.
The natural evolution of melanocytic nevi is a complex, multifactorial process that can be studie... more The natural evolution of melanocytic nevi is a complex, multifactorial process that can be studied by monitoring nevi on a long-term basis. To assess the evolution pathway of Spitz nevi, lesions with clinical and dermoscopic features suggestive of Spitz nevi were monitored and baseline and follow-up images compared. Sixty-four patients (mean age 10.4 years) with lesions suggestive of Spitz nevi were included. Lesions were monitored for a mean follow-up period of 25 months. Upon side-by-side evaluation of baseline and follow-up images, 51 (79.7%) lesions showed an involution pattern and 13 (20.3%) lesions showed a growing or stable pattern. No significant differences were found between growing and involving lesions in terms of patient age and sex and the location and palpability of lesions. The great majority of growing lesions were pigmented or partially pigmented (92.3%), whereas 47.1% of lesions in involution were amelanotic (p = 0.005). In this series of lesions clinically and dermoscopically diagnosed as Spitz nevi, spontaneous involution seems to be the most common biologic behavior.
Among the pigmented lesions with a central area of scar, we found a group of cases histologically... more Among the pigmented lesions with a central area of scar, we found a group of cases histologically characterized by striking architectural alteration of the melanocytic component, but with no cytological atypia and mitotically quiescent. The aim of the current study was to assess the biological nature of such lesions. We selected 19 of these melanocytic neoplasms that had the following characteristics: (a) a clinically evident whitish central area suggestive of regression (with no history of a previous surgical procedure or trauma), (b) histological features of fibrous scar-like tissue at the center of the lesion, (c) the presence of large, confluent and unusually shaped melanocytic nests at the dermoepidermal junction and in the dermis, (d) a pagetoid spread of melanocytes above the epidermal basal layer and (e) remnants of nevus tissue at the border of the scar. The lesions showed no evidence of cytological atypia, expansive nodules of melanocytes, significant numbers of mitoses or cellular necrosis. All the cases have been followed up and none have recurred or metastasized. Histologically, these neoplasms have important similarities with the so-called recurrent nevus, nevi on lichen sclerosus and nevi developed during or following cutaneous inflammatory and sclerosing processes. The origin of the scar in each case was obscure but was probably related to minor unnoticed trauma or to chronic friction on a nevus. In few cases, the fibrosis was probably the result of partial regression of the nevus or a sequel to folliculitis. The pseudomelanomatous features appear to be related to the presence of the scar, as already reported for nevi that are involved in fibrotic or scarring processes. In our study, the nevi involved in the fibrotic process were congenital nevi and common or dysplastic nevi. One case was a Spitz nevus. From our data we concluded that, despite their worrisome clinical and histological aspect, the lesions described in this case series were most probably benign melanocytic nevi, involved by a fibrotic process combined with pseudomelanomatous proliferation. The lack of cytological atypia, mitoses and expansive nodules allowed us to differentiate these lesions from regressing melanomas.
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Papers by P. Broganelli