Malignant melanoma arising intradermally in a small congenital nevus of an adult

On the clinical significance of cutaneous melanoma's precursors

WE CAN IDENTIFY THREE MAIN GROUPS OF CUTANEOUS PIGMENTED LESIONS THAT COULD BE REPRESENTED AS MELANOMA PRECURSORS: (a) congenital melanocytic nevi, (b) dysplastic or atypical nevi, and (c) acquired melanocytic nevi. The occurrence of melanoma in small and intermediate congenital melanocytic nevi is very uncommon, but there is a high risk in large congenital melanocytic nevi, in particular those arising in the so-called "bathing trunk" distribution. It is very important to distinguish the familial dysplastic nevus syndrome, which is a strong risk factor for cutaneous melanoma, from not familial (sporadic) dysplastic nevus, in which the risk for melanoma would depend on the total number of melanocytic nevi, phototype, and on the relationship to environmental factors.

Small and medium-sized congenital nevi in children: a comparison of the costs of excision and long-term follow-up

BACKGROUND

Clinical decisions on whether to follow up or remove small and medium congenital melanocytic nevi (SMCMN) in children have cost implications that have not been studied.

OBJECTIVES

To compare the costs of excision of SMCMN in children with lifelong follow-up in a tertiary center.

METHODS AND MATERIALS

We elaborated models for the evaluation of the costs of excision and long-term follow-up. We retrospectively collected data on 113 consecutive excised SMCMN (105 single-step interventions and 8 multiple-step interventions) from the medical records of our pediatric dermatology unit from 2001 to 2007 and calculated and compared the costs (direct and indirect) of surgery and follow-up.

RESULTS

The mean +/- standard deviation and total cohort costs for single-step interventions were euro 1,504.73 +/- 198.33 and 157,996.20, respectively. Median and cohort lifelong follow-up costs were similar if performed every 4 years (1,482.66 +/- 34.98 and 156,679.63). For multiple-step interventions (3 or 4 steps), surgery costs were similar to those of annual lifelong follow-up. In the case of two-step surgery, costs were similar to lifelong follow-up every 2 years.

CONCLUSIONS

An analysis of the costs of surgery and long-term follow-up in children with SMCMN is possible. Although the clinical judgment of the dermatologist and parental opinion are the main determinants in the management of SMCMN, costs should also be taken into account.

Indications for excision of nevi and melanoma diagnosed in a pediatric surgical unit

BACKGROUND/PURPOSE

Childhood melanoma is rare but increasing in incidence. Its management relies on early diagnosis. The purpose of this study is to discuss surgical indications of nevi and diagnosis of melanoma in a pediatric surgical unit.

METHODS

Data relative to the patients who underwent removal of nevi in our pediatric surgical unit from 1999 to 2005 were reviewed to identify indications, histology, and melanoma occurrence.

RESULTS

The most frequent indication was atypical nevus. Compound nevus was the most common finding, followed by congenital and Spitz nevi. Melanoma was diagnosed in 3 excised nevi, and in 1 case it occurred as a metastatic disease.

CONCLUSIONS

Our data showed a pattern of indications for surgery similar to that described in the literature, with a high detection rate of melanoma, nonetheless showing that some rare conditions may delay diagnosis.

Problems in the interpretation of apparent "radial growth phase" malignant melanomas that metastasize

BACKGROUND

The delineation of radial and vertical growth phases in primary cutaneous malignant melanomas has contributed to our understanding of melanoma progression and has enhanced the ability of pathologists to provide clinicians with meaningful prognostic information. Vertical growth phase (VGP) lesions have the potential to metastasize, but radial growth phase (RGP) melanomas are believed to lack competence for metastasis.

METHODS

We have identified three cases in which metastasis occurred in association with lesions initially interpreted as RGP melanomas. To determine whether these cases truly represented exceptional metastasizing RGP melanomas or VGP lesions incorrectly identified as RGP lesions, careful microscopic re-review of these cases was performed.

RESULTS

In one case, additional microscopic sectioning revealed a focus of vertical growth that was not evident on the original sections. In the other two cases, only radial growth was found. In one of these cases there was melanoma in situ with regressive changes, but no evidence for invasive melanoma. In the other, a RGP lesion was associated with an adjacent compound nevus with periadnexal involvement.

CONCLUSIONS

These cases suggest that, while true RGP melanomas have an excellent prognosis, caution must be exercised in defining a lesion as having no metastatic potential when multiple sections of the primary lesion are unavailable, when the lesion is accompanied by regressive changes, or when there is an associated melanocytic nevus. It is possible that strictly defined RGP melanomas may metastasize in very rare cases. Our observations also suggest that metastatic potential is a function of numerous factors, and may not be evaluable on morphological grounds alone.

Primary cutaneous malignant melanoma and its precursor lesions: diagnostic and therapeutic overview

During the past few decades, scientific data relating to melanoma have flourished. New information regarding acquired nevi, dysplastic nevi (atypical nevi), and congenital nevi has given us a better understanding of these precursor lesions and their relationships to malignant melanoma. The roles of laboratory testing, photography, and newer diagnostic tools (eg, epiluminescence) to evaluate patients for melanoma or precursor lesions have fallen under close scrutiny. Traditional surgical therapeutic interventions continue to be replaced by less aggressive protocols based on prospective randomized studies. Many new interventions such as sentinel lymph node procedures are currently being evaluated at research/referral centers around the world. We present clinicians with an evidence-based summary of the current literature with regard to primary cutaneous melanoma, its diagnosis, precursor lesions, and therapy.